Advanced LIGO subsystems
are the organizational units of the overall project. Follow the links below to view the mission and progress of each subsystem.
Auxiliary Optics | Core Optics |
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Data Acquisition | Data and Computing Systems |
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Facilities Modifications |
Input Optics |
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Interferometer Control |
Pre-Stabilized Laser |
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Seismic Isolation |
Suspensions |
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Advanced LIGO News
Development of Input and Recycling Mirror Suspensions Continues
October 2011
Say "suspensions" at LIGO and chances are good that your listener will presume you are making reference to a quadruple suspension. A quad is a four-stage multiple pendulum with a 40 kg Advanced LIGO mirror occupying the lowest stage, hanging from the stage above by four thin glass fibers. LIGO's quad suspensions will hold the four most sensitive mirrors in each interferometer, the mirrors that reflect laser light up and down the 4-kilometer arms. Each detector will contain a number of additional suspended mirrors. Some of these optics will occupy single-stage suspensions in which the mirror rests on a wire loop that fastens directly to the top of the suspension cage. Others are two-stage pendulums (doubles) and others contain three stages (triples). Beam splitters, for instance, will rest at the bottom stage of triple suspensions.
A team at LIGO Livingston (LLO) has worked for several months on the assembly of large and small triple suspensions for optics that will reside between the main laser and the beam splitter and between the beam splitter and a detector's output port. Mirrors slated for these types of suspensions include power recyclers, signal recyclers and mode cleaner optics. The assemblies in these photographs are "dirty." Although prepped and tested in clean room conditions at LLO, the suspensions were constructed of parts that didn't follow the rigorous path of cleaning and baking that's necessary for LIGO's vacuum-rated components. These assemblies will serve as prototypes for testing, evaluation and characterization. Information gathered from these dirty builds will shape the assembly processes that will unfold later at LLO and LHO (LIGO Hanford), yielding production suspensions that will make their way to optical tables inside the vacuum envelopes of the L1, H1 and H2 interferometers.
Image 1: Two of the assemblers pose with the small triple
Image 2: A complete small triple with metal masses rather than glass
Image 3: Installing a stage three mass on a large triple
Image 4: Aligning a stage three mass on a large triple
aLIGO News Archive
August 2016 -- LIGO Reports O1 Results
June 2016 -- Another Black Hole Merger
Feburary 2016 -- First Gravitational Wave Detection
November 2015 -- O1 Progress Report
August 2015 -- Final Preparations for the O1 Run
February 2015 -- Hanford's H1 Achieves Two-Hour Lock
July 2014 -- Livingston Commissioning Progress
June 2014 -- Livingston Locks the L1 Interferometer
December 2013 -- Livingston Installs End Station Payloads
September 2013 -- Half-interferometer Test Closes
June 2013 -- DRMI Test at Livingston
May 2013 -- Arm Length Stabilization
November 2012 -- One-arm Test at Hanford
September 2012 -- LIGO Begins Locking Optical Cavities
August 2012 -- Installation of Stray Light Controls
July 2012 -- Small Optic Suspenions Enter L1
April 2012 -- First Cartridges Enter the Vacuum
November 2011 -- Glass Fiber Suspensions in Production
October 2011 -- Continued Suspension Development
July 2011 -- Hanford's H2 Becomes a 4K
May 2011 -- LLO Laser Installation Completed
March 2011 -- Input and Output Tubes Undergo Removal
February 2011 -- New Laser Enclosure Takes Shape
December 2010 -- Initial LIGO Comes Out of the Vacuum
October 2010 -- S6 Yields to Advanced LIGO
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