| 摘要 |
PURPOSE:To perform scanning of wide scanning width at a high speed by providing an anamorphic optical system in the optical path for the luminous flux deflected in a waveguide. CONSTITUTION:The luminous flux from a semiconductor laser 3 installed at the end face of a waveguide 2 is paralleled by a thin film lens 4, and the parallel fluxes are deflected by the surface acoustic waves deflected by a comb-tooth shaped electrode 6, and are condensed by a thin film lens 12. The focal length of the lens 12 is so selected that when the waveguide 2 is assumed to be infinitely long the exit luminous flux 13 focuses at the distance of Fa from the actual waveguide end face 14. In effect, the waveguide 2 is finite and therefore the luminous flux is condensed by refraction at the distance of Fb=Fa/n (n: refractive index of the waveguide). A cylindrical lens 15 is disposed in the optical path of the exit luminous flux from the end face of the waveguide. This lens 15 has no condensing effect within the plane of the waveguide (X-Z plane) and condenses the luminous flux in alignment to the condensing point 31 in the plane of the waveguide in the direction Y perpendicular to this. |
