Publications / Journals / Conferences 

Presentations 
 N. K. Nishchal, “Generation and detection of structured light beams and its applications,” XLVII OSI Symposium – International Conference on Advances in Optics and Photonics Instrumentation (OPTOIn2024), Oct. 2325, 2024, CSIO Chandigarh [Invited].
 R. Kumar, A. Pal, N. K. Nishchal, and A. Alfalou, “Multitarget detection through waveletmodified maximum average correlation height filter,” OPTICA Frontiers in Optics Meeting on Information Acquisition, Processing and Display (FiO + LS2024), Sept. 2326, 2024, Denver, Colorado, USA.
 A. Pal, R. Kumar, Jyothish M., and N. K. Nishchal, “Inplane rotation estimation through composite filter synthesis and logpolar mapping,” OPTICA Frontiers in Optics Meeting on Information Acquisition, Processing and Display (FiO + LS2024), Sept. 2326, 2024, Denver, Colorado, USA.
4. S. K. Rao, R. Kumar, N. K. Nishchal, and A. Alfalou, “Optical image encryption using modified GS algorithm and DNA encoding,” OPTICA Frontiers in Optics Meeting on Information Acquisition, Processing and Display (FiO + LS2024), Sept. 2326, 2024, Denver, Colorado, USA. 5. M. Baliyan and N. K. Nishchal, “Controlled generation of Poincare BesselGaussian beams,” OPTICA Frontiers in Optics Meeting on Information Acquisition, Processing and Display (FiO + LS2024), Sept. 2326, 2024, Denver, Colorado, USA. 6. R. Kumar and N. K. Nishchal, “Phase imaging from Xray intensity images using transport of intensity equation,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2024), W4A.23, June 0306, 2024, Paestum, ITALY. 7. S. K. Rao and N. K. Nishchal, “Optical asymmetric colorimage encryption using vector light field encoding,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2024), W4A.36, June 0306, 2024, Paestum, ITALY. 8. J. B. Mohapatra, R. Kumar, Jyothish M., and N. K. Nishchal, “Chirpencoded fringeadjusted joint transform correlator for 3D object recognition using Fresnel holography,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2024), W4A.12, June 0306, 2024, Paestum, ITALY. 9. A. Shikder and N. K. Nishchal, “Multiple image encryption using radial modes of light beam,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2024), W4A.35, June 0306, 2024, Paestum, ITALY. 10. N. K. Nishchal, “Information security using the properties of optical vortex lattice,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2024), M4B.6, June 0306, 2024, Paestum, ITALY [Invited]. 11. N. K. Nishchal, “Vortex beam array for securing information,” International Conference on Sustainanble Nanomaterials Integration and Oraganization for Energy and Environment (iSNIOE2), March 2023, 2024, Shiv Nadar University, Greater Noida [Invited]. 12. A. Shikder and N. K. Nishchal, “Application of optical vortex in image encryption,” XLVI OSI SymposiumInternational Conference on Optics, Photonics & Quantum Information (OPTIQ2023), Dec. 1113, 2023, CUSAT Cochin [Invited]. (Couldn’t present) 13. A. Shikder, J. B. Mohapatra, and N. K. Nishchal, “Fractional topological charge measurement of optical vortex beam using joint transform correlator,” XLVI OSI SymposiumInternational Conference on Optics, Photonics & Quantum Information (OPTIQ2023), Dec. 1113, 2023, CUSAT Cochin. 14. J. B. Mohapatra, A. Pal, M. Jyothish, and N. K. Nishchal, “Object detection in foggy and hazy conditions,” XLVI OSI SymposiumInternational Conference on Optics, Photonics & Quantum Information (OPTIQ2023), Dec. 1113, 2023, CUSAT Cochin. 15. A. Pal, J. B. Mohapatra, Joythish M., and N. K. Nishchal, “Binary differential joint transform correlator based rotation angle estimation,” Sixth IEEE International Workshop on Recent Advances in Photonics (WRAP2023), Dec. 0709, 2023, IIIT Allahabad. 16. M. Baliyan and N. K. Nishchal, “Generating multiple polarization singularities through noninterferometric technique,” Sixth IEEE International Workshop on Recent Advances in Photonics (WRAP2023), Dec. 0709, 2023, IIIT Allahabad. 17. S. K. Rao and N. K. Nishchal, “Vectorial light field encoding for asymmetric encryption,” Sixth IEEE International Workshop on Recent Advances in Photonics (WRAP2023), Dec. 0709, 2023, IIIT Allahabad. 18. A. Shikder, S. K. Rao, P. Kumar, and N. K. Nishchal, “Image encoding using dual phase modulation,” Sixth IEEE International Workshop on Recent Advances in Photonics (WRAP2023), Dec. 0709, 2023, IIIT Allahabad. 19. N. K. Nishchal, “Optical cryptography through optical vortex,” Topical Conference to Commemorate the Birth Centenary of Professor Manoranjan De (IConTop2023), Nov. 2425, 2023, Calcutta University, Kolkata [Invited]. 20. R. Kumar, A. Shikder, N. K. Nishchal, A. AlFalou, “Recognition of optical vortex modes assisted by a MACH filter,” Topical Conference to Commemorate the Birth Centenary of Professor Manoranjan De (IConTop2023), Nov. 2425, 2023, Calcutta University, Kolkata. 21. A. Shikder and N. K. Nishchal, “Information encoding through binary polarization states,” Topical Conference to Commemorate the Birth Centenary of Professor Manoranjan De (IConTop2023), Nov. 2425, 2023, Calcutta University, Kolkata. 