= Optical Levers = '''''Related subgroups:''''' VIS, IOO, MIF, VAC, CRY... ---- '''[[KAGRA/Subgroups/AOS| back to AOS top]]''' == Action Items == A/I化できたもの、されたもののリスト || '''AI_AOS_OPLEV#''' || '''Identified on'''|| '''Assigned to '''||'''Status'''|| '''Description''' || || 001 仕様の確認||20120401||Michimura|| Closed（20120427）||[[http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/LCGT/subgroup/AOS/Meetings#m9th|議事録など]]参照。一応これはこれでclosedということにしておく。|| || 002 プロトタイプ設計、製作、テスト||20120401||Agatsuma, Takahashi|| 進行中||光源の選定、寿命の確認。Detectorの選定、線形性の確認etc。ちゃんと列挙した方がいいのだけれども。|| || 003 光学系の概念設計||20121112||Agatsuma, Takahashi||進行中 || 光てこの設置位置を確定すべく、まずはどのくらいの占有空間が真空槽の外側に必要かを把握するため。光てこ系の光学系概念図をつくる。部品選定が未定の部分は両方に対応できるようにしておく。（光学素子の型番や素子間の距離も記入のこと）。（光源）→（レンズ）→viewport、、、といったものでよい。|| ||004 実装図へ落としこむ||20121112 ||Akutsu?|| || AI003の光学系概念図を、真空槽近くの置き場のスペースにあうように実装図に落としこむ（もしくは占有されるスペースをわりだす、くらいでもいいのかもしれません）これは、みんなであつまってちょっと議論が必要かもです。|| ||005 CADへ反映||20121112 ||????|| || AI004の結果を、台座、足場ふくめてCADに反映|| ---- <> == Scope == . The scope of optical levers is to sense local angular motions (pitch and yaw) of any mirrors supported by vibration isolation system and other suspended stuffs including suspeded optical benches. == Applicable Documents == . TBD; just see the links below. == General Description == === Naming Conventions === . TBD === Locations === * BS chamber * ITM chambers (X,Y) * ETM chambers (X,Y) * PRC chambers (PRC, PR2, PR3) * SRC chambers (SRC, SR2, SR3) * MC chambers (MC1, MC2...) == Requirements == * Sensor noise should be less than xxx. * Sensor's dynamic range should be greater than xxx. * At least horizontal degrees of freedom (X,Y) * Preferably a vertical sensor (Z) and side * The sensors have to be rigidly mounted on the ground so that these are useful for remembering the position of the mirror and recording the drifts. == Characteristics == . Each optical lever consists of an optical system, a frontend circuit, and a human interface software. . The optical system consists of the following parts: a light source, optical fibers, a focusing telescope, viewport windows, a detector, and pylons which support the focusing telescope and the detector. The frontend circuit is TBD. Maybe we need analog cables (and what kind of connector should we use?), whitening filters and antialiasing filters. Maybe the matrix circuit will be realized using the digital systems, but in commissioning phase, we will need analog matrix. . The human interface software is TBD, which shows the mirrors' dofs monitored by Optical Levers. === Light source === * SLD-MS-261-MP1-FC/APC-PMF (from SUPERLUM) * P = 1mW, approximately * lambda = 670 nm, typically. * A lab test with the collimator and focuser at NAOJ ([[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4478|JGW-T1504478-v1]]) . For the light source, proposed candidates are * superluminous LED (SLED) or * laser light source as LIGO. === Optical Fibers === . The optical fibers transmit the light from the source to the focusing telescope. === Focusing Telescopes === . TBD. Moving linear stage with micrometer and some optical components like collimators? === Viewport windows === . See also the [[../Viewport1|viewport subsystem]]. . It should be transparent for the light source wavelength. . There should be no wedge; otherwise the multiple spots of light would be problematic. . See [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=1231|JGW-T1201231, Effect due to viewports for optical lever (in Japanese)]] === Detectors === . The detector will be an ordinary quadruplet photocondutive circuit with QPD. The noise level at '''xxx''' Hz should be '''xxx''' m/Hz^2^ * [[KAGRA/Subgroups/AOS/DCQPDList|List of DC QPDs]] === Pylons === . The pylons must be designed. == Inspection plans == . TBD == Procurement process and plans == . TBD <> == Links == . Some of the LIGO documents listed below are '''NOT''' public; to access them, you may need your own LSC account. * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=22686|LIGO-M1000343, Advanced LIGO Review Committee Report: Test Mass Optical Lever FDR]] * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=15032|LIGO-T1000517, Optical levers Final Design Review for test masses, recycler mirrors and HAM optical benches]] * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70690|LIGO-G1100961, Long-Term Stability Test for aLIGO Optical Levers]] * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=418|JGW-­G1100418, LCGT vacuum chamber envelope study]] * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=15271|LIGO-T1000533, Super-luminescent LED 21 and 50 day trend analysis]] * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=13338|LIGO-T1000390, Trade-off Study for the Optical Lever Light Source]] * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=11010|LIGO-T1000219, Test mass optical levers preliminary design]]