| 摘要 |
PURPOSE:To set the optical pulse width at a certan value, by controlling the quantity of a phase circuit in accordance with a change of a DC bias current of a laser diode. CONSTITUTION:The pulse signal of the voltage EO is supplied to an NAND gate 2, and at the same time the signal of the same waveform which is delayed by time taud1 is supplied to the gate 2 via a phase circuit 1. The pulse signal having a width increased by taud1 through the gate 2 is applied to the base of a transistor TR33. The reference voltage VO is set lower than the voltage EO, and as a result the base potential of the TR33 is higher than the potential VO at a point A. Then the TR33 is turned on, and the current path of a constant current source 35 is switched toward the TR33. In this case, an amplified current having the same waveform as the control signal applied to the base is supplied to the collector of the TR33. While a current obtained by adding a bias current IB to the collector current of the TR33 is supplied to a laser diode 31. As a result, an optical output which has the same width as the input signal and is delayed by time taud1 to the current IB is oscillated from the diode 31. |
