A heated laser package generally includes a laser diode, a heating resistor and a transistor in a single laser package. The heating resistor and transistor form a heating circuit and may be located on a submount adjacent to the laser diode. The transistor is configured to control the drive current to the heating resistor and any additional heat generated by the transistor may contribute to the heating of the laser diode and thus increase the thermal efficiency of the system. The heated laser package may be used in a temperature controlled multi-channel transmitter optical subassembly (TOSA), which may be used in a multi-channel optical transceiver. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).