Khokan Roy

Background

About Khokan Roy

Self-motivated and fast-learning optical scientist in single-molecule spectroscopy, microscopy & nonlinear imaging with 11+ years of hands-on experience in various optical measurement techniques (stimulated Raman, femtosecond transient absorption, tip-enhanced Raman, surface-enhanced Raman, coherent anti-Stokes Raman, & 2nd & 3rd order vibrational sum-frequency imaging, etc.). • Multi-disciplinary team player with 11+ years of hands-on experience in designing, assembling, aligning, testing, troubleshooting, and integrating breadboards to demonstrate the feasibility of optical measurement setup. • Strong 2D image processing, and data analysis skills using Matlab & ImageJ software. • Working experience with Adaptive optics & imaging (automatic laser power controller, plasmonic focus control, etc). • Skilled in optical alignment methodologies and equipment. • Skilled in instrumentation, control software, electronics, optical test methodologies, and equipment. Doctoral Research: • Designing experimental setup for stimulated Raman scattering and femtosecond transient absorption spectroscopy. • Measurement of excited-state Raman from organic molecules. • High-level problem-solving skills exemplified through performing routine and complex functions to ensure high performance and reliability of the optical instruments. • Working experience with biomolecules, and small organic materials important for optoelectronics. Post-Doctoral Research: • Vibrational sum-frequency imaging of micron-size collagen fiber using a multiphoton scheme. • Anti-Stokes coherent Raman sensing of single-molecule at metal-dielectric and dielectric-dielectric interfaces with minimum illumination dosage reported so far. • Single-molecule imaging in ultra-high vacuum conditions using tip-enhanced Raman scattering. • Optimization of experimental parameters (voltage, junction gap, current, etc.) in Matlab for single-molecule imaging. Additional skills (Instruments handle): Raman microscopy, STM, PVD, oscilloscope, auto-correlator, photodiode, mode-locked laser, laser amplifier, PMT, function generator, lock-in amplifier, photon counter, cryogenic transfer, optical microscope, etc. Software and programming skills: • Matlab (advance), LabVIEW (basic), Fiji/ImageJ, Latex, Zemax (beginner). • Numerical modeling & global analysis of hyperspectral data.