How to make a MICH scan outside virgo model?

We would like to make a MICH scan of the microscopic length for a generic interferometer. This was the Finesse 2 code func rev = (-1)*$x1 xaxis NI phi lin -10 10 500put NIAR phi $x1put WI phi $revput WIAR phi $rev noplot rev We tried with dof MICH NITM.phi -1 NETM.phi -1 WITM.phi +1 […]

Changing the Schnupp Asymmetry in the finesse-virgo model

This is a simple snippet of code showing how to change the Schnupp asymmetry in the finesse3 virgo model. The process is quite straightforward and is based on simply changing the length of the space between the beamsplitter and one of the compensation plates. An important step to follow the Schnupp asymmetry change is to […]

Gouy phase in a recycling cavity with one focussing element

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 […]

CCD position

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.

DC offset function

The DC offset function ( 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

Specifying arbitrary suspension plants

Arbitrary mechanical plants can be specified for each optic by giving a zpk description. The example below makes a simple Fabry-Perot cavity and specifies the longitudinal and pitch plants. First build the cavity The suspension plants are specified by defining dictionaries with the zpk definition of the plant. The code below defines a simple pendulum […]

Selecting Higher-Order Mode indices to model

Note: This post is based on the relevant Finesse 3 documentation page: Models in Finesse are, by default, created as plane-wave representations of the underlying configuration. This can be switched to a modal basis by specifying the mode indices that should be modelled by the system. There are a few key ways in which […]