<P>PROBLEM TO BE SOLVED: To improve output eye quality without enlarging a device. <P>SOLUTION: A laser transmitter 10 includes an input stage 12, a limiting amplifier 14, an amplitude/common mode control circuit 16, a laser driver 18 and a laser diode 20. The input stage 12 generates second signals Vin<SP>+</SP>, Vin<SP>-</SP>having stable voltage variations in response to received first signals IN<SP>+</SP>, IN<SP>-</SP>. The limiting amplifier 14 outputs, in response to the inputted second signals, third signals Vout<SP>+</SP>, Vout<SP>-</SP>having improved rising and falling times and amplitude characteristics regulated by a control signal outputted from the control circuit 16. The laser driver 18 generates a fourth signal in response to the inputted third signals and the laser diode 20 is emitted on the basis of the fourth signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI 
EYE DIAGRAM IMPROVING METHOD FOR LASER TRANSMITTER