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All-optical diffractive element approach to compact, simple, rapid BEC creation in space

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United Kingdom
All-optical diffractive element approach to compact, simple, rapid BEC creation in space

First to build an optically streamlined, G-MOT system and sub-Doppler cool dense atomic clouds Then to load the dense ultracold atoms into a conservative optical dipole trap and evaporate to BEC


A crucial benefit of metrological experiments in space is the extended measurement time, which can only be fully utilized when using specially prepared ultra-cold atomic samples, Bose-Einstein condensates (BECs), having the minimum temperatures allowed by quantum mechanics. By utilizing a new method using Grating Magneto-Optical Traps (G-MOTs) which is fast, simple and compact, the generated BEC will be in an ideal format for space and terrestrial applications. An all-optical grating-based method provides a magnetic-field insensitive route to BEC, and in addition there is the potential for extension to simple optical lattice experiments which form the cornerstone of next generation quantum metrology and quantum computation. Future advanced metrological projects will be enabled: portable clocks and lattice clocks, magnetometers and atom interferometers. The utilization of G-MOTs with DipoleTrap-BECs (DT-BECs) combines two proven components into compact quantum technology. Laser cooled atomic samples have resulted in profound improvements in frequency metrology, however the technology is typically complex and bulky. Advances have been made in developing portable laser cooling apparatus, instilling the advantages of atoms in the micro-kelvin regime, as evidenced by on-going ESA projects in this area. However, simplifying the laser cooling procedures with micro-fabrication technology has, up to now, proved difficult. Micro-fabricated optical elements that greatly facilitate miniaturization of ultra-cold atom technology have recently been developed as part of a small ESA (TAS-TRP) project. Grating Magneto Optical Traps (MOTs) require only a single input beam-line, yet deliver 60 million cold Rb atoms from a cubic centimeter capture volume; comparable performance to an equivalent 6-beam trap and ten thousand times superior to prior micro-fabricated traps. Moreover, sub-Doppler temperatures can be reached in the same apparatus with similar total atom numbers, indicating the technology could be used for reaching high phase space densities ideal for creating quantum degenerate gases, or loading optical dipole traps and lattices. It is proposed to expand on this demonstrated diffractive optical technology towards a streamlined all-optical route to rapidly produce Bose-Einstein condensates (BECs) with a footprint and robust construction suitable for the first step to ultra-precision BEC atom interferometry in the harsh environment of space. This proposal represents the first phase of realizing this developmental vision, directly addressing the recent FTAP First Cycle recommendations (2012). Current high-repetition rate BEC experiments utilize two magneto-optical traps (MOTs), each requiring optical access along three perpendicular axes with five-six view-ports, and each fibered beam-line requires beam expansion and polarization optics. Moreover, magnetic chip traps typically require a vacuum-compatible electrical feed-through and specialized bonding. The same all-optical chip design offers a simple way to form phase-stable single-input-beam 3D optical lattices (for e.g. lattice clocks). These features, combined with simplicity of fabrication and operation, make this route to rapid BEC production a key advance in the development of high-accuracy, portable measurement devices.

Application Domain
Generic Technologies
Technology Domain
17 - Optoelectronics
Competence Domain
5-Radiofrequency & Optical Systems and Products
35-Technologies Enabling Breakthroughs in Science
Initial TRL
Target TRL
Achieved TRL
Public Document
Executive Summary