Subsampling techniques for gaussian laser beam radius estimation using a configurable quadrant photodiode (CQD)

Gaussian laser beam diameter can be estimated using quadrant photodiodes and x-y micropositioners. The resolution of the measurement reported depends on the resolution of the micropositioners. In this article, an improvement of the resolution using subsampling estimation is reported. This technique in combination with configurable quadrant photodiodes allow to avoid the use of micropositioners, easing the design of ultra-compact laser beam displacement measurement systems avoiding mechanical elements.