The National Institute of Standards and Technology (NIST) is seeking responses for a Sources Sought notice regarding the procurement of a low-noise and low-drift closed-loop cryogenic microscope system, which includes nanopositioners and a cryogenic high-NA optical objective. This system is critical for the Quantum Measurement Division's mission to develop high-efficiency deterministic single-photon sources for applications in quantum communications and scalable quantum computer networks. The procurement aims to enhance NIST's capabilities in studying single-photon and entangled light state generation, with specific technical requirements outlined for the system's performance and operational parameters. Interested parties should submit their responses, including company details and capabilities, to the primary contact, Cielo Ibarra, at cielo.ibarra@nist.gov, by the deadline of January 23, 2025, for any inquiries regarding the notice.