Welcome to gwoptics.org! These pages provide information and software related to gravitational wave detection, with a special focus on optics research. This page also hosts the outreach material of the Gravitational Wave Group Birmingham, UK, supporting the efforts by GEO 600 and the LIGO Scientific Collaboration.

A new window into the gravitational wave community

Finesse 2.0 is available now Finesse 2.0 is now available. More photos at http://gwoptics.tumblr.com/.

News

27.08.2014 - LIGO Magazine, issue 5, out now!

Once more, we are proud to announce the new issue of the LIGO Magazine. While members of the collaboration will be able to get their hands on a paper copy today, you can also download the magazine now! As usual the magazine provides insights into the different activities of the LIGO Scientific Collaboration, this time focussing on the life and work around the detector site in Louisiana.

LIGO Magazine issue5

05.06.2014 - Finesse 2.0 USB flash drive

Finesse USB flash drive

During the GWADW workshop in May 2014 in Japan we distributed USB flash drives to mark the release of Finesse 2.0. The USB drives contained the latest binaries along with a collection of documents (papers, notes and presentations) about Finesse that may be useful for those interested in optical simulations. Also included are Finesse input files for all the major gravitational wave detectors: Advanced LIGO, Advanced VIRGO, KAGRA, GEO600 and the Einstein Telescope, that you can experiment with. For those who did not attent the workshop we offer the USB drive image for download.

Finesse 2.0

21.05.2014 - Finesse 2.0 out now!

Almost one year after reaching version 1.0 we have now released a major upgrade of our interferometer simulation software Finesse. The upgrade included several long-requested feature, such as the possibility to model radiation pressure effects on suspended optics and to perform a full quantum noise analyses of interferometer output signals, including squeezed light and other quantum noise reduction techniques. The new program is coming with an updated manual and many new examples. See the Finesse download page for more information.

Finesse 2.0

19.03.2014 - LIGO Magazine, issue 4, out now!

The forth issue of the LIGO Magazine is out! With the magazine we try to provide insights into the different activities of the LIGO Scientific Collaboration. If you want to know more about gravitational waves or how large international science communties operate, download the magazine now!

LIGO Magazine issue4

28.01.2014 - PyKat, from Matlab to Python

Numerical modelling for the design or commissioning of laser interferometer often involves a series of related tasks. At some point it becomes more efficient to write scripts to automate the sequence of tasks. This has also the advantage of documenting the full activity from preparing the models to the post-processing of the result. So far we have used a set of Matlab tools (Simtools) to automate modelling with Finesse. Now are moving to Python using PyKat!

The move away from Matlab to Python has been on our To-Do list for a while. A big part of automating Finesse simulations consists of parsing and writing text files, for which Matlab is not ideal. More importantly Matlab licences can be very expensive so that many people cannot use our Matlab tools. Python, especially the interactive IPython, combines easy string handling with an intuitive interactive shell and the possibility to write reasonably elegant and readable script files.

PyKat has been written by Daniel Brown and is available as an open source Python package. It has already been used for serious work, the examples included in the package provide the results presented in the document: `Comparing Finesse simulations, analytical solutions and OSCAR simulations of Fabry-Perot alignment signals' (available for download: http://arxiv.org/abs/1401.5727). Try it out! Contributions and suggestions to the Python code are very welcome too!

Finesse 1.1

07.12.2013 - Modelling efforts

One of my favourite activities is to use numerical simulations to model real laser interferometers. The three links below show you some examples on what we have been working on during the last months.

Finesse Poster by Daniel Brown
Finesse 1.1

25.11.2013 - PhD positions available

Are you interested in advanced laser optics? Do you want to set up your own experiment, or would you like to contribute to one of the largest interferometer projects world-wide? Are you excited by porting numerical algorithms to GPUs and would you like to compare numerical models directly with experiments? We have PhD positions available now (start date October 2014, apply by 15. December 2013). For more information see our groups's PhD admission page and the project descriptions on my research page.

gwoptics

04.11.2013 - Finesse 1.1 has been released

A new version of Finesse is available for download. (You can also compile it directly from the source code.) The coupling of multiple frequency components has been completely rewritten. Now all laser fields and modulator sidebands are computed simultaneously (rather than sequentially as before). This change is a necessary preparation for the implementation of radiation pressure and quantum noise effect. It has the bonus feature of allowing the correct modelling of `sidebdands of sidebands' (such as created by two modulator components in series).

This is mostly a bug fixing release: We have changed a lot of the underlaying code, in preparation for the implementation of radiation pressure effects. This release marks the point in which all our tests produce the same results as before. For a full list of changes since version 1.0 see the file CHANGES.

Finesse 1.1

14.10.2013 - New paper

Today a new paper has been published on the arxiv.org server: < a href="http://arxiv.org/abs/1310.3120">Sensitivity of intra-cavity filtering schemes for detecting gravitational waves by Mengyao Wang et al.

