Engineered wavefronts for imaging applications: From conventional to metasurface optics.

Wavefront modulation has found use in many applications including optical manipulation in the micro-regime, optical communications, photolithography and imaging, among others. Traditionally, wavefront engineering is implemented by conventional optical components that are based on refraction or diffraction, as light propagates through these components. With the advent of computing, and micro and nanofabrication technologies, a new class of optical components has started to emerge. Metasurface optics rely on nanoscale light-matter interactions to control the wavefront of an incident light, promising new capabilities that could only be achieved previously with a combination of bulky conventional optics. This thesis explores imaging applications of engineered wavefronts, modulated using both conventional and metasurface optics. For the first application, a refractive element is employed to construct a common-path interferometer for use in determining the topological charge of beams with orbital angular momentum. Secondly, a commercial optical vortex produced using birefringent liquid crystals is utilized for high-contrast non-linear imaging. Finally, a multifunctional metasurface device is exploited to facilitate single-shot quantitative phase imaging and is applied for wavefront sensing.