HIGH-PERFORMANCE SINGLE-MODE FIBER POLARIZATION-INDEPENDENT ISOLATORS

The design and performance of polarization-independent isolators that are substantially insensitive to variations of temperature and wavelength are presented. Three single-mode fiber isolators have been designed, constructed, and tested. The first isolator is a 1.3-μm two-stage isolator that has more than 40 dB of isolation and less than 2.0 dB of insertion loss over the temperature range of 15–70°C. The second isolator is a two-stage dual-wavelength isolator with an insertion loss of less than 4 dB and an isolation of better than 35 dB at 1.3 and 1.52 μm over the temperature range of 15–75°C. The third isolator is a three-stage isolator with an insertion loss of less than 2.5 dB and an isolation of better than 63 dB over the wavelength range 1275–1355 nm. © 1990 Optical Society of America.