| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical axis composite element causing no astigmatism and to provide an optical pickup using the same. <P>SOLUTION: In an optical system constituted of a two wavelength laser 12 having two light sources disposed with a prescribed interval, a collimator lens 4 in which light emitted by the two wavelength laser 12 and having two different wavelengths is made incident and which turns the resultant light to parallel light and the optical axis composite element 13 by which the optical axis of the light having the two different wavelengths is made to be the same mono axis, first and second reflection films 14 and 15 are formed on both surfaces of a transparent substrate 16 made of glass and the like worked in a prescribed plate thickness. The first reflection film 14 functions so as to reflect light having a first wavelength and to transmit light having a second wavelength and the second reflection film 15 functions so as to transmit the light having the first wavelength and to reflect the light having the second wavelength. <P>COPYRIGHT: (C)2008,JPO&INPIT |
