Optical Lever (Room Temperature)
Related subgroups: VIS, IOO, MIF, VAC, CRY...
Contents
Scope
Sensing local motions including longitudinal dof and all alignment dofs (pitch, yaw and roll) of any mirrors supported by vibration isolation system.
Note on the operating temperature: here the system is assumed to be utilized at room temperature, not in cryogenic temperature.
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 a sensor part, a frontend circuit, and a human interface software.
The sensor part 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 show the mirrors' DoFs monitored by Optical Levers.
Light source
For the light source, proposed candidates are
- superluminous LED (SLED) or
- laser light source as LIGO.
Optical Fibers
Optical fibers
Focusing Telescopes
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.