22. R. Kumar, N. K. Nishchal, and A. AlFalou, “Modified extended maximu average correlation height filter for target identification,” OPTICA Frontiers in Optics: Information Acquisition, Processing and Display (FiO72023), Oct. 0912, 2023, Tacoma, Washington, USA. 23. M. Baliyan and N. K. Nishchal, “Optical image encryption using nonseparable vector beams,” OPTICA Frontiers in Optics: Information Acquisition, Processing and Display (FiO72023), Oct. 0912, 2023, Tacoma, Washington, USA. 24. A. Shikder and N. K. Nishchal, “Generation of controllable optical vortex array by inline phase modulation with a light emitting diode,” OPTICA Frontiers in Optics: Information Acquisition, Processing and Display (FiO72023), Oct. 0912, 2023, Tacoma, Washington, USA. 25. M. Baliyan and N. K. Nishchal, “Generation of vector Bessel modes using spiral axicon hologram,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2023), Aug. 1417, 2023, Boston, Massachusetts, USA. 26. S. K. Rao and N. K. Nishchal, “Fullyphase image encryption and watermarking using structured phase masks,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2023), Aug. 1417, 2023, Boston, Massachusetts, USA. 27. A. Shikder and N. K. Nishchal, “Generation of vector vortex beam using partially coherent light,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2023), Aug. 1417, 2023, Boston, Massachusetts, USA. 28. M. Baliyan and N. K. Nishchal, “Generation of scalar beams fully manipulated in amplitude and wavefront,” 8th Int’l. Conference on Women in Physics (ICWIP2023), Homi Bhabha Centre for Science Education (HBCSE), Mumbai, July 0914, 2023. 29. A. Shikder, R. Kumar, N. K. Nishchal, and A. AlFalou, “Optical vortex latticebased image encoding,” International Conference on Photonics (PHOTONICS2023), IISc Bangalore, July 0508, 2023. 30. A. Shikder and N. K. Nishchal, “Optical image encryption with structured light,” International Conference on Complexity and Nonlinear Dynamics in Science, Technology, Engineering & Mathematics, IIT Hyderabad, June 0507, 2023 [Invited]. 31. J. B. Mohapatra, A. Pal, J. Jojy, and N. K. Nishchal, “Waveletmodified logarithmic fringeadjusted joint transform correlator,” International Conference on Complexity and Nonlinear Dynamics in Science, Technology, Engineering & Mathematics, IIT Hyderabad, June 0507, 2023. 32. A. Pal, J. B. Mohapatra, J. Jojy, and N. K. Nishchal, “Logpolar mapped phaseonly filter for distortioninvariant target identification,” IndoFrench Conference on Frontiers in Photonics and Metamaterials (IFCFPM2023), Mahindra University, Hyderabad, April 2122, 2023. 33. A. Shikder and N. K. Nishchal, “Fractional topological charge measurement of optical vortex beam using spiral interferometer,” IndoFrench Conference on Frontiers in Photonics and Metamaterials (IFCFPM2023), Mahindra University, Hyderabad, April 2122, 2023. 34. A. Shikder and N. K. Nishchal, “Binary image encoding through optical vortex lattice,” IndoFrench Conference on Frontiers in Photonics and Metamaterials (IFCFPM2023), Mahindra University, Hyderabad, April 2122, 2023. 35. A. Shikder and N. K. Nishchal, “Optical vorticesbased image encryption,” International Seminar on Atomic Process, Laser, Nanomaterial and Terahertz Technology for Optical Fiber Communication (LNTOFC2023), M L S College, Madhubani, Feb. 0910, 2023 [Invited]. 36. P. Kumar and N. K. Nishchal, “Image encryption through structured light,” XLV Annual Symposium of OSI as Conference on Optics, Photonics, and Quantum Optics (COPaQ2022), IIT Roorkee, Nov. 1013, 2022 [Invited]. 37. M. Baliyan and N. K. Nishchal, “Generation of cylindrical vector beam using noninterferometric dual phase modulation,” XLV Annual Symposium of OSI as Conference on Optics, Photonics, and Quantum Optics (COPaQ2022), IIT Roorkee, Nov. 1013, 2022. 38. R. Kumar, A. Shikder, N. K. Nishchal, and A. AlFalou, “Orbital angular momentum mode identification of vortex beam using optical correlation,” XLV Annual Symposium of OSI as Conference on Optics, Photonics, and Quantum Optics (COPaQ2022), IIT Roorkee, Nov. 1013, 2022. 39. A. Shikder and N. K. Nishchal, “Generation of higher order array of vortices through inline wavefront shaping using spatial light modulator,” XLV Annual Symposium of OSI as Conference on Optics, Photonics, and Quantum Optics (COPaQ2022), IIT Roorkee, Nov. 1013, 2022. 40. N. K. Nishchal, “Optoelectronic asymmetric cryptosystem,” Int’l. Confer. on Electronic Materials and Applications (ICEMA2022), Sept. 1617, 2022, A. N. College, Patna [Invited]. 41. R. Kumar, N. K. Nishchal, and A. AlFalou, “Pattern identification using MACH filter through optical correlation,” Int’l. Confer. on Electronic Materials and Applications (ICEMA2022), Sept. 1617, 2022, A. N. College, Patna. 42. A. Shikder and N. K. Nishchal, “Optical vortex lattice generation through inline phase modulation,” Int’l. Confer. on Electronic Materials and Applications (ICEMA2022), Sept. 1617, 2022, A. N. College, Patna. 43. N. K. Nishchal, “Structured light for information security,” Int’l. Confer. on Defence Research, Innovation and Technology (ICDRIT2022), Sept. 1516, 2022, Gujarat University, Ahmedabad, Souvenir, pp. 1013 (2022). 44. A. Shikder and N. K. Nishchal, “Computer generated hologram encryption using array of vortex beams,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2022), Aug. 0104, 2022, Robinson College, Cambridge University, Cambridge, UK. 45. A. Shikder, N. K. Nishchal, and P. Kumar, “Production of structured light beams through inline wavefront shaping using spatial light modulator,” OPTICA Digital Holography and ThreeDimensional Imaging (DH2022), Aug. 0104, 2022, Robinson College, Cambridge University, Cambridge, UK. 46. P. Kumar, N. K. Nishchal, T. Omatsu, and A. S. Rao, “A compact optical setup to create nonuniformly polarized highorder structured light beams,” Confer. on Lasers and Electrooptics, PacificRim 2022, (CLEOPR 2022, ISOM’22, ODF’22), Sapporo, JAPAN, July 31Aug. 06, 2022. 47. P. Kumar, N. K. Nishchal, T. Omatsu, and A. S. Rao, “Optimization of spatial light modulator’s phase response through computergenerated hologram,” OPTICAImaging and Applied Optics Congress, Vancouver, British Columbia, CANADA, July 1115, 2022. 48. N. K. Nishchal, “Optical techniques for information security,” 2nd Int’l. Scientific Confer. (Hybrid) on Lasers, Optics. Photonics and Sensors (LOPS2022), June 1012, 2022, Fort Lauderdale, FL, USA [Invited]. 