OPTICAL TRANSMITTER

PROBLEM TO BE SOLVED: To provide a technique whereby there are suppressed the wavelength variation caused by the temperature difference between an LD light emitting element 1 and a temperature sensing element 2 mounted in an LD module and the wavelength variation caused by the temperature dependency possessed by the temperature sensing element 2 itself, in order to realize a highly accurate wavelength stability required in the optical transmission method using a DWDM (Dense Wavelength Division Multiplexing) technique. SOLUTION: In an ATC (Automatic Temperature Control) circuit using a TEC (Thermo Electric Cooler), a temperature compensating portion 5 is so constituted while providing it connectively between a temperature sensing element 2 and a comparator 7 that it has the reverse characteristic to the wavelength variation of an optical transmitter. Thereby, the temperature difference between the obtained temperature information existent in an LD module from the temperature sensing element 2 and the temperature of an LD light emitting element 1 is so compensated as to realize a highly accurate wavelength stability. COPYRIGHT: (C)2005,JPO&NCIPI