Bay Photonics hits milestone in SIDEWINDER quantum project

Bay Photonics hits milestone in SIDEWINDER quantum project

The SIDEWINDER project, funded by Innovate UK, has the goal of developing a robust, industrialized, narrow linewidth laser for driving quantum processes. The role of Bay Photonics in the project is to take the breadboard laser prototype, created by the Fraunhofer Centre for Applied Photonics (F-CAP), and design a real world product and associated manufacturing process to ensure the laser can be produced in volume.

Under normal circumstances, Bay Photonics would send a team of experienced engineers to the client organization developing the prototype and spend several days de-constructing then re-constructing the prototype to establish a practical manufacturing process. Furthermore, we would use this visit to identify what precise manufacturing equipment would be needed on our manufacturing workstation. However, the SIDEWINDER project began in May of last year and although F-CAP, located in Glasgow, were able to design & characterize a successful prototype, national lock-down restrictions in Scotland meant that there was no opportunity for a Bay Photonics team to physically visit the F-CAP laboratories.

Of course, the project consortium were able to utilize video conferencing applications to allow a “virtual tour” of the laboratory, but to those of us who have experience building lasers, the prospect of remotely “tweaking” a laser cavity is somewhat daunting! To mitigate the complete lack of on-site exposure in Glasgow, the F-CAP provided a detailed written laser alignment process for the external cavity diode laser (ECDL) and a kit of parts was initially sent to consortium partner, Redwave Laboratories, who provide the control electronics for the laser. Being based in Oxford, the intention had been for a team from Bay Photonics to visit Redwave Labs to gain experience with the laser. Unfortunately, the imposition of the second national lock-down in England meant there could be no visit to the Oxford labs.

The consortium put “Plan C” into action and the laser was dis-assembled once more and sent to Bay Photonics in Devon. The parts arrived at our facility at the EPIC centre in Paignton in mid-March. Fortunately the detailed preparation made by the consortium ensured that the alignment workstation was well prepared, providing all the degrees of freedom required to position the optical components within the laser cavity within the sub-micron accuracy required.

It fell to Senior Process Engineer, Geoff Dumas (pictured with his alignment workstation at Bay Photonics), to get the laser up and running. “As well as the written alignment procedure, we had a number of online sessions between the consortium members to help get the laser set up, but we seemed to have hit a brick wall and we could not achieve lasing. But at the very end of the last session, we were given a “laser jock” tip that was not in the written procedure – and once the call was ended, I concentrated on that angle and within an hour I got the laser working.”

So despite the problems associated with Covid-19 lock-down, the SIDEWINDER consortium have worked closely together to ensure the project can progress successfully. Bay Photonics’ Research and Innovation Manager, Dr Andrew Robertson explains, “It is normally critical that we have time “on-site” to assess the optical system we are meant to be industrializing – but it was just not possible due to lock-down restrictions. We worked through the problem remotely, and with the full support of our partners we were able to achieve this key milestone, proving that our alignment workstation was suitable for the semi-automated alignment of the ECDL laser cavity. For those of us working in photonics, aligning a laser and seeing it spark into life is one of the most satisfying events. Now we can get onto the next phase of work which is taking the uncertainty out of the process and building a number of alpha-model lasers that will be shipped directly back to our partners F-CAP and Redwave Labs for characterization.”