Active feedback regulation of a Michelson interferometer to achieve zero-background absorption measurements.
An active phase-controlling scheme based on a proportional-integral-derivative-controlled piezoelectric transducer is presented with the purpose of stabilizing a quasi-zero-background absorption spectrometer. A fiber-based balanced Michelson interferometer is used, and absorption due to a gas sample in one of its arms results in an increased light signal to a detector, which otherwise, thanks to destructive interference, experiences a very low light level. With the presented approach, the sensitivity of already potent absorption measurement techniques, e.g., based on modulation, could be improved even further.
Atomic Physics Division, Lund University, P.O. Box 118, SE-221 00, Lund, Sweden. patrik.lundin@fysik.lth.se
Patrik
P
Lundin
Zuguang
Z
Guan
Sune
S
Svanberg