The Department of Commerce, specifically the National Institute of Standards and Technology (NIST), is conducting a sources sought notice to identify potential sources for a microwave digital lock-in amplifier. This equipment is essential for measuring photonic test structures, which are critical for characterizing integrated photonic fabrication processes and materials, thereby addressing a significant metrology need in the integrated photonics industry. The amplifier must operate at frequencies of at least 1.8 GHz and meet specific technical specifications, including multiple independent channels and high-resolution capabilities. Interested vendors should submit their responses, including company information and product details, to the primary contact, Nina Lin, at nina.lin@nist.gov, preferably before the closing date, as this notice is for market research purposes and does not constitute a commitment to award a contract.