| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a diffraction device which is small-sized and superior in mass-productivity and durability, can output two or more separated light beams in the same direction and which does not significantly change the propagation direction of diffracted light, even in the case of variation in operation environmental temperature. <P>SOLUTION: The diffraction device is constituted by forming one unevenly-sectioned diffraction grating as an incidence-side diffraction grating 102 on an incidence-side surface of a glass substrate which is a transparent substrate 101 and two diffraction gratings as light-emitting side diffraction gratings 103, 104 on a light-emitting side surface; and furthermore, the grating pitch of the incidence-side diffraction grating 102 is set equal to the grating pitch of the light-emitting side diffraction grating 104. <P>COPYRIGHT: (C)2009,JPO&INPIT |
