Infrared bandpass filters deposited using microwave plasma assisted pulsed DC magnetron sputtering are described. Thermo-optical and spectral properties across a range of environmental conditions suitable for use in NDIR gas sensors are demonstrated.

A patterned dual colour filter has been deposited by microwave plasma assisted pulsed DC sputtering (MPAS) and photolithography. Compatibility between MPAS and photolithography for fabrication of patterned optical filters has been demonstrated.

Optical & mechanical properties of closed-field magnetron pulsed DC sputter deposited Al, Au & Ag with Al2O3 protective layer are presented. Results show optical & durability performance suitable for use within NDIR optical gas sensors.