Polarization- and aliasing-resistance Michelson heterodyne laser vibration measurer based on double acousto-optic modulation and non-polarizing light splitting

• Main Authors: HE ZHANGQIANG, JIU YUANWEI, JIANG HONGLEI, TAN JIUBIN, CUI JUNNING
• Format: Patent
• Language: English
• Published: 21.10.2015
• Subjects: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; PHYSICS; TESTING

A polarization- and aliasing-resistance Michelson heterodyne laser vibration measurer based on double acousto-optic modulation and non-polarizing light splitting belongs to the field of laser interference measurement. A non-polarizing beam splitter (NBS) is adopted to perform light splitting and then form a reference arm and a measuring arm, incident light beams on the reference arm and the measuring arm generate diffraction via acousto-optic modulators, and frequency-shifted first-stage diffraction light are adjusted through light beam folding elements, so light beam propagation directions are parallel to the incident light beams; reflected light is located over acousto-optic modulators through adjustments of cube-corner prisms, so measuring light and reference light respectively pass through the acousto-optic modulators for one time; and the reference cube-corner prism and the measuring cube-corner prism are adjusted, so light beam superposition occurs when the reference light and the measuring light pass through the non-polarizing beam splitter (NBS) again, and an interference is generated. Heterodyne laser measuring is achieved through adoption of less optical elements, optical path adjustments are simple, problems of polarization leakage, polarization aliasing, complex optical path adjustments and the like which exist in an existing technical scheme can be effectively solved, and the laser vibration measurer has an obvious technical advantage in the ultra-precision vibration measurement field.