Advanced LIGO Input Optics

The input optics (IO) conditions light from the pre-stabilized laser (PSL) for injection into the main interferometer.
The design requirements for the Advanced LIGO Input Optics Subsystem include the requirements for the RF modulation of the light, acquisition and operation of the mode cleaner, mode matching of the light to the interferometer, and beam steering into the interferometer. The scope of the IO includes the following tasks and hardware:

• phase modulation Pockels cells
• intermediate frequency and intensity stabilization
• power control into interferometer
• photodetectors and related protective shutter (if needed)
• cabling
• active jitter suppression system
• mode cleaner optics
• Faraday isolators - optical isolation of the PSL
• mode matching telescopes
• distribution of light for length and alignment sensing and control