PAssively STabilised Laser (PASTEL)

Cold atom-based quantum technologies have great potential because of the versatility of this platform. Cold atoms can be used in a variety of high-performance sensors, including optical clocks, inertial sensors, gravimeters, and magnetometers just to name a few. They rely on stable lasers with stringent requirements on their optical frequency. Recently, these quantum sensors began to be used in the harsh and dynamic environment of space, where inherent stability, reliability, size, weight and low power consumption are critical in determining the success of a mission, even more so than in terrestrial applications. In the PASTEL project we propose to develop and test a completely novel laser architecture that will improve on all the critical performance parameters indicated above over any competing laser technology. This new laser will be passively stabilised to an atomic reference within the laser itself. Our innovative approach eliminates the need for external frequency references and active feedback electronics. This development reduces the size and weight of both the laser module and associated electronics and lowers power consumption, while also improving stability and reliability since the laser cannot lose lock to a reference. We will exploit mature, power-efficient 780 nm diode laser technology, industry-leading miniaturisation and packaging capability, and compact, stable bespoke electronics. The aim is to have a breadboard system that proves the operation of the scheme and provides the basis for a future compact device development.