Shop our selection of wholesale optic attenuators. Perfect for FTTH and CATV networks. FS fixed and variable fiber optic attenuators with leading attenuating fibers guarantee consistent and stable fiber attenuation (0~60dB) in WDM transmission. Basic types of fixed attenuation include single mode, dual window and multimode in D4/PC, FC, FC/UPC, MU, SC, SC/APC and UPC, ST and ST/UPC style connectors. Optical attenuators usually work by. Optical fiber attenuators play a crucial role in optical communication systems, and their main function is to reduce the power of optical signals to prevent the receiver from being overloaded due to too strong signals.