Integrated Tunable Filter for Wavelength Division Multiplexing

Recent demonstrations in the field of microelectromechanical structures (MEMS) have shown it to have great potential for applications in photonics. The high speed, low-power, sub-micron motion which is typical of these structures makes them excellent candidates, particularly for tunable filters. This is in contrast to acousto/electro-optic devices which tend to be power hungry, or piezo based devices which require labor intensive manufacturing. Etalon has developed a process for fabricating MEMS based tunable filters with the potential for an exceptional performance/cost ratios. These devices take the form of micro-fabricated Fabry-Perot filters. Fabrication is made possible by an innovative process which allows for the direct incorporation for high quality dielectric mirrors into structures which are surface micromachined. The result is a device which is well suited for WDM applications. Throughputs in excess of 90%, finesse > 300, response times of several microseconds, and tuning ranges over a micron can be achieved with these devices. In addition, the benign nature of the fabrication process facilitates integration with driver electronics, making possible fully integrated optoelectronic filters. Etalon will fabricate filters on glass substrates to be characterized. Issues concerning fiber coupling and driver electronics will also be addressed.