THE LGSF LASER SYSTEM - Thirty Meter Telescope

TMT.AOS.DRD.09.003.DRF05 Page 12 of 30REQUIREMENTS DOCUMENT FOR THE LGSF LASER SYSTEM August 25, 2009It is assumed that the Laser System is composed of several identical Laser Units and oneLaser Sequencer. Each Laser Unit consists of one Laser Head and one Laser Controller.The number of Laser Units is defined as follows and in requirements [REQ-3-LAS-0310]and [REQ-3-LAS-0330]:- First Light Laser System: six plus one spare (seven total) Laser Units to generatethe NFIRAOS asterism. The First Light Laser System will also generate the MIRAOand GLAO asterisms.- Final Laser System: eight plus one spare (nine total) Laser Units to generate theMOAO asterism.Although only seven Laser Units are required at first light, the Laser System shall bedesigned to be upgradeable to include nine Laser Units.The role of the Laser Sequencer is to coordinate the actions of the multiple LaserControllers and to interface with the AO Sequencer.The Laser Units shall also work as autonomous systems and include for exampleengineering user interfaces for engineering maintenance purposes.