The transmitter module is intended for use at SDH and SONET bit rates. The device meets the intention of the ITU-T (G.691) recommendations. The single silicon IC is used as a laser driver, modulator and automatic power control. To ensure a proper laser operation over the wide temperature range and life of operation, the average optical output power is controlled. The laser bias is externally accessible for monitoring of the performance. A power alarm is activated when the average optical power cannot be maintained within specification. A laser shut-down is also provided according to SDH/ SONET requirements.