This thesis discusses the development of a heterodyne based system designed to detect the coherent component of light transmitted through a turbid medium. The system can detect coherent light intensity as low as 100 dB of an initial sub-milliwatt level input beam. It employs a very narrow bandwidth approach for generating the required heterodyne signal so that the bandwidth of the detection is ...

Coherence in light-matter interaction is a necessary ingredient if light is used to control the quantum state of a material system. Coherent effects are firmly associated with isolated systems kept at low temperature. The exceedingly fast dephasing in condensed matter environments, in particular at elevated temperatures, may well erase all coherent information in the material at timescales shor...

Coherent light-matter interaction in ultrathin metamaterials has been demonstrated to dynamically modulate intensity, polarization and propagation direction of light. The gradient metasurface with a transverse phase variation usually exhibits an anomalous refracted beam of light dictated by so-called generalized Snell's law. However, less attention has been paid to coherent control of the metas...

Speckle in optical coherence tomography (OCT) images originates in the high spatial coherence of incident light that enables interference of light backscattered from spatially heterogenous tissue specimens. We report results of a numerical simulation and an experiment to test speckle reduction using a partially spatially coherent source. A Gaussian-Schell model for a partially spatially coheren...

Ultrafast phonon dynamics in anatase and rutile TiO2 single crystals are investigated using 400 nm near ultraviolet light pulses, whose wavelength corresponds to the fundamental absorption edges of both polymorphs. Raman-active phonon modes are observed as coherent modulations in THz frequency range of the reflected light intensity. Coherent amplitudes vary as the crystals are rotated with resp...

Generation of arbitrary superposition of vacuum and one-photon states using quantum scissors device (QSD) is studied. The device allows the preparation of states by truncating an input coherent light. Optimum values of the intensity of the coherent light for the generation of any desired state using the experimentally feasible QSD scheme are found.

We introduce an active, all-optical method for controlling the intensity and directionality of light scattering from single nanostructures. The method is based on the coherent interplay between linear light scattering and second-harmonic generation. The intensity and directionality of scattered light can be controlled by the phase delay and the relative angle between excitation beams. We discus...

We have observed spatial confinement of laser light in micrometer-sized random media. The optical confinement is attributed to the disorder-induced scattering and interference. Our experimental data suggest that coherent amplification of the scattered light enhances the interference effect and helps the spatial confinement. Using the finite-difference time-domain method, we simulate lasing with...

We have built an optical magnetometer based on the nonlinear Faraday effect in hot Rb vapor and probe this device with both coherent light and polarization-squeezed light. We generate the squeezed light states using the polarization self-rotation effect in Rb vapor, optimized for the highest noise suppression, giving us a system which is allatomic. By probing with polarization-squeezed states o...