Phase difference measurer and heterodyne interference measuring system using it

Application Number: 00107057
Application Date: 2000.04.24
Publication Number: 1320812
Publication Date: 2001.11.07
Priority Information:
International: G01J9/02
Applicant(s) Name: Zhou Zheng
Inventor(s) Name: Zhou Zheng
Patent Agency Code: 31100
Patent Agent: li ling
Abstract A phase-difference measurer and its heterodyne interference measuring system are disclosed. A differential amplifier is used to find out the difference value between two phase modulated measured signals with same amplitude and phase modulated reference signal or the light signal from heterodyne interferometer and then amplifying it in order to reduce background noise and convert the phase modulated signals to amplitude modulated signals. A amplitude demodulator is used to take instantaneous amplitude value which is used to determine the phase change and further the phase difference value. Its advantages are high speed and high sensitivity.