The JDSU 54TR series transponder integrates optics and electronics in an OC-48 (2.5 Gb/s) time division multiplexing (TDM) transponder module. Multisource agreement (MSA) compatible and designed for operation at 1310 and 1550 nm, it can be used across a variety of optical fiber systems. The bidirectional modules provide a SONET or SDH compliant interface between the SONET/SDH photonic physical layer and the electrical layer. Major components include distributed feedback (DFB) based optical transmitter; an Avalanche photodiode (APD) optical receiver with transimpedence amplifier (TIA); a microcontroller; a laser driver; and an integrated 16 signal mux/demux with clock and data recovery (CDR) circuitry. The transponder provides either 1310 or 1550 nm wavelengths and is available in an APD receiver configuration. It receives a 2488.32 Mb/s optical signal, converts it to an electrical signal, recovers the clock, and demultiplexes the data into sixteen 155 Mb/s differential low voltage positive emitter coupled logic (LVPECL) data signals. The transponder is available in LR-1 or LR-2 configurations.