49. N. K. Nishchal, “Vector beam for information encoding,” Golden Jubilee Year Int’l. Confer. on Artificial Intelligence, Photonics, and Revolutionary Smart Materials (AIPRSM2021), Oct. 2526, 2021, L. N. Mithila Univ., Darbhanga [Invited]. 50. N. K. Nishchal, “Optical cryptography,” 2nd Edition – Laser, Optics, and Photonics Virtual (VOptics2021), Oct. 1617, 2021 [Keynote Talk]. 51. A. K. Gupta and N. K. Nishchal, “Transport of intensity equation for lowlight quantitative phase imaging and security applications,” Holography, Diffractive Optics, and Applications; SPIE/COS Photonics Asia 2021 (PA21), Oct. 1012, 2021, Jiangsu, CHINA [Invited], Proc. SPIE 11898 (2021) 118980W. 52. N. K. Nishchal, “Image encryption using vector beam,” 2nd Int’l. Confer. on Digital Singular Optics: Applications and Fundamentals (DSO2021), Sept. 0610, 2021, Yalta, RUSSIA [Invited]. 53. P. Kumar and N. K. Nishchal, “Vector field encoding approach to secure color image,” OSA Imaging and Applied Optics Congress: Digital Holography and ThreeDimensional Imaging (DH2021), July 1923, 2021 (Online). 54. A. K. Gupta and N. K. Nishchal, “Composite method of transport of intensity equation for spatial frequency recovery,” OSA Imaging and Applied Optics Congress: Digital Holography and ThreeDimensional Imaging (DH2021), July 1923, 2021 (Online). 55. P. Kumar and N. K. Nishchal, “Creation and detection of singular light beams,” Student Conference on Photonics and Quantum Technology (CPQT2021), Feb. 2426, 2021, NISER Bhubaneswar (Online) [Invited]. 56. P. Kumar and N. K. Nishchal, “Generation of singular beams using electrically addressed spatial light modulator,” 5th Int’l. Confer. on Emerging Electronics, Nov. 2628, 2020 (Online), IIT Delhi. 57. N. K. Nishchal, “A practical optical cryptosystem with partially coherent illumination,” Online Summit on Optics and Photonics (COP2020), Nov. 2627, 2020, Lisbon, PORTUGAL [Invited]. 58. P. Kumar and N. K. Nishchal, “Optical singularities in tailored light fields,” OSA Siegman International School on Lasers, July 2024, 2020 (Online), Warsaw, POLAND. 59. P. Kumar and N. K. Nishchal, “Selfreferenced interferometric methods to determine topological charge of vortex beams,” OSA Topical Meeting on Digital Holography and 3D Imaging (DH2020), June 2226, 2020 (Online). 60. P. Kumar and N. K. Nishchal, “Cylindrical vector beams by tailoring single polarization component,” OSA Topical Meeting on Digital Holography and 3D Imaging (DH2020), June 2226, 2020 (Online). 61. A. K. Gupta, P. Kumar, and N. K. Nishchal, “Fullyphase encryption using transport of intensity equation,” OSA Topical Meeting on Digital Holography and 3D Imaging (DH2020), June 2226, 2020 (Online). 62. A. K. Gupta, P. Kumar, and N. K. Nishchal, “Transport of intensity equationbased image encryption,” Int’l. OSA Network of Students Conference 2020 (IONS2020), Feb. 29March 02, 2020, IIT Delhi. 63. A. Kumar, R. K. Jha, and N. K. Nishchal, “Chromaticity weighted regularization technique for image dehazing,” Int’l. OSA Network of Students Conference 2020 (IONS2020), Feb. 29March 02, 2020, IIT Delhi. 64. P. Kumar and N. K. Nishchal, “Topological charge estimation of vortex beams through conjoined forklike fringe pattern,” Int’l. OSA Network of Students Conference 2020 (IONS2020), Feb. 29March 02, 2020, IIT Delhi. 65. P. Kumar and N. K. Nishchal, “Determining orbital angular momentum of light by analyzing interferogram with conjoined forklike structures,” Workshop on Recent Advances in Photonics (WRAP2019), Dec. 1314, 2019, IIT Guwahati. 66. A. K. Gupta and N. K. Nishchal, “Transport of intensity equation for phase imaging,” 20th Int’l. Symp. on Optomechatronic Technologies (ISOT2019), Nov. 1113, 2019, Goa [Invited]. 67. P. Kumar and N. K. Nishchal, “Selfreferenced interferogram of LaguerreGaussian beams for topological charge determination,” 20th Int’l. Symp. on Optomechatronic Technologies (ISOT2019), Nov. 1113, 2019, Goa. 68. P. Kumar, A. Kumar, and N. K. Nishchal, “LEDbased implementation of exclusiveOR operation for securing QR code,” Int’l. Confer. on Optics and Electrooptics (XLIII Symp. of Optical Society of India) (ICOL2019), Oct. 1922, 2019, IRDE Dehradun [Invited]. 69. A. Fatima and N. K. Nishchal, “Denoising imaging polarimetry by total variation reduction,” Int’l. Confer. on Optics and Electrooptics (XLIII Symp. of Optical Society of India) (ICOL2019), Oct. 1922, 2019, IRDE Dehradun. 70. A. Kumar, R. K. Jha, and N. K. Nishchal, “A weighted multiscale fusion technique for single image haze removal,” Int’l. Confer. on Optics and Electrooptics (XLIII Symp. of Optical Society of India) (ICOL2019), Oct. 1922, 2019, IRDE Dehradun. 71. P. Kumar and N. K. Nishchal, “Selfreferenced interferometric technique for determining highorder topological charges of vortex beams,” Int’l. Confer. on Optics and Electrooptics (XLIII Symp. of Optical Society of India) (ICOL2019), Oct. 1922, 2019, IRDE Dehradun. 72. A. K. Gupta and N. K. Nishchal, “Transport of intensity based photon counting phase imaging for noninvasive applications,” Int’l. Confer. on Optics and Electrooptics (XLIII Symp. of Optical Society of India) (ICOL2019), Oct. 1922, 2019, IRDE Dehradun. 73. A. K. Gupta and N. K. Nishchal, “Single shot transport of intensity equation based phase imaging using refractive index variation,” M5B.4, OSA Topical Meeting on Digital Holography and 3D Imaging (DH2019), May 1923, 2019, Bordeaux, FRANCE. 74. A. K. Gupta, A. Fatima, and N. K. Nishchal, “Phase imaging based on transport of intensity equation using liquid crystal variable waveplate,” M5B.7, OSA Topical Meeting on Digital Holography and 3D Imaging (DH2019), May 1923, 2019, Bordeaux, FRANCE. 75. P. Kumar and N. K. Nishchal, “Optical cryptosystems with quick response code,” Information Photonics2019 (IP19), April 2426, 2019, Yokohama, JAPAN [Invited]. 