Interferometry in a passive Fabry-Perot cavity with the detection of a standing wave

0434228 - ÚPT 2015 RIV US eng C - Conference Paper (international conference)
Lazar, Josef - Holá, Miroslava - Číp, Ondřej - Hrabina, Jan - Fejfar, Antonín - Stuchlík, Jiří - Kočka, Jan
Interferometry in a passive Fabry-Perot cavity with the detection of a standing wave.
General Assembly and Scientific Symposium (URSI GASS), 2014 XXXIth URSI (Proceedings IEEE). Piscataway: IEEE, 2014. ISBN 978-1-4673-5225-3.
[URSI General Assembly and Scientific Symposium (URSI GASS) 2014 /31./. Beijing (CN), 16.08.2014-23.08.2014]
R&D Projects: GA TA ČR TA02010711; GA TA ČR TE01020233
Institutional support: RVO:68081731 ; RVO:68378271
Keywords : interferometry * Fabry–Perot cavity * standing wave * transparent photodetector
OECD category: Optics (including laser optics and quantum optics)

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.
Permanent Link: http://hdl.handle.net/11104/0238336