| 摘要 |
PURPOSE:To enhance the reliability of a laser diode and to eliminate the necessity of mechanically moving a laser reader by freely varying the light emitting section of the laser diode by applying electric control signal to the control electrode thereof. CONSTITUTION:A current flows from positive electrode 7 sequentially through regions 5-1 to negative electrode 6, and an active layer for emitting laser light in the P type region 3 having narrow gap energy Eg as compared with the regions 2, 4 is formed. The region 4 adjacent to the region 3 becoming the active layer is formed of P type semiconductor. Control electrodes 11, 13 for controlling the light emitting region in the region 3 through the insulating layers 10, 12 are provided on the side surface of the region 4. When positive potential is applied to the region 5 and zero potential is applied to the region 1, a current will flow from the region 5 to the region 1. The region 3 at this time has wide light emitting region in amplitude. A laser reader using such laser diode is unnecessary to mechanically move, and mechanical parts can be thus omitted so as to improve the reliability. |