76. N. K. Nishchal, “Securing information through light,” Int’l. Confer. on Photonics, Metamaterials, and Plasmonics (PMP2019), Feb. 1416, 2019, JIIT Noida [Invited]. 77. P. Kumar, A. Fatima, and N. K. Nishchal, “Multiple image security scheme based on Stokes parameter of spatially varying polarized beam,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2018), Dec. 1215, 2018, IIT Delhi. 78. A. K. Gupta and N. K. Nishchal, “A noninterferometric phase retrieval using liquid crystal spatial light modulator,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2018), Dec. 1215, 2018, IIT Delhi. 79. A. Kumar and N. K. Nishchal, “A multispectral image fusion technique based on single level integer wavelet transform,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2018), Dec. 1215, 2018, IIT Delhi. 80. Yatish, A. Fatima, and N. K. Nishchal, “Twostage optical hierarchical authentication based on interference with sparse phase information,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2018), Dec. 1215, 2018, IIT Delhi. 81. A. Fatima and N. K. Nishchal, “Image encryption by phase and polarization modulation of light,” 7th Bihar Science Conference, An Int’l. Confer. on Science & Technology (BSC2018), Dec. 0406, 2018, College of Commerce, Arts, and Science, Patna. 82. N. K. Nishchal, “Vector beam with required phaseonly functions for asymmetric image encryption,” XLII Annual Meeting of the Optical Society of IndiaInt’l. Symp. on Optics (OSIISO2018), Sept. 1922, 2018, IIT Kanpur [Invited]. 83. P. Kumar and N. K. Nishchal, “Generation of optical angular momentum of light using liquid crystal spatial light modulator,” XLII Annual Meeting of the Optical Society of IndiaInt’l. Symp. on Optics (OSIISO2018), Sept. 1922, 2018, IIT Kanpur. 84. A. K. Gupta and N. K. Nishchal, “Phase retrieval with liquid crystal variable retarder based on referenceless noninterferometric technique,” XLII Annual Meeting of the Optical Society of IndiaInt’l. Symp. on Optics (OSIISO2018), Sept. 1922, 2018, IIT Kanpur. 85. A. Fatima and N. K. Nishchal, “Simultaneous authentication verification of multiple secured images using joint transform correlation approach,” SPIE Security + Defence, Electrooptical and Infrared Systems: Technology and Applications, Sept. 1013, 2018, Berlin, GERMANY. 86. N. K. Nishchal, “Optical asymmetric encryption schemes and attack analysis,” SPIE Security + Defence, Electrooptical and Infrared Systems: Technology and Applications, Sept. 1013, 2018, Berlin, GERMANY. 87. A. Fatima, N. K. Nishchal, Y. Queo, A. Alfalou, and C. Brosseau, “Polarizationbased encoding for optical cryptosystems,” 2nd Joensuu Confer. on Coherence & Random Polarization; Trends in Electromagnetic Coherence (COHERENCE2018), June 1215, 2018, Joensuu, FINLAND. 88. A. Fatima, N. K. Nishchal, A. Alfalou, and C. Brosseau, “Securing image authentication using a vector beam analysis,” 2nd Joensuu Confer. on Coherence & Random Polarization; Trends in Electromagnetic Coherence (COHERENCE2018), June 1215, 2018, Joensuu, FINLAND. 89. R. Shekhar, G. Unnikrishnan, and N. K. Nishchal, “Reconstruction quality improvement of digital holograms using multiscale globa search,” JW4A.8 Digital Holography and 3D Imaging (Topical meeting), OSA Imaging and Applied Optics Congress, June 2528, 2018, Orlando, Florida, USA. 90. R. Shekhar, G. Unnikrishnan, and N. K. Nishchal, “Multiplexing multiple digital holograms for efficient transmission and recovery,” JM4A.33 Digital Holography and 3D Imaging (Topical meeting), OSA Imaging and Applied Optics Congress, June 2528, 2018, Orlando, Florida, USA. 91. A. K. Gupta and N. K. Nishchal, “Phase characterization of a liquid crystal spatial light modulator,” 3rd Int’l. Confer. on Microwave and Photonics (ICMAP2018), Feb. 0911, 2018, IIT (ISM) Dhanbad, pp. 37. 92. A. Kumar and N. K. Nishchal, “An image encryption scheme using quick response code,” 3rd Int’l. Confer. on Microwave and Photonics (ICMAP2018), Feb. 0911, 2018, IIT (ISM) Dhanbad, pp. 48. 93. N. K. Nishchal, “Optical security,” Workshop on Recent Advances in Photonics (WRAP2017), Dec. 1819, 2017, Mahindra Ecole Centrale, Hyderabad [Invited]. 94. A. Kumar and N. K. Nishchal, “A noise induced cryptographic hash function based on double random gyrator domain phase encoding,” Int’l. Confer. on Advances in Optics & Photonics (ICAOP2017), Nov. 2326, 2017, Hisar. 95. A. Fatima and N. K. Nishchal, “Information security through polarization encoding,” Int’l. Confer. on Advances in Optics & Photonics (ICAOP2017), Nov. 2326, 2017, Hisar [Invited]. 96. A. Fatima and N. K. Nishchal, “Phase modulation based optical asymmetric image encryption,” OSA Frontiers in Optics + Laser Science APS/DLS (FiO+LS 2017), Sept. 1721, 2017, Washington, USA. 97. T. Pitkaaho, V. Pitkakangas, M. Niemela, S. K. Rajput, N. K. Nishchal, and T. J. Naughton, “Digital holographic sensor network and image analyses for distributed potable water monitoring,” Irish Machine Vision and Image Processing Conference (IMVIP2017), Aug. 30Sept. 01, 2017, Maynooth Univ., IRELAND. 98. N. K. Nishchal, “Optical encryption schemes,” UEM Congress 2017, Disruptive Technology & Disruptive Innovation – A Renaissance in this Century, Aug. 1618, 2017, Sasin Graduate Institute of Business Administration, Cholalongkorn University, Bangkok, THAILAND [Invited]. 99. A. Kumar and N. K. Nishchal, “Quick response codebased asymmetric image encryption scheme,” Int’l. Topical Meeting on Applied and Adaptive Optics (INTOPMAA17), Aug. 1113, 2017, IIST Trivandrum. 100. Yatish, A. Fatima and N. K. Nishchal, “Multiple image encryption using unity modulus decomposition,” Int’l. Topical Meeting on Applied and Adaptive Optics (INTOPMAA17), Aug. 1113, 2017, IIST Trivandrum. 101. A. Fatima and N. K. Nishchal, “Asymmetric optical encryption schemes,” Int’l. Topical Meeting on Applied and Adaptive Optics (INTOPMAA17), Aug. 1113, 2017, IIST Trivandrum [Invited]. 