| 摘要 |
PURPOSE:To reduce crosstalk sufficiently by operating >=2 ultrasonic oscillators provided to an acoustooptic element alternately and outputting only generated diffracted light. CONSTITUTION:Parallel luminous flux from a rod lens 14 is diffracted by a diffraction grating formed by an ultrasonic oscillator 16 in the acoustooptic element 15 and propagates along an optical path 19 to enter an optical fiber 22 through a rod lens 21. Then, when the oscillator 16 is stopped and an oscillator 17 is put in operation, the diffracted light travels along an optical path 20 to enter an optical fiber 24. Therefore, the optical paths of the diffracted light are changed through the alternate operation of the oscillators and when there is not the diffracted light, no output is sent out, so the quenching ratio increases and crosstalk is made small. |
