The TRSL-5120G series single mode transceivers is small form factor, low power, high performance module for bi-directional serial optical data communications such as SONET OC-12 IR-1 / SDH STM-4 (S-4.1) and Fiber Channel. This module is designed for single mode fiber and operates at a nominal wavelength of 1310 nm. The transmitter section uses a multiple quantum well laser and is a class 1 laser compliant according to International Safety Standard IEC-60825. The receiver section uses an integrated InGaAs detector preamplifier (IDP) mounted in an optical header and a limiting post-amplifier IC. A PECL logic interface simplifies interface to external circuitry.