Publication detail

Displacement measurement with intracavity interferometry

LAZAR, J. HOLÁ, M. FEJFAR, A. STUCHLÍK, J. KOČKA, J. OULEHLA, J. ČÍP, O.

Original Title

Displacement measurement with intracavity interferometry

Type

conference paper

Language

English

Original Abstract

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 theFabry-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 wasachieved thanks to a design as an optimized set of interference layers acting as an antireflection coating. The principle is demonstrated on an experimental setup.

Keywords

antireflective coatings; Fabry Perot interferometers; interferometry; lasers; photodetectors; refractive index; silicon

Authors

LAZAR, J.; HOLÁ, M.; FEJFAR, A.; STUCHLÍK, J.; KOČKA, J.; OULEHLA, J.; ČÍP, O.

Released

1. 5. 2014

ISBN

0277-786X

Periodical

Proceedings of SPIE

State

United States of America

Pages from

913210:1

Pages to

6

Pages count

6