Thermal-optical switching of a silicon based interference filter

We report thermal-optical switching using a silicon based interference filter fabricated by plasma enhanced chemical vapor deposition. A five film structure using high index films of amorphous Si and low index films of SiO2 comprised the device which yielded detector limited 40 ns rise time switching. Operation is in the near infrared spectral region with probe wavelengths of 810 nm and 1.152 micrometers. A 56% contrast ratio is reported when pumped by a 10.6 micrometers CO2 pulsed laser. Lower contrast switching-was also demonstrated with a Nd:YAG pumped dye laser tunable from 600-700 nm. In addition, we have demonstrated that atomic layer thickness precision is not necessary, and suggest several improvements which can further enhance device performance.