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  • 9:09 AM, Tuesday, 20 Oct 2020

Department of Physics
     
Ashok Kumar, Ph.D.
Assistant Professor
 
Office
Tel:+91-471-2568662
Fax:
Email:ashokkumar@iist.ac.in / phy.ashok@gmail.com













Education

Ph.D. (Physics), Physical Research Laboratory, Ahmedabad, India

M.Sc. (Physics), Kumaun University, Nainital, India

B.Sc. (Physics, Chemistry, Mathematics), Kumaun University, Nainital, India


Experience

08/2015– 01/2019: Post-Doctoral Research Associate, The University of Oklahoma, Norman, USA

02/2013– 07/2015: Post-Doctoral Fellow, University of Sao Paulo, Sao Paulo, Brazil

12/2011-01/2013: Post-Doctoral Fellow, Physical Research Laboratory, Ahmedabad, India


Research Work / Area

Experimental Quantum Optics, Quantum Sensing, Quantum-Enhanced Imaging, Quantum Plasmonic Sensors, Bright Squeezed States, Electromagnetically Induced Transparency, Orbital Angular Momentum of Light.

Reviewing work

I have been a referee for Nature Physics, Optics Letters, Optics Express, Journal of Modern Optics, Journal of Optical Society of America A, and Optics and Lasers in Engineering

 

 Journal Publications:

1. Ashok Kumar, and A. M. Marino, Spatial Squeezing in bright twin beams generated with four-wave mixing: constraints on characterization with an electron-multiplying charge-coupled-device camera, Physical Review A 100, 063828 (2019).

2. M. Dowran, Ashok Kumar, B. J. Lawrie, R. C. Pooser, and A. M. Marino, Quantum plasmonic sensing beyond the classical limit, Optics and Photonics News 29, 54 (2018).

3. M. Dowran, Ashok Kumar, B. J. Lawrie, R. C. Pooser, and A. M. Marino, Quantum-enhanced plasmonic sensing, Optica 5, 628 (2018).

4. Ashok Kumar, H. Nunley, and A. M. Marino, Comparison of coherence area measurement techniques for bright entangled twin beams, Physical Review A 98, 043853 (2018).

5. K. Theophilo, Ashok Kumar, H. M. Florez, C. Gonzalez, P. Nussenzveig, and M. Martinelli, Probing light forces on cold atoms by noise correlation spectroscopy, Physical Review A 98, 053832 (2018).

6Ashok Kumar, H. Nunley, and A. M. Marino, Observation of spatial quantum correlations in the macroscopic regime, Physical Review A 95, 053849 (2017).

7. H. M. Florez, Ashok Kumar, K. Theophilo, P. Nussenzveig, and M. Martinelli, Correlation spectroscopy in cold atoms: light sidebands resonances in electromagnetically induced transparency condition, Physical Review A 94, 012504 (2016).

8. P. Kalauni, Ashok Kumar, and J. C. A. Barata, Generalization of coherent state quantization in higher dimensional de Sitter space, Physical Review D 92, 124032 (2015).

9. Jitendra Bhatt, Ashok Kumar, R. P. Singh, and S. N. A. Jaaffrey, Optical trapping of fluorescence beads, Journal of Experimental Nano Science 10, 290 (2015).

10. Shashi Prabhakar, Salla Gangi Reddy, A. Aadhi, Ashok Kumar, P. Chithrabhanu, G. K. Samanta, and R. P. Singh, Spatial distribution of Spontaneous Parametric Down-Converted Photons for higher order optical vortices, Optics Communication 326, 64 (2014).

11. Salla Gangi Reddy, Shashi Prabhakar, Ashok Kumar, J. Banerji, and R. P. Singh, Higher order optical vortices and formation of speckles, Optics Letters 39, 4364 (2014).

