Broadband measurement of coating thermal noise in rigid Fabry–Pérot cavities
Broadband measurement of coating thermal noise in rigid Fabry–Pérot cavities
Abstract We report on the relative length fluctuation of two fixed-spacer Fabry–Pérot cavities with mirrors fabricated from silica/tantala dielectric coatings on fused silica substrates. By locking a laser to each cavity and reading out the beat note <?CDATA $\hat{\nu}={{\nu}_{1}}-{{\nu}_{2}}$ ?> <?MML <mml:math><mml:mrow><mml:mover accent='true'><mml:mi>ν</mml:mi><mml:mo>^</mml:mo></mml:mover><mml:mo>=</mml:mo><mml:msub><mml:mi>ν</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:mo>−</mml:mo><mml:msub><mml:mi>ν</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> ?> of the transmitted beams, we find …