JUMP TO:
    Journal Publications | Published Conference Papers | Invited Talks | Book chapters/ Thesis | Miscellaneous Presentations/ Posters

    Journal Publications


    1. Angana Bhattacharya, Rakesh Sarkar and Gagan Kumar, “Excitation of near field coupled dual toroidal resonances in a bilayer terahertz metamaterial configuration.” Journal of Physics D: Applied Physics 54,285102(2021).
    2. KM Dhriti, Maidul Islam, Angana Bhattacharya, Amir Ahmad and Gagan Kumar, “ Plasmon-induced transparency in an air–dielectric grooved parallel-plate terahertz waveguide.” Journal of the Optical Society of America B 38(4),1290-1296(2021).
    3. Maidul Islam, KM Dhriti, Rakesh Sarkar, Gagan Kumar, “ Tunable control of electromagnetically induced transparency effect in a double slot terahertz waveguide.” Optics Communications 483, 126632(2021).
    4. Matthew L Chin, Sebastian Matschy, Florian Stawitzki, Jayaprakash Poojali, Hassan A Hafez, Dmitry Turchinovich, Stephan Winnerl, Gagan Kumar, Rachael L Myers-Ward, Matthew T Dejarld, Kevin M Daniels, H Dennis Drew, Thomas E Murphy, Martin Mittendorff, “ Observation of strong magneto plasmonic nonlinearity in bilayer graphene discs.” J. Phys. Photonics 3 (2021) 01LT01.
    5. KM Dhriti, Maidul Islam, Gagan Kumar, “Terahertz surface plasmon propagation in a near field coupled asymmetric resonators based planar waveguide.” Journal of Optics,22,125003(2020).
    6. KM Dhriti Maurya, Amir Ahmad, Gagan Kumar, “Planar plasmonic terahertz waveguide based upon one dimensional array of pyramidal corrugations and refractive index sensing.” IEEE Photonics Journal,12,4801010(2020).
    7. Angana Bhattacharya, Koijam Monika Devi, Tho Nguyen, Gagan Kumar, “Actively tunable toroidal excitations in graphene based terahertz metamaterials.” Optics Communications,124919(2020).
    8. Rakesh Sarkar, Koijam Monika Devi, Dipa Ghindani, S.S Prabhu, DR Chowdhury and Gagan Kumar, “Polarization independent double-band electromagnetically induced transparency effect in terahertz metamaterials.” JOurnal of Optics, 22, 035105(2020).
    9. Rakesh Sarkar, Dipa Ghindani, Koijam Monika Devi, S. S. Prabhu, AmirAhmad and Gagan Kumar, “Independently tunable electromagnetically induced transparency efect and dispersion in a multi-band terahertz metamaterial.” Scientific Reports, 9, 18068(2019).
    10. Koijam Monika Devi,Gagan Kumar, and Amarendra K. Sarma, “Surface polaritonic solitons and breathers in a planar plasmonic waveguide structure via electromagnetically induced transparency.” Journal of the optical society of America B 36(8),2160-2166(2019).
    11. Angana Bhattacharya, Koijam Monika Devi, Tho Nguyen and Gagan Kumar,“Actively tunable toroidal excitations in graphene based terahertz metamaterials.” Optics Communications, 124919 (2019).
    12. S. Jagan Mohan Rao, Rakesh Sarkar, Gagan Kumar, and D. R. Chowdhury, “Gradual Cross Polarization Conversion of Transmitted Waves in Near Field Coupled Planar Terahertz Metamaterials.” OSA Continuum 2, 603 (2019).
    13. S Jagan Mohan Rao, Yogesh Srivastava, Gagan Kumar, and Dibakar RoyChowdhury, “Modulating fundamental resonance modes in capacitive coupled asymmetric split gap ring resonator based Terahertz Metamaterials.” Scientific Reports 8, 16773 (2018).
    14. S. Jagan Mohan Rao, Gagan Kumar, Abul K. Azad, and Dibakar Roy Chowdhury, “Ultrafast Resonance Switching in Terahertz Metamaterials through Defect States in Ion implanted Silicon.” ”. Journal of Infrared, Millimeter, and Terahertz Waves 39, 1211 (2018).
    15. Koijam Monika Devi, Amarendra K. Sarma, Dibakar Roy Chowudhury and Gagan Kumar, “Dual-band electromagnetically induced transparency effect in a concentrically coupled asymmetric terahertz metamaterial.” Journal of Applied Physics (AIP) 124, 063106 (2018).
