Research

While my PhD research focused strongly on fundamental aspects of diffuse optics, my current research utilizes interferometric diffuse optical methods to noninvasively study cerebral blood flow and deep tissue hemodynamics. In addition, I am interested in translating lab-scale research into affordable, low-cost clinical devices.

Broadly, my research can be categorized into two groups:

Tissue optics (CW & TD-NIRS, DCS/DWS, iNIRS, iDWS): aim for practical applications
Transport in linear and nonlinear disordered media (SHG, Harmonic nanoparticles, Wavefront shaping, Speckle, Optical Microscopy): fundamental studies with possible applications

See my list of publications on ORCID | Google Scholar .

Current projects

Interferometric diffuse optics for deep tissue hemodynamics

to be updated

Relevent publications:

Optics Letters 50, 2382-2385(2025): 1060 nm interferometric near-infrared spectroscopy, D. Mazumder, S. Aparanji, O. Kholiqov, D. Hamilton, R. Samanta and V. J. Srinivasan [PDF]

Interferometric diffuse optics for mesoscopic imaging

to be updated

Past projects: during PhD

Light transport in second-order nonlinear disordered media

A scattering medium scrambles the incoming wavefront and creates a speckle pattern. In this project, we studied photon transport in scattering media composed of nonlinear scatterers, specifically second-order nonlinearity. This type of medium generates speckle patterns of both the harmonics. We explored the spatial and temporal diffusion in finite-sized nonlinear disordered media. Subsequently, we explored speckle correlation for both the harmonics.

Relevent publications:

arXiv:2504.14589 : Second-order nonlinear disordered photonic media, R. Samanta^, R. Savo^, C. Conti and S. Mujumdar (^ Equal contribution)
Phys. Rev. A 108, 053501(2023): Photon diffusion in space and time in a second-order nonlinear disordered medium, R. Samanta, R. Pierrat, R. Carminati and S. Mujumdar [PDF]
Phys. Rev. Applied 18, 054047(2022): Speckle decorrelation in fundamental and second-harmonic light scattered from nonlinear disorder, R. Samanta, R. Pierrat, R. Carminati and S. Mujumdar [PDF]
Appl. Opt. 59, 11266-11272 (2020): Intensity-dependent speckle contrast of second harmonic light in a nonlinear disordered medium, R. Samanta and S. Mujumdar. [PDF]

Controlling light transport in disordered media

In this project, we employed a Digital Micromirror Device (DMD) and Genetic algorithm to control (spatial and spectral) broadband light through linear scattering media. Subsequently, we also employed the same to control SHG light scattered from nonlinear disordered media utilizing binary wavefront optimization.

Relevent publications:

Optics Letters 48, 4241-4244(2023): Controlling the transmission of broadband light through scattering media using a Digital Micromirror Device, R. Samanta and S. Mujumdar [PDF]