[15a-C32-1~12] 3.8 Optical measurement, instrumentation, and sensor

[15a-C32-6] Ultrashort Pulsed-laser Beam Divergence Angle Measurement Using Simple Shearing Interferometer

〇YASUNORI IGASAKI¹, JUNJI OKUMA¹ (1.HAMAMATSU PHOTONICS)

Keywords:ultrashort pulsed-laser, interferometer, laser

We developed the simple sharing interferometer using two wedged substrates. Incident light is divided into four paths, and two of them interferes each other. Analyzing the interfered pattern, we can measure divergence angle of the incident light beam. The optical length difference between the two paths can be close to zero by adjusting incident light angle to the interferometer. Therefore, even if the coherence length of a light source is very short, such in case of an ultrashort pulsed-laser beam, the divergence angle can be measured. We explained the above fact both by simulation and experiment. We show results of divergence angle measurement of 100 fs ultrashort pulsed-laser beam.