Journal Publications
• Significant enhancement in THz emission and piezoelectricity in atomically thin Nb-doped MoS2. Neetesh Dhakar, Z Pin, H Y Lee, S-W Kim, B Kumar and Sunil Kumar ACS Applied Materials & Interfaces (2024). Link
• THz probing of non-trivial topological states in Co2MnGe Heusler alloy thin films. Ekta Yadav, A Nivedan and Sunil Kumar Submitted (2024). Link
• Analysis of Stokes singularities using lateral shear interferometer. Rahul Joshi, B Komal, Sunil Kumar, P Senthilkumaran Optics Continuum 3, 1180 (2024). Link
• Unveiling surface and bulk contributions in THz emission from Bi2Te3. Anand Nivedan and Sunil Kumar New Journal of Physics 26, 033044 (2024). Link
• Intrinsic free carrier absorption limited THz generation from Bi2Te3 and Bi2Se3 topological insulators. Anand Nivedan and Sunil Kumar Applied Physics Letters 124, 091109 (2024). Link
• Polarization singularity index determination using wedge plate lateral shear interferometry. Baby Komal, R Joshi, Sunil Kumar and P Senthilkumaran Optics and Lasers in Engineering 177, 108119 (2024). Link
• Terahertz optical fibers in Roadmap on specialty optical fibers Anjali and Sunil Kumar Journal of Physics: Photonics (2024). Link
• Probing defect induced room temperature ferromagnetism in Chemical Vapor Deposition grown MoO3 flakes: A correlation with electronic structure and first principle-based calculations. Sharmistha Dey, V Mishra, N Dhakar, Sunil Kumar, P Srivastava, S Ghosh Journal of Alloys and Compounds 980, 173650 (2024). Link
• Ultrafast THz probing of nonlocal orbital current in transverse multilayer metallic heterostructures. Sandeep Kumar and Sunil Kumar Nature Communications 14, 8185 (2023). Link
• Ultrafast terahertz spin and orbital transport in magnetic/nonmagnetic multilayer heterostructures and a perspective. Sandeep Kumar and Sunil Kumar Journal of Applied Physics 134, 170901 (2023). Link
• Intrinsically dominated anomalous Hall effect in epitaxial Co2MnGe ferromagnetic full Heusler alloy thin films. Ekta Yadav and Sunil Kumar RSC Advances 13, 30101 (2023). Link
• Resistive switching and battery-like characteristics in highly transparent Ta2O5/ITO thin-films. Darshika Khone, S Kumar, M Balal, SR Barman, Sunil Kumar and AS Rana Scientific Reports 13, 14297 (2023). Link
• An interplay between optical rectification and transient photocurrent effect on THz pulse generation from bulk MoS2 layered crystal. Neetesh Dhakar, S Kumar, A Nivedan and Sunil Kumar Journal of Physics D: Applied Physics 56, 435105 (2023). Link
• Excitation wavelength-dependent ultrafast THz emission from surface and bulk of three-dimensional topological insulators. Anand Nivedan and Sunil Kumar Journal of Physics D: Applied Physics 56, 255101 (2023). Link
• Actively tunable Graphene ribbon based multi-band THz polarizer with a high extinction ratio. Anjali, RK Varshney and Sunil Kumar Journal of the Optical Society of America B 40, 1688 (2023). Link
• Strong impact of crystalline twins on the amplitude and azimuthal dependence of THz emission from epitaxial NiO/Pt. Rekha Agarwal, S Kumar, N Chowdhury, KIA Khan, E Yadav, Sunil Kumar and PK Muduli Applied Physics Letters 122, 082403 (2023). Link
• Role of symmetry in self-healing of singular beams. Baby Komal, G Arora, Sunil Kumar and P Senthilkumaran Applied Physics B 129, 29 (2023). Link
• Hybrid thermo-physical modelling and experimentation of ultrafast laser-based fabrication of polycrystalline core-amorphous shell nitinol nanoparticles. Vinod Parmar, S Singh, A Singh, Sunil Kumar, D Kalyanasundaram Optics and Laser Technology 165, 109575 (2023). Link
• Visible and NIR-Light Photoactivatable o-Hydroxycinnamate System for Efficient Drug Release with Fluorescence Monitoring. Ajay Gupta, N Singh, A Gautam, N Dhakar, Sunil Kumar and P Sasmal RSC Med. Chem. 14, 1088-1100 (2023). Link
• Role of position specific Ga and N vacancy in tailoring the ferromagnetic properties of thin GaN films. Sharmistha Dey, P Singh, V Mishra, N Dhakar, Sunil Kumar, F Singh, P Srivastava, S Ghosh Solid State Communications 371, 115232 (2023). Link
• Generation and beam steering of THz radiation in an actively modulated nonlinear crystal. Vikas Kumar, R Varshney and Sunil Kumar Optics Communications 526, 128950 (2022). Link
• Functional Thin Films for Perovskite Solar Cells. Feng Wang and Sunil Kumar Coatings 12, 952 (2022). Link
• Large interfacial contribution to ultrafast THz emission by inverse spin Hall effect in CoFeB/Ta heterostructure. Sandeep Kumar and Sunil Kumar iScience 25, 104718 (2022). Link See the Supplementary Information also.