12. Salla Gangi Reddy, Shashi Prabhakar, Aadhi A, Ashok Kumar, Megh Shah, R. P. Singh, and R. Simon, Measuring the Mueller matrix of an arbitrary optical element with a universal SU(2) polarization gadget, Journal of Optical Society of America A 31, 610 (2014).

13. Sunita Kedia, Ashok Kumar, and R. P. Singh, Propagation of vortex beams through self-assembled photonic crystal, Journal of Experimental Nano Science 8, 249 (2013).

14. Pravin Vaity, Ashok Kumar, and R. P. Singh, Manifestation of coherence decay of optical vortices on scattering through photorefractive SBN crystal, Journal of Optics (IOP) 15, 025711 (2013).

15. Salla Gangi Reddy, Ashok Kumar, Shashi Prabhakar, and R. P. Singh, Experimental generation of ring shaped beams with random sources, Optics Letters 38, 4441 (2013).

16. Ashok Kumar, Pravin Vaity, Jitendra Bhatt, and R. P. Singh, Stability of higher order optical vortices produced by spatial light modulator, Journal of Modern Optics 60, 16961700 (2013).

17. Sunita Kedia, Ashok Kumar, and R. P. Singh, Investigation of local structural properties of self-assembled photonic crystals by optical diffraction, Applied Physics B 108, 903 (2012). 

18. Jitendra Bhatt, Ashok Kumar, and R. P. Singh, Controlling the flow of microscopic particles-the role of beam size, Optics and Photonics Journal 2, 294 (2012).

19. Ashok Kumar, J. Banerji, and R. P. Singh, Hanbury Brown and Twiss- type experiments with optical vortices and observation of modulated intensity correlation on scattering from rotating ground glass, Physical Review A 86, 013825 (2012).

20Ashok Kumar and R. P. Singh, Photon correlation spectroscopy: A comparative study of optical vortex and Gaussian beam, Asian Journal of Physics 20, 251 (2011).

21. Shashi Prabhakar, Ashok Kumar, J. Banerji, and R. P. Singh, Revealing the order of the vortex through its Intensity Record, Optics Letters 36, 4398 (2011).

22. Ashok Kumar and R. P. Singh, Experimental and theoretical investigation of loss of coherence on scattering of a beam with helical wavefront, Optics Communication 284, 1510 (2011).

23. Ashok Kumar, Pravin Vaity, J. Banerji, and R. P. Singh, Making optical vortex and its copies using a single spatial light modulator, Physics Letters A 375, 3634 (2011).

24. Ashok Kumar, Pravin Vaity, and R. P. Singh, Crafting the core asymmetry to lift the degeneracy of optical vortices, Optics Express 19, 6182 (2011).

25. Ashok Kumar, Shashi Prabhakar, Pravin Vaity, and R. P. Singh, Information content of optical vortex field, Optics Letters 36, 1161 (2011). 

26. Ashok Kumar, Pravin Vaity, Yedhu Krishna, and R. P. Singh, Engineering the size of dark core of an optical vortex, Optics and Lasers in Engineering 48, 276 (2010).

27. Ashok Kumar, Pravin Vaity, and R. P. Singh, Diffraction characteristics of an optical vortex passing through an aperture-Iris Diaphragm, Optics Communication 283, 4141 (2010).

28. Ashok Kumar, J. Banerji, and R. P. Singh, Intensity correlation properties of high-order optical vortices passing through a rotating ground glass plate, Optics Letters 35, 3841 (2010).


Book Chapters:


1. R. P. Singh, Ashok Kumar, and Jitendra Bhatt, Vortices of Light: Generation, Characterization and Applications, Progress in Nonlinear Optics Research, eds. Takahasi, M., Goto, H., Nova Science, pp. 359-381 (2008).


