Optical Monitoring of VLA Coating Process Using HyperSpectral Imaging

"Surface Optics Corporation (SOC) proposes the use of an in-house developed real-time hyper-spectral imaging system, known as the SOC-700, for monitoring and controlling optical coating processes. Multi-layer coatings have been developed to provide verylow absorption (VLA) for high power laser beams. Despite the progress made in the field of multilayer optical coatings, damage by the high power laser beams remains a problem because of the inability to precisely monitor and control the vacuum coatingprocesses.The SOC-700 is comprised of a high-speed, low-noise visible/near-IR camera, high quality spectrometer and integrated scanning system and software. This system can obtain and process 100 megabyte hyperspectral data cubes in 6.4 seconds. The data cubecontains spectral information on 120 different color bands per pixel over a wavelength range of 0.4 to 0.9 microns. By using this camera to record color changes of a growing optical film, information pertaining to the thickness of the growing film, andthe film's refractive index, may be directly computed in real-time.Surface Optics Corporation also specializes in optical coating processes and will test this hyperspectral camera by integrating it with one of SOC's vacuum deposition chambers as part of this SBIR. Development of this real-time hyperspectral process monitoring technology for vacuum applied coatings, has a very great potential for use in the optical coating market. Thi