• Ultrafast light-induced THz switching in exchange-biased Fe/Pt spintronic heterostructure. Sandeep Kumar and Sunil Kumar Applied Physics Letters 120, 202403 (2022). Link Published as Editor's pick article in the Journal.
• Ultrafast, broadband and tunable THz reflector and neutral density filter based on high resistivity silicon. Jerome Degert, M Tondusson, V Freysz, E Abraham, Sunil Kumar and E Freysz Optics Express 30, 18995-19004 (2022). Link
• THz photonics and optoelectronics of carbon-based nanosystems. Arvind Singh and Sunil Kumar Journal of Applied Physics 131, 160901 (2022). Link
• Self-healing of vector field singularities. Baby Komal, G Arora, Sunil Kumar and P Senthilkumaran Optics Communications 524, 128796 (2022). Link
• Phonon Bottleneck in Temperature-Dependent Hot Carrier Relaxation in Graphene Oxide. Arvind Singh and Sunil Kumar Journal of Physical Chemistry C 125, 26583 (2021). Link
• Optical Damage Limit of Efficient Spintronic THz Emitters. Sandeep Kumar, A Nivedan, A Singh, Y Kumar, P Malhotra, M Tondusson, E Freysz, and Sunil Kumar iScience 24, 103152 (2021). Link See the Supplementary information also.
• Sub-bandgap activated charges transfer in a graphene-MoS2-graphene heterostructure. Sunil Kumar, A Singh, A Nivedan, S Kumar, SJ Yun, YH Lee, M Tondusson, J Degert, J Oberle, E Freysz Nano Select 2(10), 2019 (2021). Link See the Supplementary information also.
• Plasmonic charge transfers in large-scale metallic and colloidal photonic crystal slabs. Swagato Sarkar, V Gupta, T Tsuda, J Gour, A Singh, O Aftenieva, A M Steiner, M Hoffmann, Sunil Kumar, A Fery, J Joseph, TAF König Advanced Functional Materials 31, 2011099 (2021). Link
• Mitochondria-Targeted Photoactivatable Real-Time Monitoring of a Controlled Drug Delivery Platform. Neelu Singh, P Prasad, RK Sah, A Gupta, A Singh, Sunil Kumar, S Singh, S Gupta, and PK Sasmal Journal of Medicinal Chemistry 64, 17813 (2021). Link
• THz pulses from optically excited Fe, Pt and Ta based Spintronic Heterostructures. Sandeep Kumar, A Nivedan, A Singh and Sunil Kumar Pramana Journal of Physics 95, 75 (2021). Link Preprint at https://arxiv.org/abs/2101.04969
• Enhancement in optically induced ultrafast THz conductivity in MoSe2MoS2 heterobilayer. Sunil Kumar, A Singh, S Kumar, A Nivedan, M Tondusson, J Degert, J Oberle, SJ Yun, YH Lee, E Freysz Optics Express 29(3), 4181-4190 (2021). Link See the Supplementary information also.
