N211-094 TITLE: Compact Phase Locked Laser System for Atom Interferometric Inertial Sensors
RT&L FOCUS AREA(S): Nuclear Modernization
TECHNOLOGY AREA(S): Electronics; Materials / Processes; Sensors
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.
OBJECTIVE: Develop a compact and low power laser system capable of agile generation of all light frequencies required in an atom interferometry application. Demonstrate that the lifetime of all lasers in the optical system is sufficient to support extended periods of operation before required maintenance, and characterize robustness of the system to shock and vibration input.
DESCRIPTION: Light pulse atom interferometry (LPAI) [Ref 1] has been used to perform the most sensitive inertial measurements to date. It is emerging as a candidate technology for inertial sensors (such as gravimeters, accelerometers, and gyroscopes) with unprecedented performance. One obstacle for the development of atom interferometers is the need for further development of compact, robust, and stable laser systems that are capable of producing the requisite laser frequencies for LPAI as well as performing the ancillary functions of atom cooling, state preparation, and state readout.
Compact and robust laser systems for atom interferometry will facilitate the adoption of this technology in multiple application areas including inertial guidance and navigation and gravity mapping. Shipboard navigation using gravity measurements [Ref 2] to aid a traditional inertial navigation system is a typical use case. These systems may also find use in geophysical surveys for resource exploration.
These systems must also have the capability for fast frequency adjustment and shuttering on microsecond timescales. One promising approach is to perform these functions using a number of separate laser sources (such as Distributed Feed Back (DFB)) that are mutually offset-phase locked to a frequency stabilized master laser. The use of agile phase locking enables each output frequency to be adjusted throughout the measurement cycle while enabling the generation of phase-stable Raman pairs for LPAI while reducing the reliance on optical modulators that can be a driver of system power consumption. The Navy�s need is the further development and testing of compact phase-locked laser sources to ensure they can maintain sufficient phase stability for LPAI, can be tuned over 1 GHz repeatedly in a measurement cycle, support long laser lifetimes, and are capable of recovery from shock and vibration.
PHASE I: Develop a design for a compact laser system meeting the following requirements:
� Master laser locked to a saturated absorption feature of an alkali D line
� Two slave lasers phase locked to the master with offsets ranging from 0 to 5GHz
� Over 50 mW output power in each frequency component
� Capable of switching between multiple offset frequencies with switching time under 1ms
� Volume of optical module under 50 c.c. (not including drive electronics)
� Power consumption under 3W
Perform a study of laser lifetimes using laser sources similar to those in the proposed design. Develop a roadmap for achieving system lifetime over 50000 hours. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.
PHASE II: Build a prototype laser module with support electronics meeting the requirements for the design developed in Phase I. Characterize per MIL-STD-810 [Ref 3] for the response of the module to mild vibration and shock inputs. Perform a study of laser lifetimes using similar laser sources to characterize the expected lifetime of the module. Deliver the prototype by the end of Phase II.
PHASE III DUAL USE APPLICATIONS: Compact and robust laser systems for atom interferometry will facilitate the adoption of this technology in multiple application areas including inertial guidance and navigation and gravity mapping. Shipboard navigation using gravity measurements [Ref 2] to aid a traditional inertial navigation system is a typical use case. These systems may also find use in geophysical surveys for resource exploration.
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KEYWORDS: phase locked laser system; atom interferometry; inertial sensor; laser; navigation; image sensor