Statement_of_Work.pdf

STATEMENT OF WORK

TITLE: High-precision, high-speed wavelength meter

LAB REQUESTING SERVICE: Material Measurement Laboratory, Chemical Sciences

Division, Gas Sensing and Metrology Group

I. BACKGROUND INFORMATION

The Chemical Sciences Division Gas Sensing and Metrology Group (646.03) maintains primary measurement standards for monitoring trace levels of elemental mercury in atmospheric samples.

These standards are mandated by Environmental Protection Agency (EPA) regulations for monitoring and controlling emissions from power plants, cement plants and other industrial sources of airborne mercury. In an effort to expand the measurement range and speed, as well as to improve sensitivity, repeatability, and accuracy of our primary standards, Group 646.03 seeks to build a custom laser spectrometer for measuring mercury-in-air samples. Mercury has well-known absorption lines at wavelengths near 254 nm, with relatively strong absorption cross sections. NIST’s goal is to build a high-resolution laser spectrometer probing absorption in this wavelength range to measure mercury emissions from an existing standard mercury generator.

This new approach will provide a fast and sensitive alternative to conventional calibration methods based upon sorbent-trapping of mercury followed by inductively coupled mass spectrometry analysis.

II. SCOPE OF WORK

The planned measurements will use a single-frequency, continuous-wave (CW) laser to probe atomic transitions of the various isotopologues of mercury, the most important of which occur near

254 nm. Accurate determination of the mercury absorption spectrum will require a high-precision wavelength meter to measure the doubled wavelength of this probe laser beam. The laser source probing this mercury feature will be a frequency-quadrupled laser having emission also at 508 nm and 1116 nm. This spectrometer system will also be used to probe other absorbing species (such as ozone, water vapor etc.) over wavelengths ranging from the blue end of the visible spectrum and out to wavelengths into the near-infrared. Thus, the wavelength meter must operate over a spectral range from 400 nm to 1000 nm.

SPECIFICATIONS

Industry Terms understood by all vendors:

Wavelength resolution

Frequency resolution

Short wavelength cutoff

Long-wavelength cutoff

Update rate

Fiber coupling

Sensitivity

Continuous wave

The Contractor shall provide one wavelength meter with the following minimum technical requirements. The optical system must be fully integrated into a complete package. This should include a stabilized optical interferometer/fringe-counting system, an internal laser reference and single-mode fiber coupling for the laser. It must also be configured to accept an external reference laser. The device must measure the instantaneous wavelength of a continuous-wave laser beam over the range 400 nm to 1000 nm and must provide a digital output of the optical frequency (or equivalent wavelength), with a frequency resolution of 5 MHz or less, with an absolute accuracy of 10 MHz or less. The minimum required beam power shall not exceed 0.1 400 nm

System Requirements:

1. Wavelength meter spanning the wavelength range 400 nm to 1000 nm

2. Absolute accuracy 10 MHz or better.

3. Frequency precision, 5 MHz or better

4. Minimum required input power of 0.1 mW

5. Internal reference laser with an external reference option

6. Minimum update rate of 100 Hz.

7. The system footprint shall be less than 0.1 m2.

8. Fiber-coupled input.

Warranty:

The Contractor shall provide, at a minimum, a one year warranty for the equipment. The warranty shall cover all parts, labor and travel. The warranty shall commence upon acceptance by NIST of all required specifications.

III. PLACE OF PERFORMANCE

All work shall be completed at the Contractor’s facility. Equipment shall be delivered to NIST

Gaithersburg.

Installation of the instrument shall be accomplished by the Technical Point of Contact at NIST, Gaithersburg, Maryland.

IV. DELIVERABLES

Description Quantity Due Date

Fully integrated high-precision, high-speed wavelength meter

1 12 weeks after award of this requirement.

Manual detailing operation, trouble-shooting and maintenance.

1 12 weeks after award of this requirement.

V. ACCEPTANCE CRITERIA

The NIST Technical Point of Contact (TPOC) will perform acceptance tests to verify that all performance standards in this statement of work have been met. Acceptance tests, which will bc complete no later than 30 days after delivery, will include: 1) verifying the accuracy and precision of the wave-meter by reference to a NIST internal standard; 2) verifying that the minimum update rate (Requirement 6) is at least 100 Hz.