To obtain a semiconductor laser device or an optical transmission apparatus not requiring temperature control for keeping temperatures of the semiconductor laser element and an EA modulator or the like unchanged, and capable of providing a stable optical output in the semiconductor laser device using the EA modulator or in the optical transmission apparatus in relation to the semiconductor laser device for controlling a drive current of the semiconductor laser element, and controlling an optical output of the semiconductor laser element while monitoring a part of the output of the semiconductor laser element.
In the semiconductor laser device, there is disposed an optical absorber integrated photodiode 306, where an optical absorber having substantially the same temperature characteristic of optical absorption as that of an electric field type modulator is integrated, behind an electric field absorption type modulator integrated laser, and a laser drive current is controlled in response to an output current of the photodiode. As a result, the optical transmission apparatus obtained by combining the electric field absorption type modulator and the semiconductor laser element solves the problem that it is difficult to obtain a stable optical output unless temperature control is done.
NAOE KAZUHIKO
KAMIYAMA HIROYUKI
Kyosuke Tanaka