| Micromachined wavelength selective microbolometers are fabricated, characterized and modeled using a transmission line equivalent circuit. The amount of power absorbed by the device is adjusted using interference effects, resulting in a device with wavelength depend response characteristics. Using micromachining, significant improvement in thermal performance is achieved by removing the substrate from the bolometer, supporting it with long and narrow suspension legs to increase the thermal impedance. Constructive interference produced by a mirror placed a quarter wavelength of the incoming infrared signal behind the microbolometers is used to enhance the absorption of the microbolometer. The model of power coupling is verified by optical measurement at several infrared wavelengths. |