102. T. Pitkaaho, V. Pitkakangas, M. Niemela, S. K. Rajput, N. K. Nishchal, and T. J. Naughton, “Digital holographic microscopy in remote potable water monitoring,” The Digital Holography and 3D Imaging (Topical meeting), May 29June 01, 2017, Cheju Halla University, Jeju Island, SOUTH KOREA. 103. N. K. Nishchal, “Securing 3D information using digital holography,” The Digital Holography and 3D Imaging (Topical meeting), Th1A.2. May 29June 01, 2017, Cheju Halla University, Jeju Island, SOUTH KOREA [Invited]. 104. A. Fatima and N. K. Nishchal, “Image encryption using Hartley transform domain polarization encoding,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2016), Dec. 0408, 2016, IIT Kanpur. 105. N. K. Nishchal, “Securing digital holograms through watermarking,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2016), Dec. 0408, 2016, IIT Kanpur. 106. Yatish, A. Fatima and N. K. Nishchal, “Barcodebased watermarking and optical encryption,” The Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS2016), Dec. 0408, 2016, IIT Kanpur. 107. A. Fatima and N. K. Nishchal, “Asymmetric optical cryptosystem; Attack analysis,” Int’l. Confer. on Light and Lightbased Technologies (ICLLT2016), Nov. 2628, 2016, Tezpur Univ. 108. D. Kumar and N. K. Nishchal, “Digital holography for recognition and information security of 3D objects,” 3rd Int’l. Confer. on Optoelctronics & Applied Optics (OPTRONIX2016), Aug. 1820, 2016, Univ. of Engineering & Management, Kolkata [Invited]. 109. A. Fatima and N. K. Nishchal, “Single public key dependent attack on optical asymmetric cryptosystem,” 3rd Int’l. Confer. on Optoelctronics & Applied Optics (OPTRONIX2016), Aug. 1820, 2016, Univ. of Engineering & Management, Kolkata. 110. N. K. Nishchal, “Optical security for future era,” IEEE 5G Summit, March 2931, 2016, IIT Patna. 111. N. K. Nishchal, “Optical asymmetric cryptosystem and cryptanalysis,” Int’l. Confer. on OptoElectronics and Applied Optics, (IEEE IEM OPTRONIX2015) Oct. 1617, 2015, Univ. of British Columbia, Vancouver, CANADA [Invited]. 112. D. Kumar and N. K. Nishchal, “Threedimensional object recognition using phaseonly computergenerated Fresnel hologram,” Int’l. Confer. on OptoElectronics and Applied Optics, (IEEE IEM OPTRONIX2015) Oct. 1617, 2015, Univ. of British Columbia, Vancouver, CANADA. 113. I. Mehra and N. K. Nishchal, “Optical asymmetric cryptosystem and wavelet based image fusion,” Int’l. Symp. on 3D Imaging, Metrology, Data Security (3DIMDS 2015), Sept. 2629, 2015, Shenzen, CHINA [Invited]. 114. D. Kumar and N. K. Nishchal, “Phaseonly computer generated Fresnel hologram synthesis using a symmetrical threedimensional GS algorithm,” Siegman International School on Lasers: 2015, Aug. 0207, 2015, Amberg, GERMANY. 115. D. Kumar and N. K. Nishchal, “Digital holography based 3D object recognition under varying light illumination using photon counting imaging,” Int’l. Confer. on Digital Holography & 3D Imaging, May 2428, 2015, Shanghai Institute of Optics and Fine Mechanics, Shanghai, CHINA. 116. I. Mehra and N. K. Nishchal, “Double image encryption using gyrator wavelet transform,” Int’l. Confer. on Optics & Photonics (ICOP2015), Feb. 2022, 2015, Univ. of Calcutta. 117. D. Kumar, S. K. Rajput, and N. K. Nishchal, “Hologram watermarking with color image via phase multiplexing and photon counting imaging technique,” Int’l. Confer. on Optics & Photonics (ICOP2015), Feb. 2022, 2015, University of Calcutta. 118. D. Kumar and N. K. Nishchal, “Digital holography for threedimensional object recognition,” 6th Bihar Science Conference; An Int’l. Confer. on Science & Technology, Dec. 2325, 2014, Magadh Mahila College, Patna. 119. D. Kumar and N. K. Nishchal, “Performance enhancement of joint fractional correlator for digital holography based threedimensional object recognition using wavelet filter,” Int’l. Confer. on Optoelectronics and Applied Optics (IEMOPTRONIX2014), Dec. 1718, 2014, IEM Kolkata. 120. I. Mehra and N. K. Nishchal, “Pansharpened image optical encryption,” Int’l. Confer. on Optoelectronics and Applied Optics (IEMOPTRONIX2014), Dec. 1718, 2014, IEM Kolkata. 121. S. K. Rajput and N. K. Nishchal, “Simultaneous encryption of grayscale and color images,” 12th Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’14), Dec. 1316, 2014, IIT Kharagpur. 122. D. Kumar and N. K. Nishchal, “Digital holography based threedimensional object recognition using binary differential joint transform correlator,” 12th Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’14), Dec. 1316, 2014, IIT Kharagpur. 123. A. Fatima, I. Mehra, and N. K. Nishchal, “Plasmonicsbased keys for optical image encryption,” 12th Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’14), Dec. 1316, 2014, IIT Kharagpur. 124. I. Mehra and N. K. Nishchal, “Optical asymmetric cryptosystem based on axial translation of image sensor,” 12th Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’14), Dec. 1316, 2014, IIT Kharagpur. 125. A. Fatima, I. Mehra, D. Kumar, and N. K. Nishchal, “Plasmonics based keys for image encryption that uses exclusive OR logic operation,” COMSOL Conference 2014, Bangalore, Nov. 1314, 2014. 126. N. K. Nishchal, “3D optical information security,” Collaborative Conference on 3D & Materials Research (CC3DRM2014), June 2327, 2014, Incheon, Seoul, SOUTH KOREA [Invited]. 127. D. Kumar and N. K. Nishchal, “Identification of threedimensional objects using nonlinear joint fractional Fourier transform correlator,” XVI Annual Confer. of Int’l. Academy of Physical Sciences on Physical Sciences and Technology for Sustainable Development (CONIAPS’14), March 2022, 2014, IIITDM Jabalpur. 128. D. Kumar and N. K. Nishchal, “Identification of threedimensional objects using nonconventional joint fractional Fourier transform correlator,” Int’l. Confer. on Optics & Optoelectronics (ICOL’14), March 0508, 2014, Dehradun. 