LASER DIODE DRIVING CIRCUIT, OPTICAL TRANSMITTING DEVICE, LIGHT TRANSMISSION SYSTEM AND LIGHT TRANSMISSION DEVICE

PROBLEM TO BE SOLVED: To improve the frequency characteristics of an LD module for optical transmission and widen the frequency band of an output optical signal. SOLUTION: When a voltage signal Vin is inputted into an electric signal input terminal 8, a high frequency component is enhanced in accordance with the resistance value RLD and the capacitance value CLD of a transistor 9, the LD module 3, and an equivalent circuit 13 thereof. The resistance value RLD and the capacitance value CLD of the equivalent circuit are set so as to be substantially the same as the resistance value and capacitance value of the LD module, whereby the output signal Vin1 at this time becomes the signal of frequency characteristics for correcting a deterioration caused by a resistance component and a capacitance component among the deteriorations of the high frequency component of output optical signal of the LD module. The voltage signal Vin1 is inputted into a field effect transistor 4 and is changed into a current signal I proportional to the signal Vin1 to drive the LD module. COPYRIGHT: (C)2005,JPO&NCIPI