Ritika Malik Email & Phone Number

Hauzkhas

The space-bandwidth product is taken as an information measure for the optical system. One way to increase the information capacity of the system is to increase its bandwidth, which leads to all the super-resolution microscopic techniques. Another way is to increase the spatial part, which leads to a large field of view system. We are working with the later class to increase the information capacity of the system. We increase the field of view of the system with a special design of the point spread function (PSF) of the system. We are also developing the algorithm to reconstruct the large field of view image from the collected data with the designed PSF.

Unsupervised organisation of cervical cells using digital holography microscopy.Digital Holographic Microscopy (DHM) is an interferometric imaging technology that provides quantitative phase information. The phase function contains information on optical path length (a product of refractive index and thickness) through the cell sample. By using unsupervised machine learning algorithms (PCA, Kernel PCA, Gaussian Mixture Model), it is possible to separate cancerous cells from normal cells on a 2D plot of the first two principal components.In this project, we collect data on different types of cells using the DHM system. We extract parametric information using the brightfield images as well as using quantitative phase values. We apply PCA to parameters to separate normal and cancerous cells.

Design of meta-surface structure for bending light in desired direction.Metasurface are sub-wavelength-sized structured elements arranged such that they impart the desired phase to the incident light, which then leads to the bending of light in desired direction. Properly designed metasurface help in various application such as flat optical lens, super-resolution, optical cloaking etc.In this project we did simulation studies using MaxwellFDFD tool to designed gradient metasurface structure which have the ability to focus light and therefore shows a behaviour of flat lens. We were also able to calculate the approximate value of the angle at which light bends using effective medium theory.

Statisticsal studies of radio pulsar’s glitches.Neutron stars are one of the most extreme and exciting nuclear physics laboratories in the universe, with a mass slightly above that of the sun, compressed into a radius of 10 km. Radio pulsars are the rotating magnetized neutron star. Their huge moment of inertia (10^45 gcm2) leads to exceptionally stable rotation rates and provides us with the with the most stable clock of the universe. Radio pulsars exhibit several timing irregularities, the most striking of which are so-called glitches. Pulsars are observed to slow down due to continuous emission of electromagnetic radiation but this continuous slowdown breaks at the time of glitches. Glitches are sudden spin-ups in the normal slowdown rate of pulsars and their observation in pulsars helps in probing interior of Neutron stars.In this project, we were trying to find a systematic relationship (if any) between glitch size and pre- and post-glitch size using glitch data from Jodrell Bank Telescope. We hadnot seen any standard repetitive trends in plots of glitch size versus pre- and post-glitch time, and no type of trends are seen for the consecutive glitches.

Doctor Of Philosophy - Phd, Information Efficient Computational Imaging System

Activities and Societies: SPIE, OSA, IIT Delhi Student Optica Chapter* Dissertation Title: "Information Efficient Computational Imaging.

Doctor Of Philosophy - Phd, Computational Imaging

Master Of Science, Physics, Cgpa : 9.3

• M.Sc. Project: "Design of meta-surface structure for bending light in the desired direction." • Worked during the semester as a VSRP.

Bachelor Of Science