129. N. K. Nishchal and S. K. Rajput, “Optical asymmetric cryptosystem,” Int’l. Confer. on Optics & Optoelectronics (ICOL’14), March 0508, 2014, Dehradun. 130. I. Mehra and N. K. Nishchal, “Securing image using interference and diffractive imaging,” Int’l. Confer. on Optics & Optoelectronics (ICOL’14), March 0508, 2014, Dehradun. 131. S. K. Rajput and N. K. Nishchal, “Optical decryption of asymmetric cryptosystem based on phasetruncated Fourier transform,” Int’l. Confer. on Optics & Optoelectronics (ICOL’14), March 0508, 2014, Dehradun. 132. I. Mehra and N. K. Nishchal, “Multiple image hiding based on joint transform correlator and modified GerchbergSaxton phase retrieval algorithm” Int’l. Confer. on Opticsphotonics Design & Fabrication, 13PSb04, 287288, Feb. 1214, 2014, Tokyo, JAPAN. 133. I. Mehra and N. K. Nishchal, “A novel asymmetric cryptosystem for securing multiple images,” Int’l. Confer. on Opticsphotonics Design & Fabrication, 13PSb05, 289290, Feb. 1214, 2014, Tokyo, JAPAN. 134. N. K. Nishchal, “Digital holographic microscopy,” Int’l. Confer. on Role of Science and Technology in Progress of World,” Desidoc, DRDO, Dec. 0507, 2013. 135. S. K. Rajput and N. K. Nishchal, “Optical asymmetric cryptosystem using polarized light,” Int’l. Confer. on 2013 Optical Engineering + Applications in SPIE Optics + Photonics, Aug. 2529, 2013, San Diego, USA. Proc. SPIE 8855 (2013) 885503. 136. S. K. Rajput and N. K. Nishchal, “Knownplaintext attack on asymmetric cryptosystem,” Int’l. Confer. on 2013 Optical Engineering + Applications in SPIE Optics + Photonics, Aug. 2529, 2013, San Diego, USA. Proc. SPIE 8855 (2013) 88550U. 137. S. K. Rajput and N. K. Nishchal, “Multiple image encryption based on knownplaintext attack and modified GS phase retrieval algorithm,” International Conference on Optics in Precision Engineering and Nanotechnology (icOPEN 2013) April 911, 2013, Singapore Expo, SINGAPORE, Proc. SPIE 8769 (2013) 87690X. 138. S. K. Rajput and N. K. Nishchal, “Fractional domain asymmetric cryptosystem and cryptanalysis,” International Conference on Optics in Precision Engineering and Nanotechnology (icOPEN 2013) April 911, 2013, Singapore Expo, SINGAPORE, Proc. SPIE 8769 (2013) 87691Y [Invited paper]. 139. I. Mehra, S. K. Rajput, and N. K. Nishchal, “Collision in phase truncation based asymmetric cryptosystem in Fresnel domain,” Eleventh Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’12), IIT Madras, Dec. 0912, 2012. 140. S. K. Rajput, Himanshu, and N. K. Nishchal, “Color image encryption using polarized light,” Eleventh Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’12), IIT Madras, Dec. 0912, 2012. 141. N. K. Nishchal, T. Pitkaaho, S. Krishnan, and A. Maninnen, “Realtime threedimensional visualization of Escherichia coli using digital holographic microscope,” Eleventh Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’12), IIT Madras, Dec. 0912, 2012. 142. S. K. Rajput and N. K. Nishchal, “Image encryption based on phasetruncation and interference using fractional Fourier transform,” First International OSA Network of Students (IONS) Conference, IIT Delhi, Dec. 0102, 2011. 143. S. K. Rajput and N. K. Nishchal, “Joint fractional Fourier transform correlator for encrypted image verification,” Photonics Ireland 2011, Sept. 0709, 2011, Dublin, IRELAND. 144. N. K. Nishchal, “Effect of image processing operations on fractional Fourier transform based image watermarking technique,” Photonics Ireland 2011, Sept. 0709, 2011, Dublin, IRELAND. 145. N. K. Nishchal and T. J. Naughton, “Reconstruction of Fresnel digital hologram using fractional Fourier transform algorithm,” Tenth Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’10), IIT Guwahati, Dec. 1115, 2010. 146. M. R. Ansari and N. K. Nishchal, “Securing watermarked information using fractional Fourier transform,” Tenth Int’l. Confer. on Fiber Optics and Photonics (PHOTONICS’10), IIT Guwahati, Dec. 1115, 2010. 147. N. K. Nishchal, “Fractional Fourier domain optical image watermarking,” Proc. of 16th Microoptics Conference (2010 MOC), pp. 8485, Oct. 31Nov. 3, 2010, Hsinchu, TAIWAN. 148. N. K. Nishchal, “Waveletbased distortioninvariant correlation filters; A review,” Proc. of 16th Microoptics Conference (2010 MOC), pp. 326327, Oct. 31Nov. 3, 2010, Hsinchu, TAIWAN. 149. N. K. Nishchal, T. Pitkaaho, and T. J. Naughton, “Digital Fresnel hologram watermarking,” Proc. of 9th EuroAmerican Workshop on Information Optics (WIO 2010), July 1116, 2010, Helsinki, FINLAND. cc.oulu.fi/~tpitaa/varasto/05582496.pdf 150. N. K. Nishchal and T. J. Naughton, “Threedimensional image watermarking using fractional Fourier transform,” Proc. of Int’l Confer. on Optics and Photonics (ICOP2009), CSIO Chandigarh, Oct. 30Nov. 01, 2009. 151. N. K. Nishchal and T. J. Naughton, “Threedimensional optical image encryption using fractional Fourier transform,” Ninth Int’l Confer. on Optoelectronics, Fiber Optics, and Photonics (PHOTONICS’08), IIT Delhi, Dec. 1317, 2008. 152. A. Bhagatji, N. K. Nishchal, A. K. Gupta, and B. P. Tyagi, “Fringeadjusted filterbased fractional joint transform correlator,“ IndoJapan Workshop on Recent Developments in Optics and Photonics, IIT Delhi, Dec. 14, 2007, pp. 133136. 153. V. K. Beri, S. Goyal, N. K. Nishchal, and A. K. Gupta, “Waveletmodified maximum average correlation height filter for outofplane rotation invariance,” Eighth Int’l Confer. on Optoelectronics, Fiber Optics, and Photonics (PHOTONICS’06), Dec. 1316, 2006, Hyderabad. 154. A. Aran, N. K. Nishchal, and V. K. Beri, “Logpolar transform based wavelet modified maximum average correlation height filter for rotation and scale invariant target recognition,” Eighth Int’l Confer. on Optoelectronics, Fiber Optics, and Photonics (PHOTONICS’06), Dec. 1316, 2006, Hyderabad. 