|
December,
2002
EEEL Researchers Complete International Intercomparison of Optical Fiber Power Measurements |
|
Igor Vayshenker, Xiaoyu Li, John Lehman, and David Livigni, EEEL researchers in the Optoelectronics Division, recently completed an international intercomparison of optical fiber power measurements with researchers from Physikalisch-Technische Bundesanstalt (PTB). This work, which has been submitted to Metrologia, is part of an ongoing effort to reduce the overall uncertainty of laser and optical fiber power meter (OFPM) calibrations.
Laser and optical fiber power measurements are the most frequently requested metrology service within the Optoelectronics Division and represent approximately one-half of the division’s calibration income. Customers of these services are primarily from the telecommunications industry, including telecommunications equipment manufacturers as well as manufacturers of test and measurement equipment.
This past summer, a novel NIST transfer standard based on germanium photodiodes was used in an intercomparison of OFPMs with PTB at nominal wavelengths of 1300 and 1550 nm (wavelengths at which most of the world’s optical-fiber based communication is transmitted). Measurement results showed differences of less than 1.5 parts in 103, well within the combined uncertainty for both laboratories, demonstrating that optical fiber power measurements from both laboratories are among the best in the world. The NIST transfer standard, developed as part of an ongoing effort to provide lower uncertainty for OFPM calibrations, has a coupling efficiency very near unity up to a numerical aperture (NA) of 0.26. This is very important for applications such as optical fiber where the light incident on the detector has a large angular divergence. The transfer standard can be calibrated directly against a primary standard with collimated radiation as well as be used to accurately measure optical power from a fiber, without intervening optics.
Contact:
Igor Vayshenker (303) 497-3394 |