| 摘要 |
PURPOSE:To lessen the number of components, to reduce position adjustment of the components as much as possible and also to reduce the cost by a method wherein a laser diode chip emitting a laser light to enter each beam splitter is formed in a submount and installed on a plane whereon photodiodes for signal regeneration and monitoring are formed or at a position higher than the plane. CONSTITUTION:An N-type semiconductor substrate 16 is used as a submount in which an LD chip 1 is incorporated, P-type diffused regions are formed in two places within the same plane of this semiconductor substrate 16, and these regions are made to be a photodiode(PD) 14 for signal regeneration and PD 4 for monitoring. Besides, beam splitters 17 and 18 are installed on the PD 14 for signal regeneration of the semiconductor substrate 16 and incorporated in a stem 5. An emitted laser light from the LD chip 1 is split into a rectilinear light and a 90 deg.-reflected light by the beam splitter 17, and the rectilinear light is turned to be a 90 deg.-reflected light by the beam splitter 18, made to enter the PD 4 and used for control of the laser light. The reflected light at the beam splitter 17 is applied to a disk, and the reflected light turned to be a signal light enters the beam splitter 17 and then the PD 14, whereby a signal is regenerated. |