    16. Nipon Deka, Maidul Islam, Prashant K. Sarswat and Gagan Kumar, “Enhancing solar cell efficiency with plasmonic behavior of double metal nanoparticle system Author links open overlay panel.” Vacuum 152, 285 (2018).
    17. Koijam Monika Devi, Maidul Islam, Amarendra K. Sarma, Dibakar Roy Choudhury and Gagan Kumar, “Plasmon induced transparency in terahertz graphene metamaterial.” EPL (Europhysics Letters) 120 (2), 27005 (2018)
    18. Nipon Deka, Maidul Islam, Prashant K. Sarswat and Gagan Kumar, “Enhancing solar cell efficiency with plasmonic behavior of double metal nanoparticle system Author links open overlay panel. ” Vacuum 152, 285 (2018)
    19. S. Jagan Mohan Rao, Deepak Kumar, Gagan Kumar, and Dibakar Roy Chowdhury, “Modulating the near field coupling through resonator displacement in planar terahertz metamaterials”, Journal of Infrared, Millimeter, and Terahertz Waves, 38, 124–134 (2017).
    20. Maidul Islam, Dibakar Roy Chowdhury, Amir Ahmad, and Gagan Kumar, “Terahertz guided mode properties in an internally corrugated plasmonic waveguide”, AIP: Journal of Applied Physics, 122, 053105 (2017).
    21. Koijam Monika Devi, Amarendra K. Sarma, Dibakar Roy Chowdhury, and Gagan Kumar, “Plasmon induced transparency effect through alternately coupled resonators in terahertz metamaterial”, Optics Express, 25 (9), 10484-10493.
    22. S. Jagan Mohan Rao, Deepak Kumar, Gagan Kumar, Dibakar Roy Chowdhury, “Probing  the near field inductive coupling in broadside coupled terahertz metamaterials” , IEEE Journal of Selected Topics in Quantum Electronics, 23, 4700707 (2017).
    23. Maidul Islam, S Jagan Mohan Rao, Gagan Kumar, B. P. Pal and Dibakar Roy Chowdhury “Role of Resonance modes on Terahertz Metamaterials based thin film sensors” has been published in Scientific Reports, 7, 7355 (2017).
    24. Maidul Islam, Dibakar Roy Chowdhury, Amir Ahmad, and Gagan Kumar, “Terahertz Plasmonic waveguide based thin film sensor”, IEEE: Journal of light wave technology, 99, 2763326 (2017).
    25. Prashant K. Sarswat, Nipon Deka, S Jagan Mohan Rao, Michael L. Free, and Gagan Kumar, "Surface Texture-Induced Enhancement of Optical and Photoelectrochemical Activity of Cu2ZnSnS4Photocathodes", Journal of Electronics Materials, 46, 5308-5318 (2017).
    26. Maidul Islam and Gagan Kumar, “Terahertz surface plasmons propagation through periodically tilted pillars and control on directional properties.” Journal of Physics D: Applied Physics, 49, 435104 (2016).
    27. Gagan Kumar, and Prashant K. Sarswat, “Interaction of surface plasmon polaritons with nanomaterials.” Reviews of Plasmonics, Springer, pp. 103-129 (2016).
    28. S. Li, Gagan Kumar, and T. E. Murphy, “Terahertz nonlinear conduction and absorption saturation in silicon waveguides”,1Optica, 2, 553 (2015).
    29. Gagan Kumar, “Controlling terahertz surface plasmon properties on a periodically structured silicon surface”, Journal of Spectroscopy, 2015, 543985 (2015).
    30. Dhiman Bhattacharyya, Prashant K. Sarswat, Maidul Islam, Gagan Kumar, Mano Misra, and Michael L. Free, “Geometrical modifications and tuning of optical and surface plasmon resonance behaviour of Au and Ag coated TiO2 nanotubular array”, RSC Advances, 5, 70361-70370 (2015).
    31. Shanshan Li, Mohammad M. Jadidi, Thomas E. Murphy, and Gagan Kumar,“Plasmonic terahertz waveguide based on anisotropically etched silicon substrate”, IEEE Trans. Terahertz. Sci. Technol., 4, 454 (2014).
