Displacement measurement with intracavity interferometry

0434164 - ÚPT 2015 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Lazar, Josef - Holá, Miroslava - Fejfar, Antonín - Stuchlík, Jiří - Kočka, Jan - Oulehla, Jindřich - Číp, Ondřej
Displacement measurement with intracavity interferometry.
Optical Micro- and Nanometrology V. (Proceedings of SPIE 9132). Bellingham: SPIE, 2014, 913210:1-6. ISSN 0277-786X.
[Optical Micro- and Nanometrology /5./. Brussels (BE), 15.04.2014-17.04.2014]
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; GA TA ČR TA01010995; GA MŠMT(CZ) LO1212
Institucionální podpora: RVO:68081731 ; RVO:68378271
Klíčová slova: antireflective coatings * Fabry–Perot interferometers * interferometry * lasers * photodetectors * refractive index * silicon
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 standingwave 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/11104/0238300