The advanced LIGO input optics.

The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design.

[1]  J. E. Harvey,et al.  Modeling of light scattering in different regimes of surface roughness. , 2011, Optics express.

[2]  C. Bonnin,et al.  Study of RTP Crystal Used as Electro-Optic Modulator , 2006 .

[3]  G. M. Harry,et al.  Advanced LIGO: the next generation of gravitational wave detectors , 2010 .

[4]  R L Byer,et al.  Spatial and temporal filtering of a 10-W Nd:YAG laser with a Fabry--Perot ring-cavity premode cleaner. , 1998, Optics letters.

[5]  David H. Reitze,et al.  Suppression of self-induced depolarization of high-power laser radiation in glass-based Faraday isolators , 2000 .

[6]  G. Mueller.  Beam jitter coupling in advanced LIGO. , 2005, Optics express.

[7]  B. J. Meers,et al.  Automatic alignment of optical interferometers. , 1994, Applied optics.

[8]  John L. Hall,et al.  Laser phase and frequency stabilization using an optical resonator , 1983 .

[9]  D. Z. Anderson,et al.  Alignment of resonant optical cavities. , 1984, Applied optics.

[10]  Large-angle scattered light measurements for quantum-noise filter cavity design studies. , 2012, Journal of the Optical Society of America. A, Optics, image science, and vision.

[11]  Gary C. Bjorklund,et al.  Residual amplitude modulation in laser electro-optic phase modulation , 1985 .

[12]  Results of the Virgo central interferometer commissioning , 2004 .

[13]  A.K. Poteomkin,et al.  Compensation of thermally induced modal distortions in Faraday isolators , 2004, IEEE Journal of Quantum Electronics.

[14]  M. M. Casey,et al.  Automatic beam alignment for the mode-cleaner cavities of GEO 600. , 2004, Applied optics.

[15]  A. Araya,et al.  Optical mode cleaner with suspended mirrors. , 1997, Applied optics.

[16]  K. Kokeyama,et al.  Residual amplitude modulation in interferometric gravitational wave detectors. , 2013, Journal of the Optical Society of America. A, Optics, image science, and vision.

[17]  E. Khazanov,et al.  High-vacuum-compatible high-power Faraday isolators for gravitational-wave interferometers , 2012 .

[18]  S. Klimenko,et al.  Advanced LIGO , 2014, 1411.4547.

[19]  Daniel A Shaddock,et al.  Arm-length stabilisation for interferometric gravitational-wave detectors using frequency-doubled auxiliary lasers. , 2011, Optics express.

[20]  J. Zavada,et al.  Relationship between surface scattering and microtopographic features (A) , 1979 .

[21]  C Bogan,et al.  Stabilized high-power laser system for the gravitational wave detector advanced LIGO. , 2012, Optics express.

[22]  F. Barone,et al.  Advanced Virgo: a 2nd generation interferometric gravitational wave detector , 2014 .

[23]  Peter Fritschel,et al.  Alignment of an interferometric gravitational wave detector. , 1998, Applied optics.

[24]  Antonio Lucianetti,et al.  Thermal effects in the Input Optics of the Enhanced Laser Interferometer Gravitational-Wave Observatory interferometers. , 2012, The Review of scientific instruments.

[25]  A. Grant,et al.  Test of an 18‐m‐long suspended modecleaner cavity , 1996 .

[26]  A. Lucianetti,et al.  Characterization of thermal effects in the Enhanced LIGO Input Optics , 2011, 1112.1737.

[27]  E. King,et al.  In situ characterization of the thermal state of resonant optical interferometers via tracking of their higher-order mode resonances , 2015, 1502.02284.

[28]  S. Kawakami,et al.  Compact Faraday rotator for an optical isolator using magnets arranged with alternating polarities. , 1986, Optics letters.

[29]  D. Gloge,et al.  Scattering from dielectric mirrors , 1969 .

[30]  C. Broeck,et al.  Advanced Virgo: a second-generation interferometric gravitational wave detector , 2014, 1408.3978.

[31]  N. Lockerbie,et al.  Sensors and actuators for the Advanced LIGO mirror suspensions , 2012, 1205.5643.

[32]  Winkler,et al.  Heating by optical absorption and the performance of interferometric gravitational-wave detectors. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[33]  A. Rüdiger,et al.  Resonant sideband extraction: a new configuration for interferometric gravitational wave detectors , 1993 .

[34]  Compensation of thermally induced depolarization in Faraday isolators for high average power lasers. , 2011, Optics express.

[35]  B. J. Meers,et al.  Recycling in laser-interferometric gravitational-wave detectors. , 1988, Physical review. D, Particles and fields.

[36]  Peter Fritschel,et al.  DC readout experiment in Enhanced LIGO , 2011, 1110.2815.