    32. J. R. Knab, X.-C. Lu, Felipe A. Vallejo, Gagan Kumar, Thomas E. Murphy, and L. Michael Hayden, “Ultrafast carrier dynamics and optical properties of nanoporous silicon at broadband terahertz frequencies”, Opt. Mater. Express, 4, 300 (2014).
    33. Manish Kumar, C. S. Suchand Sandeep, Gagan Kumar, Y. K. Mishra, R. Philip, and G. B. Reddy, "Plasmonic and Nonlinear Optical Absorption Properties of Ag:ZrO2 Nanocomposite Thin Films", Plasmonics, 9, 129-136 (2014).
    34. Gagan Kumar, Shanshan Li, Mohammad M. Jadidi and Thomas E. Murphy, “Terahertz Surface Plasmon Waveguide based on a 1-D Array of Silicon Pillars”. New Journal of Phys. 15, 085031 (2013).
    35. Shanshan Li, Mohammad M. Jadidi, Thomas E. Murphy and Gagan Kumar, “Terahertz surface plasmon polaritons on a semiconductor surface structured with periodic V-grooves”, Optics Express, 21, 7041–7049 (2013). (Corresponding author) (In top downloaded articles March & April 2013, OpEx)
    36. S.-Z. A. Lo, Gagan Kumar, Thomas E. Murphy and Edwin J. Heilweil, “Application of nanoporous silicon substrates for terahertz spectroscopy”, Opt. Mater. Express 3, 114 (2013).
    37. T. D. Nguyen, S. Liu, Gagan Kumar, A. Nahata, and Z.V. Vardeny, “THz Time Domain Spectroscopy of Graphite Films and Perforated Graphite Hole Arrays”. Appl. Phys. Lett. 102, 171107 (2013).
    38. Y. K. Mishra, R. Adelung, Gagan Kumar, M. Elbahri, S. Mohapatra, R. Singhal, A. Tripathi, and D. K. Avasthi, “Formation of self-organized silver nanocup type structures and their plasmonic absorption”, Plasmonics 8, 811-815 (2013).
    39. M. Kumar, C. S. S. Sandeep, Gagan Kumar, Y.K. Mishra, R. Philip and G.B. Reddy, “Plasmonic and non-linear optical properties of Ag:ZrO2 nanocomposite thin films”.  Plasmonics 2013.
    40. P. K. Sarswat,, M. L. Free, Gagan Kumar, “An investigation of nanocrystalline and electrochemically grown Cu2ZnSnS4 thin film using redox couples of different band offset”, Journal of Spectroscopy. 2013,  321483 (2013).
    41. Gagan Kumar, Albert Cui, Shashank Pandey, and Ajay Nahata, “Planar Plasmonics Terahertz waveguide based on periodically corrugated metal films”, New J.  Phys. 13, 033024 (2011). (Selected for Research Highlights in Nature Photonics 5, 327, June 2012.)
    42. Wenqi Zhu, Amit Agrawal, Albert Cui, Gagan Kumar, and Ajay Nahata, “Engineering the propagation properties of planar plasmonic terahertz waveguides”, IEEE J.  of Select . Topics Quant. Electron. 17, 146 (2011). (Invited
    43. Gagan Kumar, Shashank Pandey, Albert Cui, and Ajay Nahata, “Planar terahertz waveguides based on complementary split ring resonators”, Optics Express, 19, 1072 (2011).
    44. M. J. Hagmann, Gagan Kumar, Shashank Pandey, and Ajay Nahata, “Analysis and simulation of generating terahertz surface waves on a tapered field emission tip”, J. Vac. Sci. Technol. B, 29, 02B113 (2011).
    45. Shashank Pandey, Gagan Kumar, and Ajay Nahata, “Slot Waveguide-Based Splitters for Broadband Terahertz Radiation”, Optics Express, 18, 23466 (2010).
    46. Gagan Kumar and V. K. Tripathi, “Excitation of surface plasma wave over plasma cylinder by a relativistic electron beam, Phys. Plasmas, 15, 073504 (2008).
    47. Gagan Kumar and V. K. Tripathi, “Anomalous absorption of surface plasma wave by particles adsorbed on metal surface”, Appl. Phys. Lett., 91, 161503 (2007).   
    48. C. S. Liu, Gagan Kumar, D. B. Singh and V. K. Tripathi, “Electron acceleration by surface plasma waves in double metal surface structure,” J. Appl. Phys. 102, 113301 (2007).        