• Emergence and origin of temperature-dependent white-light emission from two-dimensional hybrids. Madhu Bochalya, A Nivedan, S Kumar, A Singh, and Sunil Kumar Journal of Materials Chemistry C 9, 5998 (2021). Link
• Temperature-dependent ultrafast response and pi-plasmon dynamics in single walled carbon nanotubes. Arvind Singh, S Kumar, A Nivedan, and Sunil Kumar Journal of Physical Chemistry Letters 12, 627-632 (2021). Link
• Helicity inversion and generation of orthogonal, degenerate index states of generic C points. Baby Komal, S Deepa, SK Pal, BS Bhargava Ram, Sunil Kumar, and P Senthilkumaran Journal of Optics 23, 114001 (2021). Link
• Polarization singularity index determination by using a tilted lens. Baby Komal, D Sathyanarayanan, Sunil Kumar, P Senthilkumaran Applied Optics 60, 3266 (2021). Link
• Thermo-physical modeling and experimental validation of core-shell nanoparticle fabrication of nickel-titanium (nitinol) alloy. Vinod Parmar, S Singh, Sunil Kumar, G Prakash, and D Kalyanasundaram Optics and Laser Technology 138, 106880 (2021). Link
• Optical and Terahertz Response of Carbon Nanostructures. Arvind Singh and Sunil Kumar Asian Journal of Physics 30(4), 633-654 (2021). Link Preprint at https://arxiv.org/abs/2104.06122
• Compact and efficient polarization splitter based on dual core microstructured fiber for THz photonics. Vikas Kumar, RK Varshney, and Sunil Kumar Results in Optics 4, 100094 (2021). Link
• Role of H-bond along with oxygen and zinc vacancies in the enhancement of ferromagnetic behavior of ZnO films: an experimental and first principle-based study. Preetam Singh, V Mishra, S Barman, SR Barman, M Balal, S R Barma, A Singh, Sunil Kumar, R Ramachandran, P Srivastava, and S Ghosh Journal of Alloys and Compounds 889,161663 (2021). Link
• Tuning of ferromagnetic behavior of GaN films by N ion implantation: an experimental and first principle-based study. Preetam Singh, S Ghosh, V Mishra, S Barman, SR Barman, A Singh, Sunil Kumar, Z Li, U Kentsch, P Srivastava Journal of Magnetism and Magnetic Materials 523, 167630 (2021). Link
• Study of Eutectic Etching Process for Defects Analysis in n-type 4H-SiC. Pooja Pal, Sunil Kumar and S.K. Singh Defense Science Journal 70(5), 515 (2020). Link
• Defect mediated modification of structural, optical and magnetic properties of Xe3+ ions irradiated GaN/sapphire films. Preetam Singh, S Ghosh, A Singh, Sunil Kumar, S Ojha, P Srivastava Nuc. Inst. Meth. Phys. Res. B 466, 61 (2020). Link
• Lead-Free Two-Dimensional (R-NH3)2MX4 Inorganic-Organic Hybrids: Solid-Solid Phase Transitions
and Broadband Emission.
Madhu Bochalya and Sunil Kumar
Journal of Physics D: Applied Physics 53, 444002 (2020).
Link
• Magnetic field-dependent resistance crossover and anomalous magnetoresistance in topological insulator Bi2Te3. Anand Nivedan, K Das, S Kumar, A Singh, S Mardanya, A Agarwal and Sunil Kumar Journal of Physics: Condensed Matter 32, 425002 (2020). Link
• Photo-Seebeck effect in single-crystalline bismuth telluride topological insulator. Anand Nivedan, A Singh, S Kumar and Sunil Kumar Applied Physics Letters 116, 141902 (2020). Link
• Design of a compact and broadband THz polarization splitter based on gradient dual core photonic crystal fiber. Vikas Kumar, RK Varshney and Sunil Kumar Applied Optics 59(7), 1974 (2020). Link
• Magnetocaloric Effect in Alkylammonium Copper Halides Layered Inorganic-Organic Systems. Madhu Bochalya and Sunil Kumar Journal of Applied Physics 127(5), 055501 (2020). Link
• Terahertz Generation by Four-Wave Mixing and Guidance in Diatomic Teflon Photonic Crystal Fibers. Vikas Kumar, RK Varshney and Sunil Kumar Optics Communications 454, 124460 (2020). Link
