Optical Multi-spectral Strip Filter by Lithography and Ion Beam Assisted Deposition for Multi-spectral Remote Sensing Instrument

In 2015, NSPO (National Space Organization) began to develop the sub-meter resolution optical remote sensing instrument of the next generation optical remote sensing satellite which follow-on to FORMOSAT-5. The multi-spectral strip filter has been developed by NSPO in collaboration with MORRISON Opto-Electronics (MOE) Ltd, meeting the emerging demands of the new TDI CMOS image sensor of the Korsch type optical remote sensing instrument for next satellite mission. This paper represents the technology to deposit the multi-spectral band-pass strip filters on single synthetic silica substrate. The optical multi strip filter is installed in front of TDI CMOS image sensor to capture multi-spectral images of the earth surface. The optical multi strip filter composed of five band-pass filters on single substrate, including three bands in visible bands (400nm to 700nm) called VIS, one panchromatic band including whole visible spectrum and one band in near infrared (NIR). MORRISON Opto-Electronics (MOE) Ltd is responsible to integrate micro-structuring process base on lithography and ion beam-assisted deposition (IAD). These made multi spectral optical thin film coating in a small area with high dimension accuracy deposited possible on the substrate and achieve the robust process of patterning photoresist and removing the photoresist. By repeating the process five times, we have deposited five kinds of band-pass strip filters on single substrate.