| 摘要 |
PROBLEM TO BE SOLVED: To improve faults of a front-to-back ratio linearity of the essentiality of a semiconductor field absorption type modulator integrated laser of one of the important components of a main line optical transmission. SOLUTION: A monitoring current Ip, of the rear output of an EA(electroabsorption) modulator integrated laser 106, is electrically corrected by a nonlinear amplifier 402 to a current output, such as after passing the EA modulator similarly to the forward output, and a laser drive current source 103 is controlled, to suppress the current dependence of the front-to-back ratio. Accordingly, the rear monitoring current is converted into the nonlinear type, and this electrical signal is output as the laser drive current. Since the current is corrected by the semiconductor laser module and the optical transmission module mounting the nonlinear type, the optical output stability and reliability of the laser module and the transmission module are improved. |