• Impurity assisted hopping-conduction and persistent-photoconductivity in disordered carbon nanoparticle film. Arvind Singh, A. Nivedan, S. Kumar, and Sunil Kumar Journal of Applied Physics 126(22), 225102 (2019). Link
• Structural and optical diversity in copper halide-based ferromagnetic inorganic-organic layered hybrids. Madhu Bochalya, P. Kanaujia, G.V. Prakash, and Sunil Kumar J. Solid State Chem. 273, 219-225 (2019). Link
• Magnetism and phase segregation in two-dimensional inorganic-organic (C12H25NH3)2Cu1-yMnyCl4 hybrids. Madhu Bochalya, G.V. Prakash, and Sunil Kumar J. Solid State Chem. 273, 32-36 (2019). Link
• Self-functionalized ultrastable water suspension of luminescent carbon quantum dots. Arvind Singh, P. Mahapatra, D. Kalyanasundaram, and Sunil Kumar Materials Chemistry and Physics 225, 23-27 (2019). Link
• Coherent centres for light amplification in coupled waveguide arrays. A. Tripathi and Sunil Kumar Optics Communications 418, 16–21 (2018). Link
• Coherently enhanced chirp CARS microscopy by notch filtering. L. Ren, H. Frostig, Sunil Kumar, I. Hurwitz and Yaron Silberberg Optics Express 25(23), 28201 (2017). Link
• Single-pulse CARS based multimodal nonlinear optical microscope for bioimaging. Sunil Kumar, T. Kamali, J.M. Levitte, Ori Katz, B. Hermann, R. Werkmeister, B. Považay, W. Drexler, A. Unterhuber, and Yaron Silberberg Optics Express 23(10) 13082 (2015). Link
• Hybrid single source online Fourier transform coherent anti-Stokes Raman scattering / optical coherence tomography. T. Kamali, B. Považay, Sunil Kumar, Yaron Silberberg, B. Hermann, R. Werkmeister, W. Drexler, and A. Unterhuber Optics Letters 39 5709-5712 (2014). Link
• Signatures of superconducting and pseudogap phases in ultrafast transient reflectivity of Ca(Fe0.927Co0.073)2As2. Sunil Kumar, L. Harnagea, S. Wurmehl, B. Buechner, and A. K. Sood Europhysics Letters 105, 47004 (2014). Link
• Tuning ultrafast photoresponse of gold nanorods. Sunil Kumar, M. Anija, and A. K. Sood Plasmonics 8, 1477-1483 (2013). Link
• Ultrafast photoinduced enhancement of nonlinear optical response in 15-atom gold clusters on indium tin oxide conducting film. Sunil Kumar, E. S. Shibu, T. Pradeep, and A. K. Sood Optics Express 21, 8483-8492 (2013). Link
• Gap-dependent quasiparticle dynamics and coherent acoustic phonons in parent iron pnictide CaFe2As2 across spin density wave phase transition. Sunil Kumar, L. Harnagea, S. Wurmehl, B. Buchner, and A. K. Sood Journal of Physical Society of Japan 82, 044715-044723 (2013). Link
• Ultrafast quasiparticle dynamics in superconducting iron pnictide Ca(Fe0.944Co0.056)2As2. Sunil Kumar, L. Harnagea, S. Wurmehl, B. Buchner, and A. K. Sood Solid State Communication 160, 8-12 (2013). Link
• Acoustic and optical phonon dynamics from ultrafast time-resolved optical spectroscopy of superconducting Ca(Fe0.944Co0.056)2As2 iron pnictide. Sunil Kumar, L. Harnagea, S. Wurmehl, B. Buchner, and A. K. Sood Europhysics Letters 100, 57007-57012 (2012). Link
• Probing ultrafast carrier dynamics and nonlinear absorption and refraction in core-shell silicon nanowires. Sunil Kumar, M. Khorasaninejad, M. M. Adachi, K. S. Karim, S. S. Saini, A. K. Sood Pramana Journal of Physics 79, 471-481 (2012). Link
• Coherent phonons in Pyrochlore titanates A2Ti2O7 (A=Dy, Gd and Tb): a phase transition in Dy2Ti2O7 at 110 K. N. Kamaraju, Sunil Kumar, S. Saha, S. Singh, R. Suryanarayanan, A. Revcolevschi, and A.K. Sood Physical Review B 83, 134104-134109 (2011). Link
