Research

Ph.D.

Thesis Title: “Studies on linear and nonlinear propagation effects in Bragg reflection waveguides”

Institute/College: Department of Physics, Indian Institute of Technology Delhi, India

Projects:

1) Analysis of Bragg reflection waveguides which includes studies on phase and group velocity dispersion characteristics, design criteria for realization of linear and nonlinear optical processes.

2) Utilizing the dispersion properties of Bragg reflection waveguides for tailoring the frequency bandwidth of interaction for various quasi phase-matched second order nonlinear processes such as second harmonic generation, optical parametric amplification, difference frequency generation and spontaneous parametric downconversion. The proposed designs and schemes could be used for generating broadband pulses in visible, near-infrared and mid-infrared.

3) Analysis of Bragg reflection waveguides for the realization of efficient modal phase-matching schemes in second order nonlinear optical process.

4) Studies and analysis of two-dimensional photonic crystals using plane-wave expansion method from the perspective of realization of filters and modulators.

5) Studies of high index core photonic crystal fibers (PCFs) using effective index method.

For carrying out the studies, I have extensively used MATLAB 6.5, 7.0, 7.1, Mathematica and RSoft CAD Layout (Bandsolve, FemSim, FullWave).

I have carried out some part of the above-mentioned research work in close collaboration with researchers from Center for Advanced Research in Electronics (CARE), I.I.T. Delhi and Laboratoire de Physique de la Matière Condensée, Université de Nice, Sophia-Antipolis, France. More details on the research work could be found in the list of publications.

Postdoctoral Research:

Title of Research: Development of a new generation of high power and tunable coherent light sources for applications in biophotonics, biomedicine and laser surgery

Institute/Lab: ICFO-The Institute of Photonic Sciences, Barcelona, Spain

Projects:

1) Generation of high power (~ 10.0 W and above), single-pass green source (532 nm) from a 30.0 W continuous-wave Yb-fiber laser in periodically poled stoichiometric lithium tantalate crystals.

2) Generation of continuous-wave, high power (Watt level), single frequency and highly stable waves in the near and mid-infrared region of the spectrum from lithium niobate, lithium tantalate, Cadmium silicon phosphide based optical parametric oscillators (OPO) pumped by a 30.0 W single frequency fiber laser.

3) Use of multi-stage second harmonic generation and optical parametric oscillator configurations for efficiency enhancement and thermal load redistribution.

4) Experimental realization and spectral characterization of Ti:Sapphire laser pumped by a frequency doubled 30.0 W fiber laser.

Analysis of modes and mode-coupling in structures comprising extremely thin metal films (few tens of nanometer thickness) and planar Bragg structures.