O1.4 - Adaptive interferometer with optoelectronic feedback
- Event
- SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg - Band
- Proceedings OPTO 2009 & IRS² 2009
- Chapter
- OPTO 1 - Interferometry
- Author(s)
- I. Sokolov, M. Bryushinin - Russian Academy of Sciences, St.-Petersburg, Russia
- Pages
- 41 - 46
- DOI
- 10.5162/opto09/o1.4
- ISBN
- 978-3-9810993-6-2
- Price
- free
Abstract
Detection of low-amplitude acoustic vibrations of real objects, such as ultrasonic transducers, composite materials, biological objects, metal production, MEMS is an important scientific and technical problem. Homodyne laser vibrometers are suitable for practical applications in this regard for their high sensitivity which is limited in principle only by shot-noise of the laser used. These vibrometers allow detection at a distance, with high spatial localization of the measurement region and wide frequency range. However, their utilization is restrained by several problems such as slow phase drifts in the interferometer arms due to environmental reasons, necessity of fine optical adjustment and suppression of laser amplitude noise. Wide-gap photorefractive materials offer an elegant way to solve the problem of keeping operation interferometer point constant. The crystal replaces the conventional beamsplitter and can be controlled not only electrically but also optically, i.e., based on the principles of nonlinear optics. In addition, it can be multilayered. Such a multilayered adaptive beamsplitter is nothing else but a volume dynamic hologram recorded by the reference and signal waves. Adaptive detectors based on the effect of the non-steady-state photo-electromotive force (photo-EMF) are promising for sensor applications.