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

0422033 - ÚPT 2014 FR eng C - Conference Paper (international conference)
Holá, Miroslava - Hrabina, Jan - Číp, Ondřej - Oulehla, Jindřich - Lazar, Josef
Position sensing with standing wave detection within a pasive Fabry-Perot cavity.
NanoScale 2013. 10th Seminar on Quantitative Microscopy (QM) and 6th Seminar on Nanoscale Calibration Standards and methods.. Paris: Nanometrology Group, 2013, s. 111.
[NanoScale 2013. Seminar on Quantitative Microscopy (QM) /10./ and Seminar on Nanoscale Calibration Standards and Methods /6./. Paris (FR), 25.04.2013-26.04.2013]
Institutional support: RVO:68081731
Keywords : nanometrology * nanopositioning * interferometry * refractive index * nanoscale
Subject RIV: BH - Optics, Masers, Lasers

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/11104/0228282