• Femtosecond photoexcited carrier dynamics in reduced graphene oxide suspensions and films. Sunil Kumar, N.Kamaraju, K. S. Vasu and A. K. Sood International Journal of Nanoscience 10, 669-673 (2010). Link
• Ultrafast dynamics of gold nanorods: Tuning between photo-bleaching and photo-induced absorption. M. Anija, Sunil Kumar, N.Kamaraju, Neha Tiwari, S.K. Kulkarni and A.K. Sood International Journal of Nanoscience 10, 687-691 (2010). Link
• Graphene analogue BCN: femtosecond nonlinear optical susceptibility and hot carrier dynamics. Sunil Kumar, N. Kamaraju, K. S. Vasu, A. Nag, A. K. Sood, and C. N. R. Rao Chemical Physics Letters 499, 152-157 (2010). Link
• Influence of two photon absorption induced free carriers on coherent polariton and phonon generation in ZnTe crystals. N. Kamaraju, Sunil Kumar, E. Freysz, and A. K. Sood Journal of Applied Physics 107, 103102-103106 (2010). Link
• Terahertz spectroscopy of single walled carbon nanotubes embedded polymer films: observation of low frequency phonons. Sunil Kumar, N. Kamaraju, B. Karthikeyan, M. Tondusson, E. Freysz, and A. K. Sood Journal of Physical Chemistry C 114, 12446-12450 (2010). Link
• Temperature-dependent chirped coherent phonon dynamics in Bi2Te3 using high intensity femtosecond laser pulses. N. Kamaraju, Sunil Kumar, and A. K. Sood Europhysics Letters 92, 47007-47012 (2010). Link
• Large-amplitude chirped coherent phonons in tellurium mediated by ultrafast photoexcited carrier diffusion. N. Kamaraju, Sunil Kumar, M. Anija, and A. K. Sood Physical Review B 82, 195202-195208 (2010). Link
• Terahertz time domain spectroscopy of low frequency vibrations of double walled carbon nanotubes. Sunil Kumar, N.Kamaraju, A. Moravsky, R. O. Loutfy, M. Tondusson, E. Freysz, and A. K. Sood European Journal of Inorganic Chemistry 2010, 4363-4366 (2010). Link
• Direct observation of low frequency confined acoustic phonons in silver nanoparticles: Terahertz time domain spectroscopy. Sunil Kumar, N. Kamaraju, B. Karthikeyan, M. Tondusson, E. Freysz, and A. K. Sood Journal of Chemical Physics 133, 014502-014506 (2010). Link
• Ultrafast switching time and third order nonlinear coefficients of microwave treated single walled carbon nanotube suspensions. N. Kamaraju, Sunil Kumar, B. Karthikeyan, B. Kakade, V. K. Pillai, and A. K. Sood Journal of Nanoscience and Nanotechnology 9, 5550-5554 (2009). Link
• Femtosecond carrier dynamics and saturable absorption in graphene suspensions. Sunil Kumar, M. Anija, N. Kamaraju, K. S. Vasu, K.S. Subramanyam, A. K. Sood and C. N. R. Rao Applied Physics Letters 95, 191911-191913 (2009). Link
• Double walled carbon nanotubes as ultrafast optical switches. N. Kamaraju, Sunil Kumar, Y. A. Kim, T. Hayashi, H. Muramatsu, M. Endo, and A. K. Sood Applied Physics Letters 95, 081106-081108 (2009). Link
• Ultrafast electron dynamics and cubic optical nonlinearity of free standing thin film of double walled carbon nanotubes. N. Kamaraju, Sunil Kumar, B. Karthikeyan, A. Moravsky, R. O. Lutfy, and A. K. Sood Applied Physics Letters 93, 091903-091905 (2008). Link
• Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond Z-scan measurements. N. Kamaraju, Sunil Kumar, A. K. Sood, S. Guha, S. Krishnamurthy, and C. N. R. Rao Applied Physics Letters 91, 251103-251105 (2007). Link
Books/Book Chapters
• Photonic Crystal Fibers for THz Applications.
Vikas Kumar, H Mondal and Sunil Kumar
Photonic Crystal Fibers (PCFs) - Advances in Research and Applications, pp 137-182 (2024), (Nova Science Publishers, Inc. New York).
https://doi.org/10.52305/PWCW7505
• Ultrafast response of plasmonic nanostructures.
