A microprocessor is used to control the temperature of a laser emitter and thereby regulate the wavelength of optical signals from the laser. A serial interface in the microprocessor provides input and output lines to a host device, and temperature lookup tables are stored in nonvolatile memory. Control logic processes information stored in the memory as well as information on operating conditions of the laser emitter to precisely control the temperature of the laser emitter. A thermo-electric cooler adjusts the temperature of the laser emitter.