This is a sources sought notice for market research, not a solicitation, to identify vendors capable of supplying Optical Frequency Combs to NIST. Responses will help determine if a small business set-aside is possible, and all responsible sources including large and small businesses are encouraged to respond. Interested firms must submit a capability statement limited to four pages, including manufacturing origin, product specifications, and typical lead time. No budget amount or performance location is specified in the notice. No solicitation is currently available, and the government is not obligated to award a contract based on this notice.