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A simple and highly reliable laser system for cold atom experiments

Optics Communications 290 110-114 (2013)
D. Sahagun, V. Bolpasi, and W. von Klitzing
http://dx.doi.org/10.1016/j.optcom.2012.10.013 (local link)

Abstract:

The increasing complexity of cold atom experiments puts ever higher demands on the stability and reliability of its components. We present a laser system for atom cooling experiments, which is extremely reliable yet simple to construct and low-cost, thus forming an ideal basis for ultracold atom experiments such as Bose-Einstein condensation and degenerate Fermi gases. The extended cavity (master) diode and slave lasers remain locked over a period of months with a drift in absolute frequency well below 1MHz with a line-width of less than 300kHz. We generate the repumper light by modulating the current of an injection locked slave laser at a frequency of 6.6GHz. The construction of the laser is simple and largely based on off-the-shelf electronic and optomechanical components.

Design

The basic idea of this laser system is to keep the individual elements modular, so that a fault in one part of the system can be repaired by only changing the sub-system with zero changes elsewhere.  Each parts in the graph on the right thus represents a separate bread-board.
The article also describes a very simple diode laser with extraordinary long term stability (depicted here on the right). This master-laser uses simply to machine parts and a commercial mirror mount for holding the grating.  The diode holder and mirror mount are screwed onto an aluminium base plate, which is glued onto a Peltier element, which in turn is glued onto a base.  The whole assembly is then surrounded by thick-walled aluminium box, which has been lined with standard isolation foam.

Another key element are the distribution and AOM breadboards.  They consist of standard 40mm kitchen-top granite plates cut to 300x600mm.  The optical mounts are 1” aluminium posts which are glued onto the base plate using cyanoacrylate adhesive (Loctite 408).  The beam hight is 50mm.

Supplementary Material:

– Layout of the AOM board (including alignment procedure) (link)
– Layout of the distribution board (including alignment procedure) (link)
– Electronics Diagramms (link)
– Technical drawings of the master laser (link)
– Technical drawings of the slave laser (link)

Michael Morrissey

 09/2009 – 08/2011 Postdoc on BEC2

Before coming to Crete I graduated from Cork Insitutute of Technology (CIT) with a B.Sc. in “Applied Physics and Instrumentation” in 2004. As part of completeing the B.Sc. a five month project was undertaken. This project, entitled “Quality Surveillance Algorithms for Erbium Doped Fibre Amplifiers”, was carried out in the Information and Communication Network (ICN) Department at Siemens AG research facility in Munich. The project entailed research into how the aging of components with the EDFA can be monitored using algorithms. From a mathematical model, the key parameters needed to detect the degradation/aging of the EDFA were determined. In addition to theoretical work, optical experiments were carried out to determine a technique to measure the required parapeters. A procedure was developed to test the feasibility and accuracy of the EDFA model.

From my experience in Siemens AG, I developed an interest in optics and decided to pursue this interest. I started my PhD in September 2004 with the Quantum Optics Group under the supervision of Dr. Síle Nic Chormaic, in the area of “Control of cold rubidium atoms“.

I built the first cold atom experiment in South-Africa and then moved on to work at Extreme Light Infrastructure in Prague

Jules Grucker

11/2008 to 08/2009 Postdoc on BEC 2

Jules joined the Cretan Matter Waves group in Novembe 2008. He started in Sptember 2009 as a Maître de Conférences at the Université Pierre et Marie Curie and will do research at the École Normale Supérieure in Paris. He did his undergraduate degree in physics at University Strasbourg 1. He then went with an Erasmus scholarship to do his first Master degree at the Niels Bohr Institute, Copenhagen, Denmark. After this he returned to France to do a second Master degree, this time at the the Université Pierre et Marie Curie in Paris under the supervision of Paul Indelicato (currently director of Laboratoire Kastler BrosselEcole Normale Supérieure). For his PhD he went to the Institute Galilée of the Laboratoire de Physique des Lasers (University Paris 13). There he joined the IOA (Interferometry and Optics with Atoms) team of Martial Ducloy. He stayed on for one more year as a post-doc before coming to Crete.

Jules is now a lecturer at the Laboratoire Kastler Brossel at Ecole Normale Superieur in Paris, where he studies the properties of solid Helium with the aim of demonstrating a super solid.

11/2008 to 08/2009 Postdoc at the Cretan Matter Waves group
05/2006 to 05/2008 PhD Student at the Institute Galilée of the Laboratoire de Physique
05/2001 to 05/2006 Undergraduate degree in physics at University Strasbourg 1