    49. D. B. Singh, Gagan Kumar, and V K Tripathi, “Probing of a surface plasma wave by an obliquely incident laser on the metal surface”, J. Appl. Phys. 101, 043306 (2007).        
    50. D. B. Singh, Gagan Kumar, and V K Tripathi, “Nonlinear absorption of surface plasmons and emission of electrons from metallic targets”, Phys. Plasmas., 14, 102108 (2007).                
    51. Gagan Kumar and V. K. Tripathi, “Filamentation of a surface plasma wave over a semiconductor free space interface”, J. Appl. Phys. 102, 123301 (2007).   
    52. C. S. Liu, Gagan Kumar, V. K. Tripathi, “Laser mode conversion into a surface  plasma wave in a metal coated optical fiber”, J. Appl. Phys. 100, 013304 (2006).
    53. Gagan Kumar, D. B. Singh, V. K. Tripathi, “Surface enhanced Raman scattering of a surface plasma wave”, J. Phys. D: Appl. Phys. 39, 4436-4439 (2006).

    Book Chapters/Thesis                                  


    1. Gagan Kumar and Prashant K. Sarswat, “Interaction of surface plasmon polaritons with nanomaterials.”,Reviews of Plasmonics. pp. 103-129 (2015).
    2. Gagan Kumar “ The interaction of surface plasma waves with electron beams and nanoparticle.”, Ph.D. Thesis, submitted at IIT Delhi 2008.

    Conference Papers                                  


    • Angana Bhattacharya, Koijam Monika Devi, Gagan Kumar, “Toroidal Resonances in Graphene Metamaterials” 2019 Workshop on Recent Advances in Photonics (WRAP); DOI:10.1109/WRAP47485.2019.9013713 IEEE Xplore: 27 February 2020.
    • Roopkiranpreet Kaur, Manpreet Kaur, PC Agarwal, Sukhdeep Kaur, Gagan Kumar, “Simulation of Terahertz Propagation by TE Mode in Metal Dielectric Metal Waveguide” 2019 Workshop on Recent Advances in Photonics (WRAP); DOI: 10.1109/WRAP47485.2019.9013658 IEEE Xplore: 27 February 2020.
    • KM Dhriti, Gagan Kumar, “Study of resonant modes for sensing in a multimode planar plasmonic terahertz waveguide” , 2019 Workshop on Recent Advances in Photonics (WRAP); researchgate.net Publication date 2019/12/13.
    • R Adarsh Bhargav, KM Dhriti, Angana Bhattacharya, Gagan Kumar, “ Refractive Index sensing using plasmonic mode in a periodically corrugated waveguide at terahertz frequencies” 2019 Workshop on Recent Advances in Photonics (WRAP); doi:10.1109/WRAP47485.2019.9013714 Publisher IEEE .
    • Rakesh Sarkar, Dipa Ghindani, Koijam Monika Devi, S Jagan Mohan Rao, SS Prabhu,, Gagan Kumar, “ Modulating dual-band electromagnetically induced transparency effect via near field coupling in planar terahertz metamaterials” , 2019 Workshop on Recent Advances in Photonics (WRAP); doi: 10.1109/WRAP47485.2019.9013719 IEEE Xplore: 27 February 2020.
    • Koijam Monika Devi, Rakesh Sarkar, Amarendra Kumar Sarma, Gagan Kumar, “ Exploring polarization independent plasmon induced transparency in a planar terahertz metamaterial” , 2019 Workshop on Recent Advances in Photonics (WRAP); doi: 10.1109/WRAP47485.2019.9013727 IEEE Xplore: 27 February 2020.
    • Rakesh Sarkar, Koijam Monika Devi, Dipa Ghindani, Ravikumar Jain, Arnab Pattanayak, SS Prabhu and Gagan Kumar, “Dual-band electromagnetically induced transparency effect in asymmetrically coupled terahertz metamaterials” Terahertz, 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), IEEE; 105311K (2019); doi: 10.1109/IRMMW-THz.2019.8874299 IEEE Xplore: 21 October 2019.
    • S Jagan Mohan Rao, Maidul Islam, Gagan Kumar, Bishnu P Pal, Dibakar Roy Chowdhury, “Single split gap resonator based terahertz metamaterials for refractive index sensing” Proceedings Volume 10531, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XI; 105311K (2018); doi: 10.1117/12.2287320 Event: SPIE OPTO, 2018, San Francisco, California, United States on January 27-February 1, 2018.
