Abstract
An automatic Michelson-type fringe counting interferometer (Lambda-meter) allowing for interpolation to 1/50 of a wavelength is described. The movable part of the interferometer consists of a carriage which slides on two polished steel bars and transports two corner cube retroreflectors. A missing-fringe digital control logic identifies and instantaneously corrects for laser interference fringe dropouts, caused by short-time laser light instabilities. By exact superposition of the beams of a He 22Ne laser stabilized to a line of I 2 and the laser to be measured in the interferometer, absolute wavelength measurements with a precision of 1 to 2 parts in 10 8 were performed. Real-time control of the measurement, data acquisition and calculation of the wavelength are provided by a microcomputer.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
