NIST releases two new calibration standards for optical fiber communications. (Standard Reference Materials).NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. is releasing two artifact calibration standards relating to relating to relate prep → concernant relating to relate prep → bezüglich +gen, mit Bezug auf +acc polarization dependent measurements in optical fiber telecommunications applications. NIST will provide traceable measurements for polarization dependent loss (PDL See page description language. 1. PDL - Page Description Language. 2. PDL - Program Design Language. 3. PDL - Push Down List. 4. PDL - Dave Lebling, one of the co-authors of Zork. ) in optical fiber and fiber components, using an artifact standard made available to customers through a Measurement Assurance Program (MAP). A NIST scientist developed the artifact and will conduct the MAP. When PDL is combined with polarization-mode dispersion in a communication channel, the bit error rate is degraded. Therefore accurate measurements are necessary to enable high data rate communication systems. The MAP artifact consists of a short section of polarizing fiber spliced to a single mode input fiber and a step-index multimode output, and its PDL is certified over the 1535 nm to 1560 nm wavelength range. The artifact is implemented as a MAP [rather than a Standard Reference Material (SRM (1) (Storage Resource Management) The management of the storage resources in an organization in order to avoid duplication of files and to determine space utilization across all servers. )] to mitigate the degradation to uncertainty that is caused by exposure of the artifact to unpredictable temperatures. The MAP implementation includes a recording thermometer to indicate the temperature exposure of the device during tra nsportation and the customer measurement process. An additional SRM for polarization mode dispersion Polarization mode dispersion (PMD) is a form of modal dispersion where two different polarizations of light in a waveguide, which normally travel at the same speed, travel at different speeds due to random imperfections and asymmetries, causing random spreading of optical pulses. (PMD (Polarization Mode Dispersion) The type of dispersion that occurs in singlemode fiber due to a lack of perfect symmetry in the fiber and from external pressures on the cable. Light travels over singlemode fiber in two polarization states. ) will expand NIST traceability in this area. In an optical fiber communication system, propagation velocity depends on the polarization state of the light. The resulting PMD can broaden optical pulses Optical pulses Bursts of electromagnetic radiation of finite duration. Optical pulses are used to transmit information or to record the chronology of physical events. The simplest example is the photographic flash. and limit bit rate. The new SRM, developed by another NIST scientist, is SRM 2538, Polarization-Mode Dispersion, Non-Mode-Coupled. It is the second SRM for PMD. The first, SRM 2518, emulates the differential group delay in a long length of optical fiber. The new artifact, SRM 2538, is a fiber-pigtailed quartz plate, designed to Standard Reference Materials emulate the PMD typically found in telecommunications components. This new SRM is certified for mean differential group delay over a wavelength range of approximately 1250 nm to 1650 nm. SRM 2538 is certified for measurement by all PMD techniques (subject to instructions in the documentation). Due to technical constraints, SRM 2518 is certified for only a particular class of PMD measurement techniques. CONTACT: Paul Williams, (303) 497-3805; pwilliam@boulder.nist.gov. |
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