Fabry-Perot tunable filter using a bonded pair of transparent substrates

A tunable Fabry-Perot filter comprising:

• a pair of silica substrates having parallel generally planar facing principal surfaces including spaced-apart facing reflective surface regions that are at least partially reflective at least over a selected wavelength range, the spaced-apart facing reflective surface regions defining an optical gap therebetween, at least one silica substrate of the pair of silica substrates being light-transmissive at least over the selected wavelength range to enable optical coupling with the optical gap through the at least one silica substrate, wherein said facing reflective surface regions each have rigid support provided by supporting portions of the corresponding substrate that move with the facing reflective surface regions;
• and
• electrodes disposed on the parallel generally planar facing principal surfaces of the silica substrates, the electrodes on the parallel generally planar facing principal surfaces defining an electrode gap therebetween such that electrical biasing of the electrodes simultaneously modifies the optical and electrode gaps.

The tunable Fabry-Perot filter comprising:

• a pair of substrates having parallel generally planar facing principal surfaces including spaced-apart facing reflective surface regions that are at least partially reflective at least over a selected wavelength range, the spaced-apart facing reflective surface regions defining an optical gap therebetween, the facing reflective surface regions including distributed Bragg reflectors, at least one substrate of the pair of substrates being light-transmissive at least over the selected wavelength range to enable optical coupling with the optical gap through the at least one substrate, wherein said facing reflective surface regions each have rigid support provided by supporting portions of the corresponding substrate that move with the facing reflective surface regions;
• and
• electrodes disposed on the parallel generally planar facing principal surfaces of the substrates, the electrodes on the parallel generally planar facing principal surfaces defining an electrode gap therebetween such that electrical biasing of the electrodes simultaneously modifies the optical and electrode gaps.