| 摘要 |
PURPOSE:To improve transmittivity and to improve efficiency by photoelectrically converting light reflected at an incident surface of the 2nd electroacoustic optical element of which incident light axis is aligned on the same straight line as the projected light axis of the 1st electroacoustic optical element. CONSTITUTION:Laser light from a laser light source 1 is made incident to the 1st electroacoustic optical element 2 in a case 7 and separated into the 0-th order light I10 and the primary light I11. The 0-th order light I10 goes straight on and is made incident to the 2nd electroacoustic optical element 3 and then separated into the 0-th order light I20 and the primary light I21. The 2nd element is ground so that the angle of the incident end surface of the 2nd element is set up to a prescribed value. A part of the 0-th order light I10 is reflected by the incident end surface, again reflected by a mirror 8 and then inputted to a photoelectric conversion element 5. The output of the 1st element is controlled by the photoelectrically converted output. Thus, the transmittivity and efficiency are improved with a simple structure. |
