| 摘要 |
<p>The optical pickup device provided with light generation means (1) for emitting a linearly polarized light to a recording medium (7) comprises: a first diffraction element (14) for diffracting a light reflected from the recording medium (7); a second diffraction element (15) for separating a first diffracted light from the first diffraction element (14) into a transmitted light and a first order diffracted light according to a polarization component of the first diffracted light; light receiving means (16, 17) for receiving the transmitted light and the first order diffracted light from the second diffraction element and converting them into electric signals. This optical pickup device is arranged such that grating pitches (14a, 14b, 15a, 15b) of the first and second diffraction elements (14, 15) are set so that an angle of incidence of the first diffracted light that is incident on the second diffraction element (15) from the first diffraction element (14) is equal to a Bragg angle of the second diffraction element (15). With this arrangement, an optical axis can be easily adjusted between the first diffraction element (14) and the second diffraction element (15). Moreover, if the first diffraction element (14) and the second diffraction element (15) are laminated together, an adjustment in the optical axis is no longer required. <IMAGE></p> |
