THERMAL-OPTICAL SWITCHING OF A SILICON-BASED INTERFERENCE FILTER

Thermal-optical switching using a silicon based interference filter fa bricated by plasma enhanced chemical vapor deposition is reported. A f ive film structure using high index films of amorphous Si and low inde x films of SiO2 comprised the device which yielded detector limited 40 ns rise time switching. Operation is in the near infrared spectral re gion with probe wavelengths of 810 nm and 1.152 mum. A 56% contrast ra tio is reported when pumped by a 10.6 mum CO2 Pulsed laser. Lower cont rast switching was also demonstrated with a Nd:YAG pumped dye laser tu nable from 600 to 700 nm. In addition, it is demonstrated that atomic layer thickness precision is not necessary, and several improvements t hat can further enhance device performance are suggested.