PURPOSE: To obtain the optical waveguide which has short overall length, makes adjustments with simple constitution and obtains low attenuation by arranging optical axes in parallel to each other and at an interval with the optical axis of a lens so that a parallel beam traveling from the lens to the AOM is directed to the active area of the AOM at the Bragg angle to the optical axes.
CONSTITUTION: On at least one side of the acoustooptic modulator(AOM), single lenses 2 and 3 are arranged on an optical axis parallel to the transmission axis of the AOM 1 and the optical waveguides 4-6 have their axes arranged in parallel to each other and at intervals from the optical axes of the lenses 2 and 3 so that parallel beams 14-17 traveling from the lenses 2 and 3 to the AOM 1 are directed to the active area of the AOM1 at the Bragg angle to the optical axes. Consequently, adjustment is made by an easy method and low attenuation is obtained.
MANFURETSUDO FUKUSU
UORUFUGANGU BURENETSUKE
BUIRUHERUMU DARUGATSUTSU
