Ongoing Thesis

Akash Dixit	Topic: Study of optical modes in a cavity resonator Abstract: High performance optical system contains multiple resonators, in addition to beam steering optics. Unless the mode shape and dimensions of optical beams are matched to resonator mode, light beams do not resonate properly leading to loss of efficiency. This project involves design of mode-matching elements to match the laser beams and resonant cavity. The thermal effects and the stray light effects within the cavity are also responsible for distorting the optical mode and hence to study them and thereby come up with the compensation techniques.
Akash Pandey	Abstract: Aim is to design and implement fiber-optic hydrophone sensor for under water surveillance and communication. Use of coherent detection and signal processing algorithms, implemented on high speed DSP will help us in improving performance of sensor array system. Further, we will be doing parametric study of acoustic performance of the sensor array at various conditions such as water depth, acoustic pressure and environment variations.
Gaurav Sharma	Title: Characterizing Response of Laser Scanners for Archeological Materials Abstract: The present need in Archaeological surveying is to save the historical sites and places of national importance. Laser scanning plays a powerful tool to save digital imprints of all such data and preserve each nook and corner details so that in the need of reconstruction, actual measurements and traits are available. However, there is not much information regarding the criteria for selection of a particular laser scanner for a particular kind of archaeological material. Therefore, this research aims at characterizing the archaeological materials for different laser scanners and understand the interaction of lasers with these materials.
Onkar Mane	Photoluminescence study of GaSb/InAs superlattice intermixing for photodiode applications at 3-5micron wavelength. GaSb/InAs superlattice intermixing carried out by fs laser anneal is expected to change the band gap of the material to create isolation of the photodiodes as they are normally very leaky. The study is to optimize the insulation.
Rabrindra Biswas	Title:Interaction of moving magnetic mirror with radiation: A quantum formulation Abstract: Interferometry is an important tool for sensing small displacements and is widely used across a variety of disciplines. The sensitivity of a typicinterferometer is limited by shot noise, which results from the discrete particle nature of photons. To improve the sensitivity of interferometers, “squeezed” light has been proposed. These are quantum states of light with reduced quantum fluctuations. These are usually accomplished using nonlinear optical media; however, another promising possibility is optomechanical or “ponderomotive” squeezing. 1.Our objective is to analyze the physical process and the governing equations involved in such coupled field-mirror system, where magnetic mirror has been used instead of conventional metallic mirror. 2.Design and modeling of a magnetic mirror under the meta-materials domain using COMSOL.
Neha Goswami	Security of the data being transferred is one of the most important concern for the communicating parties. Quantum key distribution is a technique through which we can generate secret keys for encoding data, such that security is guaranteed. Although quantum key distribution is a hotspot of research which has led to a variety of significant improvements yet improvements in long haul fiber transmission capability, key rate and security are some of the areas which this project aims to cover. This project involves proposal of a new protocol through which long distance secure fiber based communication can be realized with the help of quantum cryptography. The protocol is based on higher order phase encoding of single photon states which leads to generation of higher alphabets per pulse leading to increase in raw key rate. The proposed scheme increases secure key generation rate as well as security parameter. To implement the scheme, this project also involves design of transmitter and receiver structures. To further increase key rate multiplexing and decoy state methods are also to be studied.
Ankita Jain	DSP algorithms to mitigate channel impairments in optical communication: The aim of this project is to develop sophisticated signal processing algorithms to mitigate several channel impairments e.g. laser phase noise, ASE noise, dispersion, nonlinear effects such as self- and cross-phase modulation, four wave mixing, and Raman scattering on the performance of several phase modulated systems viz. QPSK, PM-QPSK (Polarization Multiplexed QPSK) and 16-STAR QAM.
Raman Kumar	Electro-optic Lithium Niobate Devices Using Femtosecond Lasers 1. Fabrication and characterization of Optical Waveguides in Lithium Niobate using Femtosecond lasers. 2. Fabrication and characterization of Mach-Zehnder modulator using Femtosecond Lasers.
Nagendra Yadav	CO2 laser scanned images and/or engraving on steel. : Created a labview code that is used to control the movement of a galvanometer scanner to scan the images of strings due to which the position of a laser beam direction is controlled according to strings and resulted into engraving on a targeted surface that moves at rotational speed of about 2800 rpm.