The product label shows it is Truewave-plus fiber, and it is made in December 1996. We fusion-spliced two FC/APC connectors with SMF-28e 3mm cable on fiber spool ends, splice loss is very low. The following message is from http://www.olson-technology.com/mr_fiber/Fiber_Types.htm NZ-DSF was developed to counteract the FWM limitations of DSF. The idea is to move ?0 to either end of the 1550 nm band, thus ensuring that all of the wavelength channels have slightly different optical speeds in the fiber. Common brands are TrueWave Classic (Lambda0 < 1530 nm), TrueWave Plus (Lambda0 = 1497 nm), TrueWave RS (Lambda0 < 1452 nm) by Lucent, and SMF-LS (Lambda0 > 1560 nm) by Corning. The advantage that these fibers have over DSF is a compromise solution of a slightly lower degree of integrated dispersion compensation for a higher tolerance to non-linear distortion effects. Available with positive dispersion (+D) NZ-DSF and negative dispersion (-D) NZ-DSF. The following message is from last pdf link below: -------------------------------------------------------------------------------------- The first generation of Truewave fiber was originally developed in 1993 by ATT. Since then, the Truewave family has evolved under the Lucent brand. After the TW-AT&T, the next member of the family was named Truewave Classic (TW-C). In the data sheet below, we notice a slightly higher CD coefficient and a slightly reduced dispersion slope compared to the TW-AT&T. Following the TW-C, Lucent introduced the Truewave Plus (TW+). Even in this case the CD properties have been modified. The rest of the optical parameters are left unchanged. The Truewave evolution continued with the introduction of major changes in the Truewave Reduced Slope (TW-RS), which, according to Lucent, represent the largest part of installed Truewave. The TW-RS is characterized by a higher CD and shows a decrease of about 36% in the dispersion slope. These two properties translate in a performance improvement for high-density DWDM applications. The latest member of Truewave family, the Truewave Reach, has been introduced in 2002. The TW Reach is a fiber optimized for application in the S, C and L band and for Raman assisted amplification. (The datasheet is currently not available). ---------------------------------------------------------------------------------------