Position sensing with standing wave detection within a passive Fabry-Perot cavity

0426196 - ÚPT 2015 ME eng A - Abstrakt
Holá, Miroslava - Hrabina, Jan - Číp, Ondřej - Oulehla, Jindřich - Lazar, Josef
Position sensing with standing wave detection within a passive Fabry-Perot cavity.
21th annual International Conference on Advanced Laser Technologies ALT´13. Book of Abstracts. Budva: University of Montenegro, 2013. s. 148.
[ALT´13. Annual International Conference on Advanced Laser Technologies /21./. 16.09.2013-20.09.2013, Budva]
Grant CEP: GA ČR GPP102/11/P820; GA MŠMT ED0017/01/01; GA MŠMT EE2.4.31.0016; GA TA ČR TA02010711; GA TA ČR TE01020233
Institucionální podpora: RVO:68081731
Klíčová slova: position sensing * standing wave detection * Fabry-Perot cavity
Kód oboru RIV: BH - Optika, masery a lasery

We present a measuring technique for displacement and position sensing over a limited range with detection of standing-wave pattern inside of a passive Fabry-Perot cavity. The concept considers locking of the laser optical frequency and the length of the Fabry-Perot cavity in resonance. Fixing the length of the cavity to e.g. a highly stable mechanical reference allows to stabilize wavelength of the laser in air and thus to eliminate especially the faster fluctuations of refractive index of air due to air flow and inhomogeneities. Sensing of the interference maxima and minima within the cavity along the beam axis has been tested and proven with a low loss photoresistive photodetector based on a thin polycrystalline silicon layer. Reduction of losses was achieved thanks to a design as an optimized set of interference layers acting as an antireflection coating. The principle is demonstrated on an experimental setup.
Trvalý link: http://hdl.handle.net/11104/0235681