Proceedings Article | 21 November 2001
Proc. SPIE. 4592, Device and Process Technologies for MEMS and Microelectronics II
KEYWORDS: Semiconductors, Reflectors, Photodetectors, Optical filters, Reflectivity, Wavelength division multiplexing, Telecommunications, Microopto electromechanical systems, Vertical cavity surface emitting lasers, Tunable filters
The general objective of this presentation is to demonstrate the potential of Micro-Opto-Electro-Mechanical (MEOMS) devices based on III-V semiconductor materials, with a special emphasis on applications for Telecommunications. Unlike more classical MOEMS devices, such as shutters, rotating mirrors, etc..., which utilize the concept of geometrical optics, III-V semiconductor MOEMS structures presented here operate via the manipulation of optical interferences. The basic building block consists in a multi-air-gap/suspended membrane structure which can be micromachined using multi-layered III-V semiconductor based heterostructures. This building block is very generic in that it can be designed in a variety of manners allowing for the production of a wide range of optical functions. As a matter of fact the wavelength dependence of the transmittance or of the reflectance depends strongly on the number, the thickness and the successive air- gap/semiconductor pairs, and, given the high index contrast between air and semiconductor, a wide choice of spectral responses can be obtained with very few of them. In addition, a wide choice of electro-opto-mechanical modulations of the spectral responses can be produced by moving vertically, via electrostatic actuation, one or several suspended membranes independently. One single device can be designed in order to achieve one or several functions. Such devices as tunable filters for WDM systems, tunable photodetectors, tunable VCSEL, which are based on this generic building block, will be presented.
