All-reflective coupling of two optical cavities with 3-port diffraction gratings

Oliver Burmeister, Michael Britzger, André Thüring, Daniel Friedrich, Frank Brückner, Karsten Danzmann, Roman Schnabel
2010 Optics Express  
The shot-noise limited sensitivity of Michelson-type laser interferometers with Fabry-Perot arm cavities can be increased by the so-called power-recycling technique. In such a scheme the power-recycling cavity is optically coupled with the interferometer's arm cavities. A problem arises because the central coupling mirror transmits a rather high laser power and may show thermal lensing, thermo-refractive noise and photo-thermo-refractive noise. Cryogenic cooling of this mirror is also
more » ... g, and thus thermal noise becomes a general problem. Here, we theoretically investigate an all-reflective coupling scheme of two optical cavities based on a 3-port diffraction grating. We show that power-recycling of a high-finesse arm cavity is possible without transmitting any laser power through a substrate material. The power splitting ratio of the three output ports of the grating is, surprisingly, noncritical.
doi:10.1364/oe.18.009119 pmid:20588760 fatcat:2vxchaz2o5fajifmyqxx2oewhq