Satcom Optical Filters And Coatings
Iridian offers over 20 years of experience in producing industry leading optical telecommunication and datacom filters for terrestrial systems. Commercial satcom networks will consist of constellations of 100’s to 1000’s of satellites in an interconnected low earth orbit (LEO) mesh. Many of these systems rely on an optical intersatellite link (OISL) architecture to connect satellites via laser based optical communications. Optical filters provide wavelength selectivity to these systems addressing different functional needs from solar rejection windows to beam steering wavelength selective dichroic filters.
Solar Rejection Window (SRW)
Iridian’s solar rejection windows (SRWs) are designed to allow the transmission of the communication band between satellites while blocking the background solar radiation. This provides an improved signal-to-noise ratio while minimizing solar heating inside the satellite.
Typical optical filter performance requirements include a high transmittance in signal band (typically 1550 nm), a broad deep blocking of the solar spectrum, up to 150 mm window sizes, and a low transmitted wavefront error (TWE).
Dichroic Filters
Iridian’s dichroic filters are meant to enable a receiver to selectively receive specific wavelength bands of interest. These filters can be used as stand-alone clean up filters or in a series to direct different signals to different detectors in the optical train. These optical filters require high transmittance, high reflection, steep edges, and possibly the preservation of polarization (for QKD encryption signals).
For additional information and examples of available satcom optical filters and coatings, download the available brochure.