Laser interferometers are highly sensitive measuring instruments that use interference patterns from light waves to measure extremely small changes in length or displacement. They are used wherever high-precision measurement is required, such as in gravitational wave detection or in satellite missions for Earth gravity field observation, such as GRACE-FO, but also in research into quantum computers and other quantum technologies.
The setup of interferometers requires precise alignment of all individual components, as even the smallest misalignments can lead to significant errors in measurement. For this reason, experiments usually require complex adjustment procedures.
Gudrun Wanner from the Institute for Gravitational Physics at LUH and Tim Kaune from the MPI for Gravitational Physics have now released an extended IfoCAD software library, a tool that can simulate precision laser interferometry, considerably simplifying the design and operation of interferometers.
IfoCAD enables the geometry of the interferometer to be precisely planned using parametric inputs such as distances and angles, thereby facilitating the alignment and placement of beam splitters and photodiodes for optimum contrast. It can be used to analyse the different path lengths within the interferometer and ensure that they are either aligned with each other or with predefined values. IfoCAD can also help to minimise stray light, thereby increasing measurement accuracy.
An initial version of IfoCAD was released in 2009 by Gerhard Heinzel in the programming language C. The version now available builds on this version, but includes various enhancements made by members of the Institute for Gravitational Physics over the past few years and is now written in C++. It requires users to have the relevant programming skills.
Further information on IfoCAD and download options can be found on the website of the MPI for Gravitational Physics.
