| 摘要 |
PURPOSE:To oscillate a semiconductor laser in a stable wavelength even though the luminous which is made constant and the integral energy of the luminous pulse is changed by a method wherein bias current passed at the time of non-light emission of the semiconductor laser and the bias current is modulated by the pulse current of a duty ratio of D at high speed at the time of light emission. CONSTITUTION:When the waveheight value and the offset value of the pulse current are respectively set at IOP and IOS, the power consumption P2 at the time of light emission becomes P2=D.VOP.IOP+(1-D)VOP.IOS. This power consumption P2 must be naturally equal with the power consumption P3=VOP.Ib at the time of non-light emission, but if the D the IOP and the IOS are adjusted, the integral optical energy at the time of light emission can be changed without changing the P2. In this embodi ment, this semiconductor laser is driven in the pulse waveform on a condition of P2=P3. The luminous pulse of the pulse current waveheight value IOP on the right side is a luminous pulse having an integral optical energy smaller than that of the luminous pulse of the pulse current waveheight value IOP on the left side, and the waveheight value and the offset value of the pulse current are respectively changed into the IOP and the IOS, leaving the D intact so that the P2 is satisfied a constant condition. |