    • Maidul Islam, Dibakar Roy Chowdhury, and Gagan Kumar, “Planar Plasmonic Terahertz Waveguides for Sensor Applications.”, ICOLS 2018: 20th International Conference on Optics, Lasers and Spectroscopy, held in Zurich on Jan. 15-16, 2018. Best Paper Award.
    • Koijam Monika Devi, Maidul Islam, Dibakar Roy Chowdhury, Amarendra K. Sarma and Gagan Kumar, “Exploring plasmon induced transparency in graphene based terahertz metamaterials.”, Mahindra Ecole Centrale, Hyderabad. IEEE Workshop on Recent Advances in Photonics Dec. 18-19, 2017.
    • S Jagan Mohan Rao, Rakesh Sarkar, Divyam Khandelwal, Gagan Kumar and Dibakar Roy Chowdhury, “Studying the near field capacitive coupling in planar terahertz metamaterial.”, Mahindra Ecole Centrale, Hyderabad. IEEE Workshop on Recent Advances in Photonics. Dec. 18-19, 2017.
    • Maidul Islam, K M Dhriti, Dibakar Roy Chowdhury, and Gagan Kumar, “Thin film sensing in terahertz plasmonic waveguide.”, Mahindra Ecole Centrale, Hyderabad. IEEE Workshop on Recent Advances in Photonics. Dec. 18-19, 2017.
    • Sukhdeep Kaur, Manpreet Kaur, Roopkiranpreet Kaur, and Gagan Kumar, “Simulation of terahertz multimode propagation in parallel plate waveguide of metal.”, Mahindra Ecole Centrale, Hyderabad. IEEE Workshop on Recent Advances in Photonics. Dec. 18-19, 2017.
    • Maidul Islam, Dibakar Roy Chowdhury and Gagan Kumar, “Terahertz guided mode propagation in a planar plasmonic waveguide and slow light properties.”, IIT Kanpur, Kanpur. International conference Photonics-2016 to be held in Dec. 2016 at IIT Kanpur, India.
    • Koijam Monika Devi, Gagan Kumar, and Amarendra K. Sarma, “Surface Plasmon Polariton Akhmediev Breather in a dielectric-metal-dielectric multilayer structure.”, IIT Kanpur, Kanpur. International conference Photonics-2016 to be held in Dec. 2016 at IIT Kanpur, India.
    • Deepak Kumar, S. Jagan Mohan Rao, Gagan Kumar, and Dibakar Roy Chowdhury, “Modulating the Fundamental Resonances in Near Field Coupled Planar Terahertz Metamaterials.”, IIT Kanpur, Kanpur. International conference Photonics-2016 to be held in Dec. 2016 at IIT Kanpur, India.
    • Koijam Monika Devi, Amarendra K. Sarma and Gagan Kumar, “Enhanced terahertz transmission through a periodic array of tapered rectangular apertures.” 16th IUPAP Conference on Computational Physics (CCP) on Dec 2-5, 2015, IIT Guwahati, India. Proc. Journal of Physics: Conference Series (JPCS). 2016.
    • Maidul Islam and Gagan Kumar, “Terahertz surface plasmon polaritons propagation in slanted pillar geometries.”, 16th IUPAP Conference on Computational Physics (CCP) on Dec 2-5, 2015, IIT Guwahati, India. Proc. Journal of Physics: Conference Series (JPCS). 2016.
    • Sukhdeep Kaur, Sarabjeet Kaur, Manpreet Kaur and Gagan Kumar, “Numerical analysis of terahertz surface plasmon polaritons propagating in a parallel plate configuration .”, 16th IUPAP Conference on Computational Physics (CCP) on Dec 2-5, 2015, IIT Guwahati, India. Proc. Journal of Physics: Conference Series (JPCS). 2016.
    • Deepak Kumar, S. Jagan Mohan Rao, Gagan Kuma, and Dibakar Roy Chowdhury, “Engineering the Resonances in Coupled Bilayer Terahertz Metamaterials.”, 4th International Conference on Nanoscience and Nanotechnology (ICONN-2017) to be held at SRM University . Aug 9-11, 2017. (Accepted).
