| 摘要 |
PURPOSE:To realize an optical element whose production and adjustment of assembly are facilitated. CONSTITUTION:A recessed part having a triangular cross section is formed on a plane parallel plate 31. A projected part having triangular cross section is formed on the plane 50 of a plane parallel plate 32. Since a light beam transmitted through the vicinity of the ridgeline 43 of the plate 31, out of laser beams emitted from a laser diode 21, is refracted to the outside, a zone where the light beam does not exist in substance is formed in a zone A. |
