| 摘要 |
PURPOSE:To measure the wavelength of each time at a variable wavelength semiconductor laser in a real time by composing it of means for varying an operating temperature, means for holding an injection current at a predetermined value to alter it to the predetermined value, and means for outputting an electric signal corresponding to a terminal voltage. CONSTITUTION:An injection current flowing to a semiconductor laser 1 is held at a predetermined value by a current stabilizer 2. This predetermined value is altered, for example, by varying the voltage, the current from a power source by a variable resistor, a changeover switch. The operating temperature of the laser 1 is altered by a thermoelectric element 3 and a current controller 4 for controlling the current flowing to the thermoelectric element 3. The terminal voltage of the laser 1 is amplified by an amplifier 5 to become an external voltage output. While the injection current remains constant, the operating temperature of the laser is swept by the thermoelectric element so that the oscillation wavelength becomes variable, thereby knowing the wavelength at each time from the terminal voltage in a real time. |