For more information about my publications, please visit:

https://scholar.google.co.in/citations?user=ZnZbJJoAAAAJ&hl=en

International visits and talks given

2017: Center for Nanophase and Material Science, Oak Ridge National Laboratory, Oak Ridge, USA: Title- Quantum-Enhanced Plasmonic Sensors

2015: Department of Physics, University of Pernambuco, Recife, Brazil: Title- Investigation of laser beams carrying orbital angular momentum

2013: Institute of Physics, University of Sao Paulo, Brazil: Title- A study of twisted light beams

2012: Institute for Ultrafast Spectroscopy and Lasers, City College of New York, USA: Title- A study of coherence properties of optical vortices

2012: Electrical and Computer Engineering Department, Boston University, USA: Title- A study of propagation, diffraction and coherence properties of optical vortices

2012: Institute of Photonic Sciences, Barcelona, Spain: Title- Field and intensity correlation studies of optical vortices

2011: Quantum Optics Group, University of Rome, Italy: Title- Vortices in light: field and intensity correlation studies

2011: Instituto Nazionale di Ricerca Metrologica INRIM, Turin, Italy: Title-Vortices in light: field and intensity correlation studies

Conference participations and paper presentation

 2018: 49th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Ft. Lauderdale, Florida, USA: Paper-Direct measurement of position-momentum entanglement in bright twin beams

2018: CLEO:2018, San Jose convention center, San Jose, USA: Paper-Quantum-Enhanced Ultrasound Detection with Plasmonic Sensors

2016: Frontiers in Optics, Rochester, USA: Paper-Spatial Squeezing in Bright Twin Light Beams using a CCD Camera

2016: 47th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Providence, Rhode Island, USA: Paper-Experimental observation of spatial quantum noise reduction below the standard quantum limit with bright twin beams of light

2014: International Conference on Atomic Physics, Washington DC, USA: Paper-Non-Resonant correlation spectroscopy in cold atoms: extracting the correlation information of light sidebands

2013: Symposium honoring Prof. Daniel Kleppner, Sao Carlos, Brazil: Paper-Intensity correlation studies of optical vortices

2012: CLEO:2012, San Jose convention center, San Jose, USA: Paper-HBT-type experiment with optical vortices

2012: National Laser Symposium-20, Anna University Chennai, India: Papers-(i) Experimental analysis of optical diffraction in self-assembled photonic crystals, and (ii) First and second order coherence studies of optical vortices

2012: 99th Indian Science Congress, KIIT Bhubaneswar, India: Paper-Making optical vortex and its copies using a single spatial light modulator

2011: Workshop and Singular Optics and its Applications to Modern Physics, ICTP, Trieste, Italy: Paper- An experimental investigation of spatial coherence and information entropy of optical vortices

2011: XXXV OSI Symposium-International Conference on Contemporary Trends in Optics and Optoelectronics, IIST Thiruvananthapuram, India: Paper-Degeneracy of optical vortices and the core asymmetry

2010: International Conference on Fiber Optics and Photonics, IIT Guwahati, India: Papers- (i) Decoherence of optical vortices in scattering, and (ii) Two-point correlation function for optical vortices

2010: State Level Conference on Role of Science and Technology in the Development of Uttarakhand State, GPGC Bageshwar (India): Paper-Ellipticity of the core and decay of high order optical vortices

2010: National Laser Symposium-09, BARC Mumbai, India: Paper-Experimental study of power decay of optical vortices in photorefractive material

2010: International Conference on Fiber Optics and Photonics, IIT Delhi, India: Paper-Photon Correlation Spectroscopy using Optical Vortices

2009: Workshop on Introduction to Optofluidics, ICTP, Trieste, Italy: Paper-Controlling the flow of microscopic particles using optical beams

2008: Workshop on Laser Spectroscopy and Nano Photonics, IIT Delhi, India: Paper-Optical trapping and fluorescence studies of microscopic particles

 

 

 

 

My current research interests are in different areas of experimental quantum optics and quantum technologies. In particular, currently I am interested in generation of bright quantum light (or bright twin beams) with a four-wave mixing process in an atomic medium, and then its use in various quantum protocols and quantum metrology applications.