Berlin 2012 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 13: Poster II

DF 13.22: Poster

Mittwoch, 28. März 2012, 15:00–17:30, Poster E

Hydrophones based on photonic crystals — Timm Schaer^1,2, •Juliane Tschentscher², and Mirco Imlau² — ¹ATLAS ELEKTRONIK GmbH, Sebaldsbrücker Heerstr. 235, D-28309 Bremen — ²Department of Physics, University of Osnabrück

Hydroacoustic sensors commonly consist of piezoelectric ceramics that convert acoustical pressure to electric signals. However, their application in the deep sea (>1800 m depth) with remotely-operated undersea vehicles (ROV) is limited because of large signal losses in copper based connecting wires. In this context, fiber-based photonic networks that include optical hydrophones represent a promising solution. Here, we focus on the application of photonic crystals as highly sensitive sensor elements in hydroacoustic devices. Photonic crystals are artificial structured materials on the scale of light wavelength. Because of their unique sensitivity to alterations in the periodic structure, they are particularly suited for the detection of mechanical pressure and, hence, for the detection of acoustic waves. We have selected polymethymethacrylat (PMMA) as base material because of its Young’s modulus, transparency and chemical stability. We present our results on the recording of quasi-periodic structures by means of exposure to ns- and fs-laser pulses. The structures that allow the control of light at the telecommunication wavelength (1.55 µm) are analyzed by photo spectroscopy and light diffraction. The response of the device to dynamic changes of mechanical pressure under seawater conditions is discussed.

Financial support by the DFG (IM37/5, INST 190/137-1) is gratefully acknowledged.