| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical filter with which a light translucent optical plate is easy to distinguish and manufacturing cost can be reduced. SOLUTION: The optical filter F1 is constituted of a quartz crystal wavelength plate 1, an infrared-absorbing glass plate 2 and a quartz crystal birefringent plate 3, and their main surfaces are stuck with an adhesive. Although it is not illustrated, an antireflection film (AR coated film) is formed on a light-emitting surface (rear surface) of the quartz crystal birefringent plate 3. Furthermore, the quartz crystal birefringent plate 3 has a profile size which differs from that of the quartz crystal wavelength plate 1 and the infrared-absorbing glass plate 2 and has an extension part 31, which extends in longitudinal directions (vertical directions). Additionally, a marking M is formed by laser, at the extension part 31 which is extended upward. COPYRIGHT: (C)2010,JPO&INPIT |
