2002 年 5 巻 3 号 p. 293-297
We present the results of the stray light noise suppression experiment in the laser diode (LD) /photo diode (PD) integrated units for optical pickup use. The use of dummy PD elements have proven to be effective in removing the diffusion current generated by the stray light. Because they can trap the stray light and re-combine the photo-generated carriers, multiplex reflection is avoided. Moreover, stray light irradiating photosensitive elements of the PD can be effectively prevented by establishing a partition between the LD and the photosensitive elements. Preliminary experiment shows that the partition installation lowered the noise level to less than 40% comparing with that of no partition.