DIGITAL OPTICS TECHNOLOGIES INC — Department of Defense STTR Phase I: AF20A-T002

Description

For navigation under GPS denied conditions, there is a need for inertial sensors, with better accuracy and smaller volume than the state of the art.  Over the last few years, with support from NASA, MDA, DARPA and AFOSR, and different branches of AFRL, we at Digital Optics Technologies (DOT), in partnership with Northwestern University (NU), have been developing a superluminal laser accelerometer and gyroscope (SLAG) that can improve the accuracy of rotation sensing and accelerometry by as much as six orders of magnitude.  Alternatively, for a give level of sensitivity, the SLAG can be very small.  The process that makes the SLAG so sensitive is critically tuned anomalous dispersion, corresponding to group velocity of light far exceeding the vacuum speed of light.  This is the so-called fast-light effect. This dispersion is produced by introducing a narrow dip in the gain profile.  This is made possible by using a combination of Raman gain in one isotope of Rb, and Raman depletion in another isotope of Rb, via careful juxtaposition of non-degenerate quantum transitions in these isotopes.  We have already built a portable SLAG, and demonstrated an enhancement in sensitivity by a factor of ~3000.  However, the current version is not optimized enough to achieve quantum noise limited sensitivity.  Under Phase I, we will improve the stability of the SLAG by employing a vacuum enclosed cavity using Invar, magnetic shielding, and better servos for temperature and pump laser frequencies, demonstrate quantum noise limited operation, and improve the factor of enhancement in sensitivity to be at least one hundred thousand.   This will establish the feasibility of using three SLAGs to realize a three-axes superluminal inertial measurement unit (SIMU) for GPS denied navigation.  In Phase II, we will combine three SLAGs, oriented orthogonally to one another, to realize a three-axes SIMU, within a volume of one liter (10 cm X 10 cm X 10 cm), with a sensitivity to rotation and acceleration that far exceeds, by a factor of as much as one hundred thousand, that of the state of the art IMUs, such as the Honeywell HG9900.  Two different directorates of AFRL, namely AFRL/RVSVC, and AFRL/RWWG, as well as MDA, NASA and DARPA, have supported the development of the SLAG technology previously, and are interested in potential usage of the SIMU for GPS denied navigation.  In addition, AFOSR has been currently supporting our work on developing chip-scale integrated photonic technology based components, for miniaturizing a broad range of sensors based on Rb.  Furthermore, Honeywell, Inc. has participated previously as a subcontractor during the early stages of the development of the SLAG, and is highly interested in helping us commercialize this technology.  We have two patents issued this year for the core technologies underlying the SLAG.  Prof. Selim Shahriar of NU, who is the inventor of the SLAG, will serve as the PI for this project.