Optical feedback cavity enhanced absorption spectroscopy: effective adjustment of the feedback-phase

Autor: Jan Meinen, Harald Saathoff, Jens Nadolny, J. C. Habig, T. Leisner
Rok vydání: 2011
Předmět:
Zdroj: Applied Physics B. 106:491-499
ISSN: 1432-0649
0946-2171
Popis: Optical-feedback cavity enhanced absorption spectroscopy (OF-CEAS) is a very sensitive technique for the detection of trace amounts of gaseous absorbers. The most crucial parameter in an OF-CEAS setup is the optical phase of the light fed back into the laser source, which is usually controlled by the position of a piezo driven mirror. Various approaches for the analysis of the cavity transmitted light with respect to feedback-phase are presented, and tested on simulated phase and frequency dependent cavity transmission. Finally, we present the performance of a digital signal processor based regulator—employing one of these approaches—in a real OF-CEAS experiment. The results of the simulation show that several algorithms are well suited for the task of control signal generation. They confirm also that with the presented approach, a mode by mode correction of the feedback-phase is possible. Consequently, a regulatory bandwidth of 37 Hz was achieved. This maximum control frequency was limited by the piezo system.
Databáze: OpenAIRE
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