Bilateral optical fiber power meter linearity comparison between NMIJ and NIST

Optical fiber power meter (OFPM) linearity standards of NMIJ (Japan) and NIST (USA) are compared using a commercial OFPM as a transfer standard at 1310 nm and 1550 nm over a power range [-60 dBm, 0 dBm]. At both wavelengths the comparison indicates an agreement between the two laboratories within the combined uncertainty. At 1550 nm the uncertainties are larger, which is attributed to unstable operation of the transfer standard at this wavelength.