IMPROVED OPTICAL FIBER POWER MEASUREMENT SERVICES AT NIST.

The optical fiber power measurement services provided by NIST have recently undergone substantial enhancement to better support the needs of the optical telecommunications industry and other users of optical fiber power meters. Absolute responsivity calibrations of optical fiber power meters are now offered by NIST at the following fixed nominal wavelengths: 670 nm, 780 nm, 850 nm, 980 nm, 1300 nm, and 1550 nm using any of the following connector types: FC/PC, FC/APC, ST, SC, E2000, SMA, and biconic. For special applications, tunable lasers are used to provide calibrations over limited wavelength ranges around 850 nm, 1300 nm, and 1550 nm as well. Measurement traceability for these calibrations now stems from a laser-optimized, cryogenic radiometer primary standard developed by NIST, and has enabled a reduction in measurement uncertainty to 0.5 % or less for typical absolute power calibrations. Linearity measurement services at 850 nm, 1300 nm, and 1550 nm also have been added to the calibrations offered for optical fiber power meters. The linearity measurements are performed using a NIST-developed, fiber and shutter system to implement a "triplet superposition" method of establishing detector response as a function of incident optical power. Formal internal NIST reviews of both the absolute power and the power linearity measurement systems recently were completed to assure that the highest possible quality and accuracy was being provided in these measurement services.