The Z-Beamlet Laser (ZBL), like others in its class of high peak power lasers, requires optics of large dimensions (up to a meter or even more) over which the high peak laser intensities can be distributed at levels below thresholds for laser damage to the optics. Equally as critical to the avoidance of laser damage are high damage threshold optical thin film coatings for the large optics. The ZBL primary mission of providing backlighting diagnostics for Sandia’s Z-Accelerator on an almost daily basis combines with current upgrades to Petawatt laser systems to accentuate even more Sandia’s need for large optics with specialized thin film coatings. Such large optics coatings with high laser damage thresholds are not typically available from commercial sources. To meet this need, Sandia has constructed the Optics Support Facility (OSF) and has established a state-of-the-art large optics coating operation.
The OSF adjoins the ZBL high bay facility and provides Class 100 clean room space devoted to the large-optics coating operation and to optical metrology for characterizing the wave front and spectral properties of large optics and their coatings. The OSF and coating operation enable Sandia to meet its demand for large optics coatings and also to develop and test coating designs to meet the most stringent requirements for resistance to laser damage. These unique capabilities put Sandia in a position to not only advance the state-of-the-art but also to contribute to cooperative efforts within the high-energy laser community in this strategic area of high-energy laser large optics coatings.
Layout of OSF building and location relative to the laser high bay
The design phase of the OSF and the 90” large optics coater started in 2002. The 90” coater was manufactured by Vacuum Process Technology (VPT) in 2002 – 2003 and underwent coating process control development at VPT in 2003 to 2004. From 2004 to 2005 process control development continued and the 90” coater also started to be used for production coating runs. Meanwhile, the OSF construction took place during 2003 – 2004 and the OSF began being used for building and testing optical modules and layouts in 2004 – 2005. The 90” large optics coater was moved from VPT to Sandia in June 2005. Integration of the 90” coater into the OSF was complete by the fall of 2005 and coating production runs at Sandia started in November 2005.
Inside view of 90” coater
Outside view of 90” coater