Abstract: In an optical fiber assembly, an optical fiber having a core and a cladding is covered with a protecting film. The film is removed in a predetermined region extending from the end face of the optical fiber along the optical fiber, and the cladding is exposed. The surface of the exposed cladding is formed with a rough surface, and a laser beam which is transmitted to the cladding is scattered externally from the rough surface. The optical fiber is mounted on the hollow holder, and the rough surface of the cladding is disposed in the holder. The beam component scattered externally from the rough surface is absorbed by the light absorbing layer on the inner surface of the holder.

Abstract: Disclosed is a laser processing apparatus, which includes a falling waveform control circuit for controlling the falling of discharge current waveform. A direct current power supply circuit is connected to a main discharge circuit and the falling waveform control circuit for supplying discharge current to these circuits. The main control circuit causes the discharge of the main discharge circuit and falling waveform control circuit successively. The discharge of the main discharge circuit is provided so that it is stopped when the discharge of the falling waveform control circuit is started. The discharge of the falling waveform control circuit is stopped by a discharge current stopping circuit. The main discharge circuit and falling waveform control circuit are connected to a laser beam oscillating section.