[8a-Z21-1~8] 3.2 Equipment optics and materials

[8a-Z21-4] Nano-Second Pulse Generation by Multiple Reflections on a Polygon-Mirror

Yuto Kojima¹, 〇Mitsunori Saito¹ (1.Ryukoku Univ.)

Keywords:Polygon mirror, Nano-second Pulse, Beam sweep

A laser beam was swept by a spinning polygon mirror to create nano-second pulses. When the mirror rotates with the angular velocity of ω=3,100 rad/s (500 revolutions/s), the angular velocity of the reflected beam is 2ω. If the reflection is repeated, the sweep velocity increases by 2ω on each reflection occasion. In the current experiment, the reflection was repeated eight times to attain the sweep velocity of 16ω=50,000 rad/s. Consequently, the linear velocity of the swept beam became 800 km/s at the distance of 16 m. As the beam moved across a photodetector, a signal pulse of 9 ns duration was detected.