Nanoscale Optical Addressing of Valley Pseudospins through Transverse Optical Spin

Valley pseudospin has emerged as a good quantum number to encode information, analogous to spin in spintronics. Two-dimensional transition metal dichalcogenides (2D TMDCs) recently attracted enormous attention for their easy access to the valley pseudospin through valley-dependent optical transitions. Different ways have been reported to read...

Optical field sampling for imaging and optical testing

This dissertation has mainly aimed at developing novel techniques, methodologies for measuring the optical field, specifically both the amplitude and phase distribution. Furthermore, we have attempted to extend their applications in the scope of optical imaging, including lensless/holographic imaging, quantitative phase imaging and the...

Shack-Hartmann reflective micro profilometer

We present a quantitative phase imaging microscope based on a Shack-Hartmann sensor, that directly reconstructs the optical path difference (OPD) in reflective mode. Comparing with the holographic or interferometric methods, the SH technique needs no reference beam in the setup, which simplifies the system. With a preregistered reference, the...

Phase retrieval from multiple binary masks generated speckle patterns

We present a reference-less and time-multiplexing phase retrieval method by making use of the digital micromirror device (DMD). In this method, the DMD functions not only as a flexible binary mask which modulates the optical field, but also as a sampling mask for measuring corresponding phases, which makes the whole setup simple and robust. The...

Lensless coherent imaging by sampling of the optical field with digital micromirror device

We have experimentally demonstrated a lensless coherent microscope based on direct registration of the complex optical field by sampling the pupil with a sequence of two-point interferometers formed by a digital micromirror device. Complete registration of the complex amplitude in the pupil of the imaging system, without any reference beam,...