Diode Laser Systems for Space-Based Cold Atom Clocks

ABSTRACT: We propose to combine distributed Bragg reflector (DBR) laser diodes with novel sideband locking schemes, MEMS atomic vapor cells, and offset phase locking to produce compact frequency-agile laser systems capable of autonomous operation on spaced-based platforms and remote environments. A master laser will output up to 40 mW of usable power and be locked to an atomic vapor cell forming an absolute wavelength reference on board the satellite. The slave laser will be offset locked to the master laser with agile detuning capability of up to 10 GHz, and with output power up to 200 mW using a DBR tapered laser or MOPA. By adding RF sidebands, the master laser can be used without a slave by virtue of a novel offset locking technique enabling production of cold-atom samples with a single laser. In phase I we will study the long-term aging characteristics of DBR diodes and their effects on long-term locking. We will also demonstrate novel sideband locking that can be used to eliminate the slave laser. In Phase II the laser system will be packaged into hermetic butterfly packages including MEMS atomic reference cells. Electronics drivers will enable completely autonomous operation BENEFIT: High power diode laser systems capable of reliable, agile, atomic locking will find uses in cold-atom spectroscopic sensors such as atom interferometers, gravimeters, magnetometers, atom clocks, focused ion beam sources and quantum computers. New inertial navigation sensors and atomic clocks are needed for GPS design environments. More accurate and lower power atomic clocks are needed for network synchronization for wireless networks and SONET. Cold-atom technology is also being used for the development of high-brightness ion beams useful for focused ion beams for semiconductor fabrication and electron beams for electron microscopy.