In a perfectly aligned and matched Fabry-Perot cavity, one of the zero-crossings of an RF-demodulated error signal such as the PDH error signal corresponds to the cavity resonance peak. When imperfections are added, the two working points (peak resonance and zero-crossing of the error signal) can diverge. In this example we show how, a progressive […]
For an offset of about 1~5mW we can still lock the ITF in a working point, we know for a very small offset this does not holds i.e. 0.1mW, but when an offset of 0.2mW is selected it crashes.
For analysing the performance of a Mode Cleaner (MC) we need a “dirty” Beam as an input to make sure that our MC is filtering out higher order modes. To create a dirty beam we first add a laser to our system, than enable higher modes and add a mixture of new and higher order […]
The BS mirror in LIGO is considered not large enough. Therefore, Hiro mentioned that there was a calculation long time ago about the clipping loss at BS. The calculation was done with OSCAR and FINESSE, however, different result was found. So we want to use these simulation tools to do these calculation again. On my […]
Interestingly, the symbolic evaluation mentioned in the previous post now “just works”. Not sure what I did wrong. Here’s the updated snippet. Also, instead of the additional bp detectors, one can get to all the interesting bits directly from the trace output, e.g.
Investigating here whether the “simple” external solution with just one focussing element can work at all. Idea is that after BS, one would have a 45deg plane mirror to direct the beam some distance away to a focussing mirror, which produces a waist slightly before (or after) the PR/SR mirror, potentially with another folding mirror […]
Both keywords refer to the same action which fulfills the same task: to sweep over some parameter, to compute all the detector outputs, to return a solution object with its result, and finally to reset all the values it has changed during the sweep. The xaxis is used in KatScript command. It can be parsed […]
The position of CCD detectors seems to be only at nodes positions. It would be interesting to add an optional argument to move the camera a certain distance from the node to which it is attached to easily see the shape of the beam everywhere on the beam path.
The DC offset function (virgo.model.run(facV.DARM_RF_to_DC(dc_offset=0.001))) does not let to choose the direction of the offset which is applied (since it is applied on the power). It would be nice to have the possibility to choose the side of the offset applied
If the frequency response is done having as input the laser frequency it shows a bug. this can be solved if lf.AC is given as input in the frequency response