| 摘要 |
PURPOSE:To reproduce pieces of independent information at the same time by semiconductor laser device which emits laser beams, and a disk record which has spiral tracks. CONSTITUTION:On an n type GaAs substrate (a), n type clad layers (b1)-(b4), n type active layers C1-C3, and an n type GaAs layer (d) are formed successively by capital crystal growth, and Zinc is diffused from part of the layer (d) to the layer (b1) to make part of each layer into a p type area; and a couple of electrodes (e) and (f) are formed in the n type and p type areas of the layer (d), which is removed between the electrodes. Forward currents are flowed to those electrodes to generate three laser beams at the same time and nearly in the same direction. A disk record has triple spiral tracks independent of one another, and on each track, independent information is recorded. Those tracks are irradiated with three laser beams generated by the semiconductor laser device constituted as mentioned above to detect their reflected beams by photoelectric sensors, thus reproducing three pieces of independent information simultaneously. |
