| 摘要 |
PURPOSE:To measure the temperature characteristic of a drive current simply and accurately by providing a system controller which includes a feedback circuit for holding the light output constant and a temperature controller for controlling the temperature of a constant-temperature oven. CONSTITUTION:A semiconductor laser 1 is filled in a constant-temperature oven 7, driven by a suitable current, and the laser is set to an accurate position while monitoring the light output by a photodetector 2. Then, the input current to the laser 1 is regulated through a system controller 4 so that a signal detected by a load resistor 3 becomes a desired light output. The temperature of the oven is set to the lowest temperature of the measuring temperature range, and raised at the certain constant rate. The light output from the laser 1 decreases when the temperature rises. Accordingly, to maintain the light output constant, the drive current is raised to control, and the temperature characteristic of the drive current is recorded simultaneously on the recorder 9. The temperature is raised, to the maximum limit temperature capable of maintaining the constant light output by the rise of the current, and the measurement is then finished. Thus, the temperature characteristic at the constant output drive time can be measured at one temperature scanning. |
