SOW_for_SRM_2031_FINAL.docx

STATEMENT OF WORK

TITLE: Optically Contacted Metal on Fused Silica for Standard Reference Material (SRM) 2031

LAB REQUESTING SERVICE: Material Measurement Laboratory

I. BACKGROUND INFORMATION

NIST has an immediate need to procure 20 units of optically-contacted metal-on-quartz for UV/visible Transmittance standard SRM 2031, covering the wavelength range from 250 nm to 635 nm. This procurement is necessary to replenish our SRM inventory sold by our Standards Reference Material Program (SRMP). NIST has exhausted its inventories of the SRM (2031b), which are now sold out. This SRM is produced by evaporating a metal coating onto fused silica and then optically contacting another piece of fused silica onto the metal. In the past, we had acquired the fused silica with metal coating from an outside company and then used the NIST shops to perform the optical contacting. The difficult process of optically contacting metal to fused silica is no longer available through the NIST shops and it was also not available commercially until quite recently. Optiglas Ltd., through Starna Cells, Inc., has recently offered a commercial version of SRM 2031, which is optically contacted. We have tested these materials and have found them to be consistent with the specifications necessary for producing the SRM. We have tested metal coatings on silica, which were protected with an additional coating (e.g., silicon dioxide) or with no coating at all. We have found the optical contacting of fused silica to be the only form of protection that makes the material robust and homogenous enough to produce the quality and specifications needed for SRM 2031. These specifications include homogeneity to 0.8 % over a 32 mm2 area, robustness such that the filters are highly scratch resistant and their Transmittance values change by less than 0.5 % after repeated wet cleaning with methanol and lens paper, and stability of Transmittance over a 6 month period.

II. SCOPE OF WORK

The Contractor shall provide three optical filters made of optically contacted metal on fused silica. The three filters will have nominal Transmittance values of 10%, 30% and 90% for 500 nm light, and must meet the following specifications:

a. Physical Dimensions: 30.3 mm x 10.4 mm x 3.0 mm

b. Material:

10% Filter: Two fused silica substrates, one substrate (30.3 mm x 10.4 mm x 1.5 mm) coated with metal (chromium or inconel) and the other substrate (30.3 mm x 10.4 mm x 1.5 mm) optically contacted to the metal coating. The coating must completely cover one face of the substrate. Transmittance must be 10% at 500 nm and within the range of 6.5% to 14.5% over the spectral range of 250 nm to 635 nm. Transmittance must be homogeneous to 0.8% relative over an area 2mm wide by 16 mm long located in the center of the substrate.

30% Filter: Two fused silica substrates, one substrate (30.3 mm x 10.4 mm x 1.5 mm) coated with metal (chromium or inconel) and the other substrate (30.3 mm x 10.4 mm x 1.5 mm) optically contacted to the metal coating. The coating must completely cover one face of the substrate. Transmittance must be 30% at 500 nm and within the range of 25% to 40% over the spectral range of 250 nm to 635 nm. Transmittance must be homogeneous to 0.8% relative over an area 2mm wide by 16 mm long located in the center of the substrate.

90% Filter: One fused silica substrate (30.3 mm x 10.4 mm x 3.0 mm). Transmittance must be 90% over the spectral range of 250 nm to 635 nm. Transmittance must be homogeneous to 0.8% relative over an area 2mm wide by 16 mm long located in the center of the substrate.

c. Quantity: 20 pieces of 10% filter, 20 pieces of 30% filter, 20 pieces of 90% filter

III. PERIOD OF PERFORMANCE

The period of performance shall be two (2) weeks from award of this requirement.

IV. PLACE OF PERFORMANCE

All work shall be accomplished at the contractor’s facility.

V. GOVERNMENT FURNISHED PROPERTY

None

VI. DELIVERABLES

VII. ACCEPTANCE CRITERIA

NIST will test the metal on fused silica to confirm that it complies with the specifications in section II of this statement of work. These specifications include homogeneity to 0.8 % over a 32 mm2 area, robustness such that the filters are highly scratch resistant and their Transmittance values change by less than 0.5 % after repeated wet cleaning with methanol and lens paper.

Warranty: Warranty shall cover Stability of Transmittance over a 6-month period.

Packaging/Marking: SRMs are made of glass and should therefore be marked FRAGILE. They shall also be packed to prevent breakage.

Freight/Shipping Charges: Standard shipping charges apply to this requirement.

VIII. ACCEPTANCE CRITERIA AND PAYMENT

SRM materials must meet the required specifications. Measurements must be taken at the contractor site during production and at NIST after production to ensure that specifications are met. These specifications include 1) homogeneity to 0.8 % over a 32 mm2 area, 2) robustness such that the filters are highly scratch resistant, and 3) Transmittance values that change by less than 0.5 % after repeated wet cleaning with methanol and lens paper. NIST has 10 business days to confirm that the deliverable meets the specifications.

Advance payment is not authorized. Payment will be made upon receipt and acceptance of the required deliverables.