The invention belongs to the technical field of optical instruments and meters, and provides a phase measuring device for a
laser interference photoetching
system and a using method thereof. The phasemeasuring device comprises a first wave plate, a first polarization splitting
prism, a fourth wave plate, a backward reflecting mirror, a
third wave plate, a reflecting mirror, a second wave plate, apolarizing film, a second polarization splitting
prism, a third polarization splitting
prism, a first photoelectric
detector, a second photoelectric
detector and a base, wherein the first polarization splitting prism, the second polarization splitting prism, the third polarization splitting prism, the first photoelectric
detector and the second photoelectric detector are fixed on the base; the first wave plate, the second wave plate, the
third wave plate and the fourth wave plate are respectively arranged around the first polarization splitting prism; the polarizing film and the emergent surface of the third polarization splitting prism, the backward reflecting mirror outside the fourth wave plate, and the reflecting mirror outside the
third wave plate form a light
path system for phase measurement. An interference measurement
signal is resolved to obtain a measurement light phase, and the device and the method are used for fringe control of variable-period interference
exposure.