A 100-ps Pulse Laser as a Calibration Source

We have developed a pulsed laser with a pulsewidth of 70 ps in the full-width at half-maximum as a light source for calibrating photon detectors. It has a simple electric circuit that generates short electric pulses that are applied to a laser diode. By utilizing the properties of the diode, a laser beam with a pulsewidth that is one-tenth of the applied electric pulse can be generated. Since the electric circuit is a simple shaping circuit, the pulsed laser can be generated at low cost, and the device can be made compact, occupying only a few cubic centimeters. Such short-pulsed-light sources are useful in high-energy experiments and astronomical observation as the time resolution and read-out electronics of the photon detectors are being continually advanced. The performance of this pulsed laser and its application for the calibration of photon detectors are reported in this paper.