Design and Fabrication of an Integrated Dual-Channel Thin-Film Filter for the Mid-Infrared

Micro-filters fabricated using integration methods is now the trend for multichannel filters in imaging spectrum systems. Traditional bandpass are mainly separately by multilayered thin films and then glued together. This approach involves complexity of precision cutting, dicing, adhesive bonding; therefore, possibility miniaturization quite limited. In this work, a dual channel film filter mid-infrared was lift-off process. The structure 4-cavity Fabray–Perot (F-P) type designed optimized. over range 3.55–3.75 µm with full width at half maximum (FWHM) 274 nm 4.85–4.95 FWHM 246 were obtained 4.5 joint width. average transmittance more than 83.5% optical density value cutoff 3. thickness measured error analyzed. results show that error, especially spacer layers, induces degradations peak transmission bandwidth. kind has important application space remote sensing, military, civil fields.