Patent ID: 7733929

Claim:
A wavelength tunable optical transmitter, comprising: a single electroabsorption modulator integrated laser having an electroabsorption modulator and a semiconductor laser integrated on a substrate; a temperature control section for controlling a temperature of the electroabsorption modulator integrated laser and continuously outputting a device temperature corresponding to the temperature of the electroabsorption modulator integrated laser; a laser drive section for driving the semiconductor laser based on the device temperature output by the temperature control section, and for storing data of driving currents for an arbitrary temperature; and a modulator drive section for driving the electroabsorption modulator based on the device temperature output by the temperature control section, and for storing data of reverse voltages and voltage amplitudes for the arbitrary temperature, wherein said temperature control section changes the temperature of the electroabsorption modulator integrated laser so that an oscillation wavelength of the semiconductor laser is made tunable within a wavelength range of 3 nm or more; and wherein said laser drive section and said modulator drive section drive a driving current of the semiconductor laser and reverse voltage and amplitude voltage of the electroabsorption modulator continuously and respectively such that the electroabsorption modulator integrated laser has approximately the same optical output, modulation and transmission characteristics in the predetermined wavelength range.