155. S. Goyal, N. K. Nishchal, and V. K. Beri, “Chirpencoded MACH filterbased hybrid digitaloptical correlator,” Int’l Confer. on Optics and Optoelectronics, IRDE Dehradun, Dec. 1215, 2005. 156. A. Bhagatji, N. K. Nishchal, and V. K. Beri, “Influence of perturbations in a hybrid digitaloptical correlator,” Int’l. Confer. on Optics and Optoelectronics, IRDE Dehradun, Dec. 1215, 2005. 157. A. Kumar, N. K. Nishchal, and A. K. Gupta, “Genetic algorithm for composite waveletmatched filter with application to outofplane rotated targets,” Int’l Confer. on Optics and Optoelectronics, IRDE Dehradun, Dec. 1215, 2005. 158. K. Singh and N. K. Nishchal, “Applications of fractional Fourier transform in optical data security,” Proc. Int’l Confer. on Optoelectronic Technology, (Nirali Prakashan, Pune, 2004), Ed., D. K. Gautam, Jan. 1214, 2004, North Maharashtra Univ., Jalgaon, pp. 244266. 159. N. K. Nishchal, R. John, and K. Singh, “Optical data security and holographic storage,” Proc. Int’l Confer. on Laser Applications and Optical Metrology, Eds. C. Shakher and D. S. Mehta, (Anamaya Publs., New Delhi, 2004) Dec. 0104, 2003, IIT Delhi, New Delhi, pp. 126134. 160. N. K. Nishchal, J. Joseph, and K. Singh, “Data security using digital holography,” Proc. Int’l Confer. on Laser Applications and Optical Metrology, Eds. C. Shakher and D. S. Mehta, (Anamaya Publs., New Delhi, 2004) Dec. 0104, 2003, IIT Delhi, New Delhi, pp. 563567. 161. N. K. Nishchal, J. Joseph, and K. Singh, “Fully phase encryption using fractional Fourier transform,” Proc. Sixth Int’l Confer. on Optoelectronics, Fiber Optics, and Photonics (PHOTONICS’02), Dec. 1618, 2002, TIFR Mumbai. 162. N. K. Nishchal and K. Singh, “Fractional Fourier transform techniques in optical data security,” Proc. Int’l Confer. on Optoelectronics and Laser Applications, Oct. 0203, 2002, Jakarta, INDONESIA, pp. D04D08. 163. N. K. Nishchal, J. Joseph, and K. Singh, “Optical phase encryption system that uses phase conjugation and phase contrast,” Proc. 3rd Int’l Confer. on OpticsPhotonics Design & Fabrication (ODF’02), Oct. 30Nov. 01, 2002, Tokyo, JAPAN, pp. 141142. 164. N. K. Nishchal, J. Joseph, and K. Singh, “Phase contrast using electrically addressed liquid crystal spatial light modulator,” Proc. 3rd Int’l. Confer. on OpticsPhotonics Design & Fabrication (ODF’02), Oct. 30Nov. 01, 2002, Tokyo, JAPAN, pp. 109110. 165. N. K. Nishchal, J. Joseph, and K. Singh, “A multichannel optical wavelet processor,” 2nd Int’l Confer. & 27th Annual Convention of Opt. Soc. India, Aug. 2729, 2001, Trivandrum, India.

Invited Talks 
 N. K. Nishchal, “Photorefractive optics,” Refresher Course on XRay Crystallography, and XRay Photoelectron Spectroscopy with Density Functional Theory Calculations, IIT (ISM) Dhanbad, Aug. 26, 2024.
 N. K. Nishchal, “Optical technology for information security,” One Day Seminar on Advances in Photonics, IIT Bhubaneswar, March 22, 2024.
 N. K. Nishchal, “Optical cryptography through structured light,” Department of Physics, Indian Institute of Space Science and Technology, Thiruvananthapuram, Feb. 15, 2024.
 N. K. Nishchal, “Optical cryptography through structured light,” Short Course on Emerging Materials and their Societal Impacts, NIT Patna, Nov. 0610, 2023.
 N. K. Nishchal, “Securing information with structured light,” Department of Physics, Sikkim University, Gangtok, May 24, 2023.
 N. K. Nishchal, “Interference in thin films and digital holographic microscopy,” DSTSTUTI sponsored handson training program on Training for Developing Skills on Research Equipment in Physics and Biotechnology, Central University of South Bihar, Gaya, Jan. 21, 2023.
 N. K. Nishchal, “Interference and diffraction of light,” REvitalizing School Physics Education through Conceptoriented Teaching in Bihar for PGTs, IIT Patna, Jan. 18, 2023.
 N. K. Nishchal, “Understanding physics: Classes IXX,” Instructional School for Mathematical Foundation for Classes XIXII, Dept. of Mathematics, IIT Patna, Oct. 16, 2022.
 N. K. Nishchal, “Understanding wave optics,” Instructional School for Mathematical Foundation for Classes XIXII, Dept. of Mathematics, IIT Patna, Oct. 10, 2022.
 N. K. Nishchal, “Digital holographic microscope,” Workshop on Highend Equipments: Fabrication & Characterization of Electronic Devices, SERBIIT Patna, July 26, 2022.
 N. K. Nishchal, “Optical encryption,” Summer School on Optics and Photonics, Optics and Photonics Centre, IIT Delhi, June 14, 2022.
 N. K. Nishchal, “Optics and photonics for the benefit of society,” Popular lecture during ‘Vigyan Sarvatra Pujyate’, Shrikrishna Science Centre, Patna, Feb. 28, 2022.
 N. K. Nishchal, “Light in energy conservation,” National Energy Conservation Day, The Institution of Engineers, Bihar State Centre, Patna, Dec. 14, 2021.
 N. K. Nishchal, “Photonics technology,” World Standards Day, Bureau of Indian Standards, Patna, Oct. 29, 2021.
 N. K. Nishchal, “Photorefractive optics,” Faculty Development Programme on Novel Materials under AICTE Training and Learning (ATAL) Academy, A. N. College, Patna, Aug. 27, 2021.
 N. K. Nishchal, “Photonics for society,” Webinar, Bhagalpur College of Engineering, Bhagalpur, Sept. 18, 2020.
 N. K. Nishchal, “Photonics in the digital era; UV light killer of Corona virus,” Webinar, Bakhtiyarpur College of Engineering, Bakhtiyarpur, Aug. 09, 2020. https://www.youtube.com/watch?v=QTK4gq0vDg
 N. K. Nishchal, “Light as a tool for development,” Webinar, Gaya Engineering College, Gaya, Aug. 06, 2020.
 N. K. Nishchal, “Light for information encoding,” Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, May 10, 2019.
 N. K. Nishchal, “Vector beam based asymmetric image encryption,” Faculty of Systems Engineering, Wakayama University, Wakayama, JAPAN, April 23, 2019.
