Physics Theory Seminar with Pratik Barge on Imaging with small number of photons using quadrature-noise measurement

Imaging is normally performed using bright probe light with detected intensities in the range of 103 – 105 photons per pixel. However, fragile samples like biological specimens, photosensitive chemicals might require operation at much lower illumination levels. At these levels, sensitivity of the traditional imaging schemes is severely affected by various sources of noise. In the first part of my talk, I will introduce our novel method, Quadrature-Noise Shadow Imaging (QSI), for low-light imaging that utilizes the changes in the quadrature-noise statistics of the probe beam after its interaction with an object. QSI can be accomplished with both, classical (thermal state) as well as non-classical (squeezed state) sources and has an advantage over the classical differential imaging when the effect of noise is considered. In the second part of the talk, I will discuss our work on single-pixel imaging and use of compressed sampling, a signal recovery algorithm, to reduce the number of measurements required to obtain an image.