    • Jyoti Thakur, Deepak Kumar, Gagan Kumar and Manish K. Kashyap, “Search of magnetism in Mn-doped Silicene; A DFT approach”. Proc. National Conference on Physics of Engineering Materials (NCPEM-2016) in Deenbandhu Chhotu Ram University of Science & Technology, Murthal, Haryana. March 10-11, 2016.
    • Gagan Kumar, “Engineering terahertz propagation properties using plasmonic metamaterials on silicon”. Proc. 12th International Conference on Fiber Optics and Photonics (Photonics 2014) at IIT Kharagpur, India. Dec. 13-16, 2014
    • S. Li, Gagan Kumar, T. E. Murphy “Terahertz Absorption Saturation in Intrinsic Silicon Dielectric Ridge Waveguides”, Conference on Lasers and Electro-optics (CLEO), San Jose, CA (USA) STh3F.3 (2014).
    • Gagan Kumar, S. Li, M. M. Jadidi, T. E. Murphy, “Anisotropically Etched Silicon Surfaces for Planar Plasmonic Terahertz Guided Wave Devices”, CLEO: Applications and Technology San Jose, California United States June 8-13, 2014 JW2A.97 (2014).
    • Mohammad Jadidi, Gagan Kumar, Shanshan Li, Thomas Murphy, “Terahertz plasmonic waveguide based on periodically structured silicon surface”. Proc. Conference on Laser and Electro-Optics Sampling (CLEO) 2013, San Jose June 9-14, California.
    • Gagan Kumar, Albert Cui and Ajay Nahata, “Terahertz Guided-Wave Devices using periodically patterned dimple structures,” Proc. Conference on Lasers and Electro-Optics Sampling (CLEO), May 16-21, 2010.
    • M. J. Hagmann, Gagan Kumar, Ajay Nahata, “Analysis and Simulation of Generating Terahertz Surface Waves on a Tapered Field Emission Tip” Proc. 23rd International Vacuum Nanoelectronics Conference, Palo Alto, California July 26-30, 2010.
    • T.D. Nguyen, S. Liu, Gagan Kumar, A. Nahata and Z.V. Vardeny, “THz Time domain Spectroscopy Studies of Graphite films and perforated graphite hole array” APS March meeting March 15-19, 2010, Portland, OR.

    •  

      Invited Talks                                   


    • Gagan Kumar, “Terahertz Plasmonic and Metamaterials Devices”, QIP Short Term Course on “Industrial Applications of Terahertz Radiation”. March 27th to April 2nd, 2017. Department of Physics, IIT Kharagpur, Kharagpur-721302, India.
    • Gagan Kumar, “THz Photonics”, TEQIP Short Term Course on “Advances in Photonics”, Feb. 25-26, 2016. Department of Electrical and Communication Engineering, IIT Guwahati, Guwahati, Assam-781039, India.
    • Gagan Kumar, “Planar Plasmonic Terahertz Waveguides”. International Conference on High Power Coherent Radiation Generation and Its Interaction With Matter, Feb. 12-14, 2016, Vidisha (M.P.), India.
    • Gagan Kumar, “Terahertz guided wave devices using plasmonic metamaterials”. 16th IUPAP Conference on Computational Physics (CCP) on Dec 2-5, 2015, IIT Guwahati, Assam, India.
    • Gagan Kumar, “Significance of ultrashort pulses for terahertz generation and detection”. Talk in the seminar series celebrating International Year of Light, Sept. 29, 2015.
    • Gagan Kumar, “Terahertz plasmonic metamaterials”. on April 10, 2015 in the short term course on Fundamentals and Applications of Metamaterials – 2015 at IIT Kanpur, Kanpur, India
    • Gagan Kumar, “Terahertz Photonics”, Department of Physics, Indian Institute of Technology (IIT) Kanpur, India on April 10, 2015.
    • Gagan Kumar “Terahertz plasmonics” on Jan. 3, 2015 in the Department of Physics, IIT Guwahati, Guwahati-781039, India.
    • Gagan Kumar “Terahertz Science and Applications”, in the Department of Physics, Kurukshetra University Kurukshetra on Feb. 10, 2015.
    • Gagan Kumar “Terahertz plasmonic waveguides” The 12th International Conference on Fiber Optics and Photonics (Photonics 2014), Dec. 13-16, IIT Kharagpur, India.
    • Gagan Kumar “Planar Plasmonic THz Waveguides Using Thin Structured Metal Films”, in the Center for Applied Electromagnetic at the University of Maryland, Nov. 2, 2010.