 N. K. Nishchal, “Light for information security,” Department of Applied Optics and Photonics, University of Calcutta, Kolkata, April 01, 2019.
 N. K. Nishchal, “Vector beam with required phaseonly functions for image encryption,” Centre for Nonlinear Science, Westfalische WilhelmsUniversitat, Muenster, GERMANY, Sept. 14, 2018.
 N. K. Nishchal, “Physical optics and holography,” Workshop at Delhi Public School, Patna, August 18, 2018.
 N. K. Nishchal, “Light for information encoding,” REvitalizing School Physics Education through Conceptoriented Teaching in KVs (RESPECT KVs) for PGTs, IIT Patna, August 07, 2018.
 N. K. Nishchal, “Tools and techniques of space exploration,” On the occasion of Moon Landing Day at Srikrishna Vigyan Kendra, Patna, July 20, 2018.
 N. K. Nishchal, “Holography and its applications,” REvitalizing School Physics Education through Conceptoriented Teaching in KVs (RESPECT KVs) for PGTs, IIT Patna, July 18, 2018.
 N. K. Nishchal, “Optics for information security,” Refresher Programme in Physics, Faculty Development Centre, IIT (ISM) Dhanbad, June 13, 2018.
 N. K. Nishchal, “Information optics,” Refresher Programme in Physics, Faculty Development Centre, IIT (ISM) Dhanbad, June 12, 2018.
 N. K. Nishchal, “Diffraction and Interference,” REvitalizing School Physics Education through Conceptoriented Teaching in KVs (RESPECT KVs) for PGTs, IIT Patna, April 0709, 2017.
 N. K. Nishchal, “Basics of wave optics,” REvitalizing School Physics Education through Conceptoriented Teaching in KVs (RESPECT KVs) for PGTs, IIT Patna, Oct. 21, 2016.
 N. K. Nishchal, “Techniques of optical information security,” Special Lecture to M. Phil. Students, Department of Physics, B. R. A. Bihar University, Muzaffarpur, Sept. 20, 2015.
 N. K. Nishchal, “Digital holography and image encryption techniques,” 15^{th} Refresher Course, University Department of Physics, B. R. A. Bihar University, Muzaffarpur, Feb. 04, 2015.
 N. K. Nishchal, “Basics of optics: interference, diffraction, and polarization,” 15^{th} Refresher Course, University Department of Physics, B. R. A. Bihar University, Muzaffarpur, Feb. 03, 2015.
 N. K. Nishchal, “Optical techniques of image encryption, watermarking, and 3D target identification,” 3D Display Research Centre, Department of Electronics Engineering, Kwangwoon University, Seoul, SOUTH KOREA, June 28, 2014.
 N. K. Nishchal, “Digital holography and its applications,” Seminar on Laser and its Applications, University Department of Physics, B. R. A. Bihar University, Muzaffarpur, March 31, 2014.
 N. K. Nishchal, “Understanding fiberoptic communication,” Inservice Course of PGT (Physics) Kendriya Vidyalaya Sangathan, Kendriya Vidyalaya, Bailey Road, Patna, Dec. 24, 2013.
 N. K. Nishchal, “Interference and diffraction of light,” Bihar INSPIRE Internship Science Camp, Jagdam College Chapra, Oct. 31, 2013.
 N. K. Nishchal, “Optical watermarking techniques,” Room No. 321, Department of Physics, Capital Normal University, Beijing, CHINA, June 24, 2013.
 N. K. Nishchal, “Optical image encryption techniques,” Room No. 321, Department of Physics, Capital Normal University, Beijing, CHINA, June 20, 2013.
 N. K. Nishchal, “Wave optics,” Inservice Course of PGT (Physics) Kendriya Vidyalaya Sangathan, Kendriya Vidyalaya, Bailey Road, Patna, May 22, 2013.
 N. K. Nishchal, “Lasers and its applications,” INSPIRE (Innovation in Science Pursuit for Inspired Research) Internship Science Camp, PreExamination Training Centre, Patna Univ., March 18, 2013.
 N. K. Nishchal, “Optical pattern recognition and information security,” One Day Workshop on Optical Signal and Image Processing Techniques, Jan. 19, 2013, VIT University, Chennai.
 N. K. Nishchal, “Microscopes,” Bihar INSPIRE Internship Science Camp, Jagdam College Chapra, Jan. 16, 2013.
 N. K. Nishchal, “Digital holography,” One Day Seminar on Development of NanoTechnology Sensors for Defence Applications: NanoScale Innovation, Vidyadaan Institute of Technology and Management, Dumraon, Buxar, Sept. 16, 2012.
 N. K. Nishchal, “Optical microscope,” INSPIRE (Innovation in Science Pursuit for Inspired Research) Internship Science Camp, PreExamination Training Centre, Patna Univ., Aug. 30, 2012.
 N. K. Nishchal, “Photonic correlator,” Bihar INSPIRE Internship Science Camp, Jagdam College Chapra, July 18, 2012.
 N. K. Nishchal, “Optical information processing,” Contact Programme for Talented +2 School Students, at the Mahavir Cancer Sansthan & Research Centre, Patna, April 26, 2012.
 N. K. Nishchal, “Holography and its applications,” INSPIRE (Innovation in Science Pursuit for Inspired Research) Internship Science Camp, PreExamination Training Centre, Patna University, Feb. 27, 2012.
 N. K. Nishchal, “Optoelectronic techniques of image encryption, watermarking, and target identification,” Department of Computer Science, National University of Ireland Maynooth, IRELAND, Sept. 12, 2011.
 N. K. Nishchal, “Optoelectronic techniques of information security,” Bihar INSPIRE Internship Science Camp, Jagdam College Chapra, Aug. 07, 2011.
 N. K. Nishchal, “Optoelectronic techniques of 3D information security,” at Industrial Technology Research Institute, Hsinchu, TAIWAN, Nov. 04, 2010.
 N. K. Nishchal, “Laser and its applications,” Motivation Programme for Talented School Students of +2, at the Mahavir Cancer Sansthan, Patna, Sept. 24, 2010.
 N. K. Nishchal, “Optical information processing using Matlab,” Short Term Training Programme on “Exposure on MATLAB,” at the National Institute of Technical Teachers’ Training & Research Extension Centre, Guwahati, March 13, 2008.