Sunil Kumar and A. K. Sood
Reviews in Plasmonics 2015, pp 131-167 (2016), (Springer International Publishing, AG Switzerland).
https://doi.org/10.1007/978-3-319-24606-2_6
Recent Conference Proceedings
• Ultrafast spintronic THz emitters and their optical damage limit. Sandeep Kumar and Sunil Kumar 2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz). https://doi.org/10.1109/IRMMW-THz50927.2022.9896052
• Ultrafast Charge Transfer and p-Plasmon Dynamics in Single-Walled Carbon Nanotubes. Arvind Singh and Sunil Kumar CLEO: Science and Innovations 2021. https://doi.org/10.1364/CLEO_AT.2021.JTh3A.56
• Two interpenetrating hexagonal lattice in clad photonic crystal fiber for THz sensing. Vikas Kumar, RK Varshney, Sunil Kumar 2020 Frontiers in Optics / Laser Science. https://doi.org/10.1364/FIO.2020.FM7B.5
• Ultrafast, broadband and tunable THz reflector based on high resistivity silicon. Sunil Kumar, S. Kumar, A. Nivedan, A. Singh, M. Tondusson, J. Degert, E. Abraham, V. Freysz, E. Freysz IRMMW-THz, 2020 45th International Conference on Infrared and Millimeter Waves. https://doi.org/10.1109/IRMMW-THz46771.2020.93709503
• THz conductivity and photo-induced carrier dynamics in a graphene, MoS2, graphene heterostructure. Sunil Kumar, A. Singh, A. Nivedan, S. Kumar, M. Tondusson, J. Degert, J. Oberle, S. J. Yun, Y. H. Lee, E. Freysz IRMMW-THz, 2020 45th International Conference on Infrared and Millimeter Waves. https://doi.org/10.1109/IRMMW-THz46771.2020.93708624
• Enhanced transient THz response in TMDC heterostructures. Sunil Kumar, A. Singh, A. Nivedan, S. Kumar, M. Tondusson, J. Degert, J. Oberle, S. J. Yun, Y. H. Lee, E. Freysz IRMMW-THz, 2020 45th International Conference on Infrared and Millimeter Waves. https://doi.org/10.1109/IRMMW-THz46771.2020.9370975
• Nonlinear Interaction of Polarization Singular Beams. Baby Komal, P Senthilkumaran, Sunil Kumar ICOL-2019, Springer Proceedings in Physics 258. https://doi.org/10.1007/978-981-15-9259-1_44
• Near Zero Flat Dispersion by Hexagonal Patterned Unit Cell in THz Photonic Crystal Fiber. Vikas Kumar, R. K. Varshney, Sunil Kumar ICOL-2019, Springer Proceedings in Physics 258. https://doi.org/10.1007/978-981-15-9259-1_203
• Broadband and flat THz dispersion in biatomic photonic band gap fibers. Vikas Kumar, R. K. Varshney, Sunil Kumar Workshop on Recent Advances in Photonics (WRAP) (2019). https://doi.org/10.1109/WRAP47485.2019.9013698
• Structural Phase Transitions and Thermal Stability in Cu-Based 2D Inorganic-Organic Hybrid Perovskite Systems. M Bochalya, PK Kanaujia, G Prakash, Sunil Kumar AIP Conference Proceedings 2142, 030001 (2019). https://doi.org/10.1063/1.5122329
• Terahertz Supercontinuum in the Biatomic Photonic Crystal Fiber. V Kumar, RK Varshney, Sunil Kumar Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) (2019). https://doi.org/10.1109/CLEOE-EQEC.2019.8872721
• On the Development of Intense THz sources for nonlinear optics and spectroscopy. Sunil Kumar IEEE 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC) (2019). https://doi.org/10.23919/URSIAP-RASC.2019.8738176
• Magnetic Phase Transition in Layered Hybrid Perovskite (C12H25NH3)2CuCl4. Madhu Bochalya, Sunil Kumar, PK Kanaujia, G Prakash AIP Conference Proceedings 1953, 120022 (2018). https://doi.org/10.1063/1.5033087