What is the easiest way to find t0 and ensure spatial overlap of two non-degenerate, non-collinear beams inside UHV environment?

Hi, We do time resolved ARPES, which involves a mid-IR pump (6-20 um) and a UV probe (195 nm). I would like to confidently and quickly find t=0 and spatial overlap of these beams inside of a UHV...

08 June 2020 3,169 2 View