High-bandwidth measurements are needed to support systems that take advantage of the potential bandwidth of optical fiber. Systems presently being installed operate at 5 to 10 gigabits per second using pure time-division multiplexing (TDM). Research is being done on the next generation of TDM systems at 40 gigabits per second and higher in laboratories around the world. Methods are needed to accurately characterize the scalar and vector frequency response of high-speed sources, detectors, and instrumentation to three to five times the system modulation rate. Burst-mode operation in asynchronous transfer mode networks requires additional characterization at very low frequencies. Increasingly tight tolerances in both digital and analog systems require frequency-response measurements with low uncertainty.

Measurements of source and detector noise are required to predict low bit-error rates in computer interconnects, and high carrier-to-noise ratios in analog systems, and to support measurements of the noise figure of optical amplifiers. The intensive use of laser target designators and range finders by the armed forces requires traceable calibration standards for low-level pulse peak power and energy at 1064 nm and 1550 nm.