Multichannel bandpass filters utilizing multilayer photonic crystal.

We demonstrate multichannel optical bandpass filters utilizing alternating dielectric multilayers stacked on a patterned substrate. A microstructured Si/SiO(2) multilayer was formed by rf biased magnetron sputtering process on a fused silica substrate with surface gratings. The bandwidths of each filter channel were measured to be 50~175 nm in the near infrared region. Control of center wavelength and bandwidth by the grating pitch was verified.