2015/02/08 by Chris L. Mueller, P. Fulda, Mueller, Chris L. +22
Engineering · Physics and Astronomy · #Adaptive optics and wavefront sensing #Advanced Frequency and Time Standards #Advanced Measurement and Metrology Techniques #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Optics (physics.optics) #Photonic and Optical Devices
paper · pdf · doi:10.48550/arxiv.1502.02284
openalex publication_date 2015/02/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Thermal lensing in resonant optical interferometers such as those used for\ngravitational wave detection is a concern due to the negative impact on control\nsignals and instrument sensitivity. In this paper we describe a method for\nmonitoring the thermal state of such interferometers by probing the\nhigher-order spatial mode resonances of the cavities within them. We\ndemonstrate the use of this technique to measure changes in the Advanced LIGO\ninput mode cleaner cavity geometry as a function of input power, and\nsubsequently infer the optical absorption at the mirror surfaces at the level\nof 1 ppm per mirror. We also demonstrate the generation of a useful error\nsignal for thermal state of the Advanced LIGO power recycling cavity by\ncontinuously tracking the first order spatial mode resonance frequency. Such an\nerror signal could be used as an input to thermal compensation systems to\nmaintain the interferometer cavity geometries in the presence of transients in\ncirculating light power levels, thereby maintaining optimal sensitivity and\nmaximizing the duty-cycle of the detectors.\n