Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

InAlGaAs bulk micromachined tunable Fabry-Perot filter for dense WDM systems

: Pfeiffer, J.; Peerlings, J.; Riemenschneider, R.; Genovese, R.; Aziz, M.; Goutain, E.; Kunzel, H.; Gortz, W.; Böhm, G.; Amann, M.C.; Meissner, P.; Hartnagel, H.L.


Materials Science in Semiconductor Processing 3 (2000), No.5, pp.409-412
ISSN: 1369-8001
Journal Article
Fraunhofer HHI ()

In this work we report on micromechanically tunable Fabry-Perot filter concepts for wavelength division multiplexing (WDM) systems. The optical resonator is designed for a cavity length around 30mum in order to increase the filter selectivity while relaxing the demands on the required mirror reflectance. The introduction of micromechanical actuators, utilizing electrothermal and electrostatic principles, allows wavelength tuning of the filter over a range of more than 40nm in the 1.55mum wavelength regime. The movable Bragg mirror, designed as suspended membrane and fabricated with an InP bulk-micromachining technology, consists of a molecular beam epitaxy-grown InAlGaAs quarter-wavelength multilayer stack. The influence of micromechanical actuation and the effect of intrinsic mechanical stress on the mirror deformation has been investigated systematically to optimize the optical filter performance. Filter losses induced by the light absorption within the epitaxial Bragg mirror have been minimized using a highly doped InGaAs/InAlAs composition. Furthermore, low-loss Fabry-Perot filters have been fabricated using InAlGaAs/InAlAs Bragg mirrors. The measured full-width at half-maximum (FWHM) is 0.24nm and a filter insertion loss of 2.8dB has been observed. The FWHM is kept below 0.35nm over an entire tuning range of 40nm for an actuation power of 1.3mW. The bulk-micromachining technology presented here is open for the future development of WDM components, e.g. tunable receivers or laser diodes.