1991—NIST begun offering routine calibration services for laser vacuum wavelength. Industrial users of laser interferometers need traceability of their measurements to national and international standards, and NIST measurements of the laser wavelength provide the critical link in achieving this traceability.
1993—NIST issued Standard Reference Material (SRM) 2520 for calibrating systems used to measure the geometry of optical fibers. NIST measurements are a key enabler of modern communications, which rely on lasers to transmit light signals through fiber-optic cables. Industry hit an early manufacturing barrier when optical fiber from different vendors could not interconnect without excessive signal loss due to lack of diameter control. NIST responded by developing SRM 2520, a short length of bare fiber in an aluminum housing, and fiber-optic test procedures for measuring diameter. In 1980, fiber cost $1 per meter and measurements constituted 20 percent of manufacturing cost; by 2005 the cost was down to 5 cents per meter and measurements were just 10 percent of manufacturing cost. NIST traceability enhanced competitiveness: An international study showed the United States had three times better diameter measurements than Europe and Asia.
1998—NIST researchers Sarah Gilbert and Bill Swann developed NIST Standard Reference Materials (SRMs) to provide accurate laser wavelength measurements. This work was critical to enable advances in wavelength division multiplexing (WDM), a technique for layering multiple signals over a single fiber for optical communications. These SRMs can also be used to calibrate optical spectrum analyzers and other test equipment with sub-picometer (trillionth of meter) accuracy.
1990s—The invention of ultrafast lasers, coupled with earlier work on laser stabilization, led to the creation of laser pulses short enough to produce "combs" of laser frequencies spanning the visible spectrum. (A shorter pulse produces a wider comb.) Optical frequency combs are key to the design of next-generation atomic clocks. Among NIST contributions, physicists Jan Hall and Steve Cundiff verified the idea of using microstructured "magic" fiber to produce white light composed of a supercontinuum of infrared, red, green and blue light—a comb of coherent optical frequencies.