FreezeRay (Compact laser cooled cold atom source)

Following the Nobel Prize winning discovery that lasers can cool atoms to extremely low temperatures there has been
extensive research into potential applications. Laboratory experiments with cold atoms have realised a step change of
approximately 1000 times improvement in both inertial navigation and in timing over conventional atomic clocks. These
Quantum Technologies (QT) are emerging to form a new market that will revolutionise many aspects of our daily lives. Cold
atom based QT devices are now forming the next generation of sensing equipment, including atomic clocks (satellite-free
navigation, finance and power synchronisation), gravimeters (military, underground and sub-surface detection) and secure
communications (banking and information exchange).
Each QT device will require a source of cold atoms. With a conventional approach the sub-systems required for producing
cold atom clouds typically occupy a large fraction of a laboratory. The creation and subsequent integration of these subsystems
also represents a significant time commitment, with experiments often requiring several months to a year before
achieving a sufficiently optimised cloud.
The excessive size and complexity of conventional systems will certainly hinder QT devices from exploring their complete
market potential. Achieving this will require a drastic improvement in the mobility of such systems, requiring them to
become smaller and more robust. This will facilitate QT devices becoming portable, allowing them to leave the laboratory
setting and to become technology rather than research apparatus. Furthermore, for QT devices to impact upon a diverse
range of markets it is necessary to commercialise and support the creation of a supply chain, driving down costs and
increasing reliability.
The aim of this project is to enable this through development of an "all-in-one" unit, the FreezeRay, which will be able to
function as the core engine for a variety of cold atom experiments. This will be achieved through advancement of a novel
all-fibre based laser system and the development of a small form factor vacuum system with limited pumping dependence.
The resulting integrated package will then form the centre point for numerous follow on QT devices or experiments.
To develop the FreezeRay engine we have formed a consortium of two industrial and one academic partners. The
University of Birmingham, Cold atoms group possesses a strong background in miniaturisation of cold atom systems,
through novel developments in vacuum and laser systems. UoB will apply their knowledge to the system design phase,
ensuring the design specifications will provide a cold atom source suitable for integration into QT devices. Gooch &
Housego will apply their world leading expertise in photonics to develop a fully fibre based laser system alongside the
control and stabilisation electronics. The laser system will employ frequency doubling of a telecom laser source. This allows
much of the system to be based upon telecom technology, reducing cost and improving reliability. e2v will use their strong
background in the development of small, self-contained vacuum cells to create a novel and compact vacuum system which
they will then integrate with the laser system. Following completion of the unit, UoB will characterise and evaluate the
system.

In addition to the short term economic benefits arising from the research market, the FreezeRay engine will become a key
component in future QT sensors, which will in turn give rise to an entirely new industry over the next 15 years, generating
major up and downstream benefits:
Economic: The project will help establish the UK as a major commercial supplier of atom cooling systems and provide
Europe with a supply chain outside the restrictions of ITAR. The system will also help reduce the cost for universities and
businesses entering into ultracold atom research. G&H will benefit by developing core stabilised laser technology and e2v
will benefit by developing sealed vacuum chamber technology. Both companies will benefit from spin off applications in
space and aviation.
The project will also facilitate the emergence of the QT market, the potential benefit being that it will broaden potential
applications, and therefore market potential. For example, improving the robustness and cost of QT devices will enable
them to enter markets such as construction, increasing their market potential by approximately £300m. Developments at
this level will also improve on underground asset location. Further reducing the cost of such systems will open markets
such as the gaming industry, with an estimated market for QT devices of up to £1bn.
Social: There are a number of social benefits that QT devices will enable over the next decades. For example, QT based
gravity sensing will allow monitoring of the water table leading to improvements in flooding prevention. In 2012, flood
damage cost the UK £4bn (BBC). Inland flooding causes an average of 133 deaths and $4bn in property losses p.a. in the
U.S. (National Weather Service). Natural disasters (glacier, volcano & tsunamis) can be predicted via highly accurate
seismic mapping. These areas are amongst the earliest benefits to be realised with an expected time scale of 5-10 years.
Other social benefits align with archaeology and the maintenance of cultural heritage where a step-change in geophysics
capabilities will revolutionise discovery processes.
The FreezeRay will aid University education into laser cooling, by allowing purchase of a system on which undergraduates
could perform practical work. This will be of even greater benefit to Universities which lack cold atom specialists among the
teaching staff. Lastly, 10-20 years from now, QT will make it into the classrooms and lecture theatres, educating future
scientists and engineers.
Environmental: There will be ground-breaking advances in earth observation, particularly in the measurement of water
distribution, where monitoring of the water table can be crucial in parts of the world where water shortages are prevalent or
where unregulated private bore-holes affect the local water table. The impact of natural disasters can be mitigated through
improved monitoring of flood alerts and also seismic activity for geological movement and earthquake, volcano and tsunami
predictions. In 2011, the Tohoku earthquake resulted in 20,000 deaths and massive economic losses. Estimated cost for
the clean-up operation in Fukushima Daiici is expected to exceed $250bn.