Photonics Group of IITD

The Department of Physics, IIT Delhi has a rich history in optics and photonics research that goes way back to the late 1960s. Initially what started as a very small group of about ten people, has over the years, and has flourished in terms of both research activity and manpower. Today
there are Inore than one hundred people in the departnnent including faculty members, researchers and graduate students, working actively in numerous branches of optics and across disciplines.
Initially, the research work was focused on optical interferometry, image processing, and holography; in parallel, research work was initiated in modelling and study of propagation characteristics of multimode and single-mode optical fibers and integrated optical waveguides. The department had its first Fiber Optics Laboratory set up in 1980 with an aim of studying and developing various fiber characterization techniques. The laboratory has since thrived, and at present it is equipped with various state of the art lasers and fibers test and measurement instruments. The major activities undertaken in the laboratory include fabrication and characterization of fused fiber and side-polished fiber couplers and related components, study of Er-doped fiber amplifiers, fiber Bragg gratings, fiber optic chemical sensors and nonlinear interactions in lithium niobate waveguides.

Currently, there are several sub-groups working on theoretical and experimental guided wave optics, holographic techniques, high-resolution imaging, ultrafast optics, laser spectroscopy, liquid crystal photonics, and quantum optics. The Department is developing new research laboratories with the goal of functioning in contemporary areas of Photonics. These laboratories are well equipped with computational infrastructures and advanced instruments. The Quantum Photonics group focusses
on the generation of entangled photon pairs in PPLN ridge waveguide using parametric down conversion process and four wave mixing in silicon nano-waveguides to generate broadband photons in the telecom band. Experimental quantum interferometry and polarization (EQUIP)
team works in the area of ultrafast quantum and non-linear optics, optical coherence, polarization, interferometry, tomography, spectral switching and plasmonics. Femtosecond Laser Spectroscopy group is actively engaged in exploring the nature of light-matter interaction at ultrafast time scales
by using the femtosecond laser pulses and working in the field of Terahertz (THz) spectroscopy, Nonlinear optical spectroscopy and bio-imaging. The Liquid Crystal research group has recently developed a number of sophisticated liquid crystal based optical waveguides, optical switches and power splitters. They are also actively engaged in characterizing different liquid crystalline (LC) systems, tailoring of LC properties by nano-doping, fabrication of polymer dispersed LCs and sensors.

Laser spectroscopy group works in the field of laser-matter interaction, pulsed laser ablation and stilface enhanced Raman spectroscopy based molecular detection of different analyte molecules.
The experimental Photonics group works on fabrication of complex photonic crystals using interference lithography, high sensitivity guided mode resonance (GMR) optical sensors and super-resolution microscopy using structure illumination microscope (SIM). The Photonics research
laboratory is also engaged in research on computational imaging with emphasis on methodology for image reconstruction from incomplete data and robust beam engineering. The applied optics and bio-photonics group focuses on face reconstruction of biological samples like RBCs and cancer cells, solid state lighting (LEDs, OLEDs), optical coherence tomography (OCT) and optical tweezers. Singular Optics group is working on singular optics, orbital angular momentum, polarization singularities, energy flows, generation of various lattice patterns and optical vertex beams or optical vortices.

Recently, an Ultrafast optics (UFO) laboratory has been established in the Department, and presently it houses several modern day optical instruments ranging from a femtosecond laser to
a Raman spectroscope, optical microscopes etc. The department also offers central facilities for optical measurements and has benefitted largely by the recent inclusion of world-class fabrication and clean-room facilities at the NRF, IIT Delhi. Collaborative and independent research in the depaftment are funded by various national and international sources such as DS T, DRDO, CSIR, IFCPAR, UKIERI and many more. The department also has academic and research collaborations with leading institutions in the country and across the globe.

Contributions to education, research and development in the area of Optics and Photonics made by the faculty and students of the Physics department, IIT Delhi have brought recognition to the faculty in terms of various fellowships and awards.