SLAC National Accelerator Laboratory, operated by Stanford University for the DOE, is seeking a U.S. domestic source to supply two linear diamond grating substrates with specified pitches, duty cycles, depths, and dimensions, plus two optional enhanced-depth items. The award will use a Lowest Price Technically Acceptable evaluation method, and offerors must be registered in the System for Award Management (SAM). The resulting purchase order will follow SLAC’s fixed-price commercial terms and conditions. Payment terms are Net 30 days, with freight terms FOB Destination Prepaid and Add. No budget amount or performance location is specified.