Title: Heterodyne frequency-shifting-type twin laser interferometer with common-mode suppressed frequency shift interference
Application Number: 93109465 Application Date: 1993.07.29
Publication Number: 1085315 Publication Date: 1994.04.13
Approval Pub. Date: Granted Pub. Date: 1997.04.30
International Classifi-cation: G01B9/02
Applicant(s) Name: Chen Fu Address: 330027
Inventor(s) Name:
Attorney & Agent:
Abstract:
     Twin laser interferometer used as precise length meter or speedometer features that a reference light way is added to Michelson interferometer to constitute another interferometer by sharing same laser and reflector. Reciprocating reflector becomes a heterodyne frequency-shift plane to reduce low-frequency noise error. The influence of photoelectric frequency variation caused by laser frequency shift to two interferometers are same (common mode), while freq. synthesizing frequency shift error is cancelled. Its relative measuring error is<1X10 the power -18.
Time: 8