Also, I realised that I never added a news item about our video paper! Already published in August, this is still worth a look: We demonstrate our recipe for creating pure, high-power ring-shaped laser beams:

Jove Video Paper, Screenshot
gwoptics

27.09.2013 - Finesse Syntax Highlighting

Recently some new files have been submitted by Finesse users Emil Schreiber and Will Vousden, so that Syntax Highlighting modes for Finesse are now available for Emacs, Vim, SublimeText (and TextMate, Textastic), Notepad++ and Ultraedit. You can download the necessary files from the GEO Simulation Group Wiki and of course Finesse from this page.

Finesse 1.0

25.09.2013 - The LIGO Magazine, issue 3

The third issue of the LIGO Magazine is out now! In this issue we bring you stories about the squeezing of light, a relatively recent concept from quantum optics, which might sound 'strange'. Hopefully the stories in the magazine will help to make squeezed light a little bit less strange. If you want to know more about gravitational waves and about what is going on in our community download the magazine now!

LIGO Magazine issue3

08.09.2013 - New plotting library for Processing

Our plotting library gwoptics for the Processing programming environment has been updated to version 0.5 and is now fully compatible with Processing 2.0. Give it a go, it also works on Android!

The library provides basic plotting functions for making 2D or 3D graphs with Processing. The examples included in the package show you how to plot data streams, data from lists or files or the output of equations.

Processing logo

10.08.2013 - Finding Black Holes with Lasers

In February 2013 I was invited by the Institute of Physics to give a lecture in the famous lecture theatre of the Royal Institution of Great Britain as part of their Physics in Perspective series. I was to expect about 400 students and teachers from schools across the country. The IOP has now published a recording of my presentation on youtube.

gwoptics

01.07.2013 - Testing, testing, testing ...

The main work behind the scenes of the release of Finesse 1.0 has been the testing, debugging and checking of the source code and of the simulation results. We are planning to collect this material and publish it as notes on the arxiv server. Today the first of these has arrived: Interferometer responses to gravitational waves: Comparing FINESSE simulations and analytical solutions by Charlotte Bond et al. It shows not only example Finesse results but also analytic solutions for simple interferometer responses - something we felt was lacking in the online literature.

fields at a mirror

06.06.2013 - Announcing Finesse 1.0

After more than 13 years of work and 25 releases we are proud to announce version 1.0 of the interferometer simulation tool Finesse!

Finesse is a fast and relatively easy to use software to simulate laser interferometers. It can be used for detector commissioning, interferometer design, or simply for learning more about laser optics. It is freely available for many platforms and fully open source. We also provide simple examples and an extensive manual.

Of course, we will continue to extend and improve Finesse. This version 1.0 completes the open source release of Finesse after a period of extensive testing and optimising the modeling of higher-order modes for beam shape changes and mirror surface distortions. The future of Finesse lies in the implementation of radiation pressure effects and quantum noise calculations; in fact, we have already started work on this.

Finesse 1.0

08.04.2013 - Recently published...

We have been quite busy recently and have submitted four new papers to the arxiv.org pre-print server. These papers provide a good glimpse into the work we do in our group, from investigating optical effects in detail to the design of future gravitational wave detectors. The pre-print server is open access, so have a look:

Polarisation diagram

D. Lodhia et al.: `Phase effects due to beam misalignment on diffraction gratings'
M. Wang et al.: `A realistic polarizing Sagnac [...] with DC readout for the Einstein Telescope'
L. Carbone et al.: `Generation of high-purity [...] Laguerre-Gauss beams at high laser power'
D. Brown et al.: `Invariance of waveguide grating mirrors to lateral displacement phase shifts'

20.03.2013 - The LIGO Magazine, issue 2

I am pleased to present the second issue of the LIGO Magazine! This issue of the magazine of the LIGO Scientific Collaboration (LSC) features articles about black holes, and the astrophysics and data analysis that LIGO can do to find out more about these elusive objects. We also include a mix of conference reports, news items and stories from the detector sites. If you want to know more about gravitational waves and about what is going on in our community download the magazine now!

LIGO Magazine issue2

18.01.2013 - Gravitational Waves in Korea

Our Korean colleagues have organized their first gravitational wave conference Gravitational Waves: New Frontier. The talks cover a wide range of existing and planned projects. The slides are available for download, have a look!

gwoptics

09.01.2013 - Stargazing Live in Birmingham

Today and on Saturday this week, we are taking part in a BBC Stargazing Live event on the University Birmingham campus. We are showing our exhibition Looking for Black Holes with lasers with a new addition: the Mirror Suspension model with the full Advanced LIGO BOSEMs and control electronics.

It's been a lot of fun so far with a great audience, see the queue in front of the Physics building.

gwoptics

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