Miscellaneous                                    


    1. SJM Rao, M. Islam, Gagan Kumar and D. R. Chowdhury, “Numerical Study of Resonance modes in Terahertz Metamaterials for thin film sensing perspective”. Presented in SPIE Photonic West 2018 held from January 27-February 1, 2018 at The Moscone Center San Francisco, California, United States.
    2. S Jagan Mohan Rao, Gagan Kumar and Dibakar Roy Chowdhury, “Tuning near field capacitive coupling in planar terahertz metamaterials”. Presented in SPIE Photonic West 2018 held from January 27-February 1, 2018 at The Moscone Center San Francisco, California, United States.
    3. S. Jagan Mohan Rao1, Maidul Islam, Gagan Kumar , Bishnu P. Pal and Dibakar Roy Chowdhury, “Resonance Mode Study in Planar Terahertz Metamaterials Towards Thin Film Sensing Perspective”. Poster presented in ‘International Conference on Advances in Optics and Photonics (ICAOP 2017)’ at Guru Jambheshwar University of Science and Technology Hisar, Haryana held on Nov. 23-26, 2017.
    4. Maidul Islam, K M Dhriti, Dibakar Roy Chowdhury, and Gagan Kumar, “Thin Film Sensing in Terahertz Plasmonic Waveguide”. Poster presented in IEEE Workshop on Recent Advances in Photonics, Dec. 18-19, 2017, Mahindra Ecole Centrale, Hyderabad.
    5. K. M. Devi, M. Islam, D. R. Chowdhury, A. K. Sarma and Gagan Kumar “Exploring plasmon induced transparency in graphene based terahertz metamaterials”. Poster presented in IEEE Workshop on Recent Advances in Photonics, Dec. 18-19, 2017, Mahindra Ecole Centrale, Hyderabad.
    6. SJM Rao, R. Sarkar, D. Khandelwal, Shahjahan, Gagan Kumar, D. R. Chowdhury, “Studying the near field capacitive coupling in planar terahertz metamaterial”. Poster presented in IEEE Workshop on Recent Advances in Photonics, Dec. 18-19, 2017, Mahindra Ecole Centrale, Hyderabad.
    7. Dibakar Roy Chowdhury, S Jagan Mohan Rao, and Gagan Kumar, “Analyzing the near field electromagnetic coupling in terahertz metamaterials”. Presented in ‘International Conference on Advances in Optics and Photonics (ICAOP 2017)’ at Guru Jambheshwar University of Science and Technology Hisar, Haryana held on Nov. 23-26, 2017.
    8. S Jagan Mohan Ra, Gagan Kumar, Dibakar Roy Chowdhury, “Exploring the near field inductive coupling in broadside coupled terahertz metamaterials.” Poster presented in ‘International Conference on Advances in Optics and Photonics (ICAOP 2017)’ at Guru Jambheshwar University of Science and Technology Hisar, Haryana held on Nov. 23-26, 2017.
    9. Deepak Kumar, S. Jagan Mohan Rao, Ranjan Kumar, Gagan Kumar and Dibakar Roy Chowdhury, “Electromagnetic Resonances in Coupled Metamaterials”, Poster presented in ‘International Conference on Advances in Optics and Photonics (ICAOP 2017)’ at Guru Jambheshwar University of Science and Technology Hisar, Haryana held on Nov. 23-26, 2017.
    10. Gagan Kumar, Koijam Monika Devi, Amarendra K. Sarma and Dibakar Roy Chowdhury, “Modulating Plasmon Induced Transparency in Terahertz Metamaterials”. Presented in ICOP 2017: 19th International Conference on Optics and Photonics held in Singapore, SG on November, 9-10, 2017.
    11. Maidul Islam and Gagan Kumar, “Terahertz surface plasmon polaritons propagation in slanted pillar geometries.” 16th IUPAP Conference on Computational Physics (CCP) on Dec 2-5, 2015, IIT Guwahati, Assam, India.
    12. Koijam Monika Devi, Amarendra K. Sarma and Gagan Kumar, “Enhanced terahertz transmission through a periodic array of tapered rectangular apertures.” 16th IUPAP Conference on Computational Physics (CCP) on Dec 2-5, 2015, IIT Guwahati, Assam, India.
