Interferometric phase stability from Gaussian and space–time light sheets

Abstract

The incredible phase sensitivity of Michelson interferometry has made it useful for a variety of metrology and sensing applications with the trade-off that it is also vulnerable to unwanted fluctuations in the sensing environment. Here, we demonstrate that Michelson interferometry using either Gaussian or space–time (ST) light sheets results in enhanced passive phase stability. Our experiments are absent of any active damping techniques. When using the ST light sheet, the interferometer exhibits 23% higher phase stability compared to the Gaussian light sheet (GLS), and 80% higher stability when compared to the Gaussian beam (GB). We find that while both ST light sheet and GLS exhibit significantly higher phase stability than the GB, ST light sheets have the added advantage of being resistant to speckle generation when a thin diffuser is inserted in the interferometer. Additionally, we show that interferometry using the ST light sheet results in approximately 11× more accurate measure of an oxide thickness on the substrate than the Gaussian beam. Our findings provide a simple approach to improving the stability of optical interferometry for applications, such as high-precision length measurements, enhanced sensing, and quantum optical experiments.