2.02b SOW.pdf

431nm External Cavity Diode Laser and Atomic Beam Ovens Statement of Work

Clock Development Division, Precise Time Department U. S. Naval Observatory

1.0 BACKGROUND

The United States Naval Observatory (USNO) is the authoritative source of time for the Department of Defense. For this purpose the USNO’s Precise Time Department maintains an ensemble of high-performing atomic clocks that is used to generate precise time. Because of the lack of commercial vendors for the highest performing clocks, stocking the clock ensemble with systems based on cutting-edge technology requires that these systems be designed and built in-house.

2.0 SCOPE

Within the Precise Time Department, the Clock Development Division is investigating atomic clock technology using optical spectroscopy. USNO seeks to procure one 431 nanometer (nm) external cavity diode laser (ECDL) that is compact, stable, and robust. An ECDL system using an interference filter for feedback is the best technology for the USNO’s purpose.

Related to this research and development (R&D) project, current efforts are focused on investigating types of alkaline-earth optical clocks. AOSense, Inc. designed and built a cold strontium source and a cold calcium source (products Beam-RevC-Sr and Beam-RevC-Ca, respectively). In an effort to minimize downtime, USNO seeks to purchase replacement and redundant ovens for strontium and calcium projects. Three (3) strontium (Sr) ovens and two calcium (Ca) ovens are required to meet the USNO’s requirements.

The required specifications for these procurements are listed below.

3.0 REQUIREMENTS

The USNO seeks to procure:

3.1 One (1) AOSense 431nm ECDL with the following specifications:

a. Center wavelength: 430.895nm in vacuum.

b. Wavelength selection: must use interference filter for coarse wavelength selection.

c. Tuning range: the system must be able to tune continuously over a range of 10GHz about the center frequency (wavelength) without mode-hops.

d. Linewidth: <500kHz averaged over 10ms.

e. Linewidth narrowing capability: actuator feedback with high enough bandwidth to reduce phase noise and narrow linewidth to ~10Hz. This can be direct connection to diode at laser head or external input to laser controller.

f. Output power: 60mW or greater.

g. Controller: controller for full operation of ECDL (current, PZT, temperature control) must be provided, with ability to feedback to current, piezo (PZT) voltage, and temperature using analog voltage (current, PZT) and computer (current, PZT, temperature) control.

h. Turnkey: the system must be provided with all parts to enable “turnkey” operation and achieve the specified performance in a typical laboratory environment.

3.2 Three (3) AOSense Strontium atomic beam ovens with the following specifications:

a. Three (3) ovens with heat shields.

b. Ovens must be compatible with Beam-RevC-Sr (product of AOSense, Inc.).

c. Each oven must be loaded by the vendor with a minimum of 5g of strontium.

d. Each oven must be able to heat Sr to > 530◦C and run continuously at 500◦C or higher.

e. Each oven must be able to generate a flux corresponding to 100% absorption of resonant

461nm light across the atomic beam at 500◦C.

f. Ovens must be shipped under vacuum in a storage chamber including angle valve and ion pump.

g. Ion pump controller and cable must be included.

h. Ovens must have the ability to be removed from storage chamber one at a time, while keeping any remaining ovens under vacuum (i.e. gate valves placed between oven sections in storage chamber).

i. Assembly and bakeout performed by the vendor.

j. Oven must have the ability to be installed into the Beam-RevC-Sr by USNO staff.

3.3 Two (2) AOSense Calcium atomic beam ovens with the following specifications:

a. Two (2) ovens with heat shields.

b. Ovens must be compatible with Beam-RevC-Ca (product of AOSense, Inc.).

c. Each oven must be loaded by the vendor with a minimum of 5g of calcium.

d. Each oven must be able to heat Ca to > 670◦C and run continuously at 600◦C or higher.

e. Each oven must be able to generate a flux corresponding to 100% absorption of resonant423nm light across the atomic beam at 600◦C.

f. Ovens must be shipped under vacuum in a storage chamber including angle valve and ion pump.

g. Ion pump controller and cable must be included.

h. Ovens must have the ability to be removed from storage chamber one at a time, while keeping any remaining ovens under vacuum (i.e. gate valves placed between oven sections in storage chamber).

i. Assembly and bakeout performed by vendor.

j. Oven must have the ability to be installed into the Beam-RevC-Ca by USNO staff.

4.0 FACILITIES, EQUIPMENT, AND TRAVEL:

Planning and support for the completion of these tasks will be coordinated with the technical POCs listed below for the USNO.

5.0 REPORTS TO USNO:

Contractor shall provide a final report regarding the completion and status of the ECDL.

Dissemination control of output products such as documents: The output products of the study shall be considered “DISTRIBUTION D: DOD AND DOD CONTRACTORS ONLY”, and shall not be further disseminated without written permission of USNO. Contractor shall comply with all relevant USNO, Navy, DoD dissemination, security and information assurance rules.

5.1 Acceptance and Quality Assurance

The contractor shall present final report(s) to the USNO technical POC for acceptance. The USNO technical lead shall address any issues that may arise during the execution of this contract.

6.0 PERIOD OF PERFORMANCE:

The period of performance is four (4) months or sooner for the delivery of components from award date.

8.0 PLACE OF PERFORMANCE:

US Naval Observatory 3450 Massachusetts Ave NW, Washington, DC 20392

6.0 PERIOD OF PERFORMANCE: