Abstract
In modern high precision optical instruments, such as in gravitational wave detectors or frequency references, thermally induced fluctuations in the reflective coatings can be a limiting noise source. This noise, known as coating thermal noise, can be reduced by choosing materials with low mechanical loss. Examination of new materials becomes a necessity in order to further minimize the coating thermal noise and thus improve sensitivity of next generation instruments. We present a novel approach to directly measure coating thermal noise using a high finesse folded cavity in which multiple Hermite-Gaussian modes co-resonate. This method is used to probe surface fluctuations on the order 10-17m/√Hz in the frequency range 30-400 Hz. We applied this technique to measure thermal noise and loss angle of the coating used in Advanced LIGO.
Original language | English |
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Article number | 022001 |
Number of pages | 11 |
Journal | Physical Review D |
Volume | 95 |
Issue number | 2 |
DOIs | |
Publication status | Published - 10 Jan 2017 |
Keywords
- physics.ins-det
- astro-ph.IM
- physics.optics