    13. D. Bhattacharyya, P. K. Sarswat, Maidul Islam, Gagan Kumar, Mano Misra, and Michael L. Free, “Optical and surface plasmon resonance behaviour of Au and Ag coated TiO2 nanotube arrays,” Int’l Year of Light Symposium, Oct. 31, 2015 in the Department of Physics at IIT Guwahati.
    14. Gagan Kumar, “Terahertz Plasmonic Waveguides”, Department of Physics, Indian Institute of Technology (IIT) Kanpur, India on April 10, 2015.
    15. Gagan Kumar, “Terahertz Plasmonic Metamaterials and Guided Wave Devices”, Department of Physics, Indian Institute of Technology (IIT) Delhi, India on Oct. 21, 2015
    16. Gagan Kumar, “Terahertz Plasmonic Metamaterials”, Department of Physics, Indian Institute of Technology (IIT) Ropar, India on Feb. 13, 2015
    17. Gagan Kumar, “Terahertz Photonics”, Department of Physics, Indian Institute of Science Education and Research (IISER) Mohali, India on Feb. 9, 2015.
    18. Gagan Kumar, Shanshan Li, Thomas E. Murphy, “Plasmonic Terahertz Waveguide Based on Pyramidal Troughs Etched in Silicon”. The 5th International conference on Metamaterials, Photonic Crystals and Plasmonics (META’14) at Nanyang Technological University (NTU) Singapore. May 20-23, 2014.
    19. Gagan Kumar “Plasmonics and Nanoporous materials - devices and applications”, Department of Physics, University of Chicago, USA on April 19, 2013.
    20. Mohammad Jadidi, Gagan Kumar, Shanshan Li, Thomas Murphy, “Terahertz plasmonic waveguide based on periodically structured silicon surface”. CLEO 2013, San Jose June 9-14, California.
    21. S. Liu, T. Nguyen, Gagan Kumar, Z. Valy Vardeny and Ajay Nahata, “Terahertz plasmonic properties of Carben-based materials”, International workshop on Optical Terahertz Science and Technology (OTST), Kyoto Terrsa, Japan, April 1-5, 2013.
    22. Gagan Kumar, Shashank Pandey and Ajay Nahata, “Planar Terahertz Waveguides Based on Complementary Split Ring Resonators,” International workshop on Optical Terahertz Science and Technology (OTST), Santa Barbara, CA, March 13-17, 2011.
    23. Shashank Pandey, Gagan Kumar and Ajay Nahata, “Slot Waveguide-Based Splitters for Broadband Terahertz Radiation”, International workshop on Optical Terahertz Science and Technology (OTST), Santa Barbara, CA, March 13-17, 2011.
    24. M. J. Hagmann, Gagan Kumar, S. Pandey and A. Nahata, “Analysis and simulation of generating terahertz surface waves in laser assisted field emission”, Bulletin of the American Physical Society, vol. 56, no. 1, March 21-25, 2011, Dallas, Texas.
    25. Gagan Kumar, Albert Cui and Ajay Nahata, “Terahertz Guided-Wave Devices using periodically patterned dimple structures,” International Conference on lasers and electro-optics sampling (CLEO), May 16-21, 2010.
    26. Gagan Kumar, W. Zhu, A. Cui and A. Nahata, “Planar terahertz guided-wave devices using plasmonic metamaterials,” International Conference on Metamaterials, Photonic Crystals and Plasmonics (META'10) – Cairo, Egypt (2010). Presented, February 2010.
    27. Gagan Kumar, W. Zhu, A. Cui and A. Nahata, “Using plasmonic metamaterials to create terahertz guided-wave circuits,” 13th European Microwave Week 2010– Paris, France (2010). Presented, June 2010.
    28. Gagan Kumar, C. S. Liu and V. K. Tripathi “Electron acceleration by surface plasma waves on a metal surface” in ‘Summer College on Plasma Physics-New Developments 2007’ held on 30 July - 24 August 2007 in Abdus Salam International Center for Theoretical Physics (ICTP) – Trieste, Italy
    29. Gagan Kumar and V. K. Tripathi, “Modeling of SERS Sensor in an attenuated total reflection (ATR) configuration”, 21st National Symposium on Plasma Science and Technology, MNIT Jaipur, India, Dec. 19-23, 2006.
    30. Gagan Kumar and V. K. Tripathi, “Laser mode conversion into a surface plasma wave”, Proc. 20th National Symposium on Plasma Science and Technology, CUSAT, Cochin, India, Dec. 5-7, 2005.