Electro-optic crystal Z axis deviation angle measurement device and measurement method

The invention discloses an electro-optic crystal Z axis deviation angle measurement device and a measurement method. The device comprises a laser (101), a microscope objective (102), a pin hole (103), an adjustable diaphragm (104), a collimating lens (105), a polarizer (106), a reflector (107), a beam splitting cube (108), an optical screen (109), a first lens (110), a to-be-measured crystal (111), a second lens (112), an analyzer (113), an imaging lens (114), a detector (115) and a computer processing system (116) which are placed in sequence along an optical path, wherein the polarizer (106) and the analyzer (113) have vertical polarized directions; the first lens (110) and the second lens (112) are strictly conjugate; and the beam splitting cube (108), the reflector (107), the to-be-measured crystal (111) and the optical screen (109) form a Michelson interference system. a Michelson interference principle is used for realizing precise crystal positioning, image matching algorithm is adopted for realizing melatope center calculation, and precise electro-optic crystal Z axis deviation angle measurement can be completed. Compared with other devices and methods, the device and the method of the invention have the advantages of high measurement precision, simple measurement method, small measurement system errors and good measurement repetition.