High space-bandwidth wavefront sensing by sampling and spatial multiplexing.

摘要

Interferometric optical phase sensors (wavefront sensors) are used in many of today's high technology industries such as semiconductor processing and data storage. However, their vibration sensitivity and difficulty in achieving real-time detection hamper the wider use of these sensors. The sampling field sensor (SFS) has been proposed previously to solve these problems [Remy Tumbar, “Field Sampling and Shearing Wavefront Sensors,” M.S. in Electrical and Computer Engineering, Urbana, Illinois, 1998]. This work further develops the SFS concept and investigates, through numerical and experimental tests, the design of an SFS with free-space diffractive fan-out. Finally, a dramatically improved SFS design, which uses birefringent elements to do the fan-out, is described and tested.; The SFS is a breakthrough concept in wavefront sensor design. It is, to our knowledge, the first high-accuracy, high-resolution, vibration-insensitive, one-shot wavefront sensor. It achieves high accuracy by using a phase-shift shearing interferometric approach in detecting wavefront phase differences. It achieves high resolution by sampling the input wavefront and fanning out the samples to the output plane (space multiplexing), on a common optical path. The common path fan-out configuration makes the system compact and vibration-insensitive.