| 摘要 |
PCT No. PCT/GB91/00693 Sec. 371 Date Nov. 10, 1992 Sec. 102(e) Date Nov. 10, 1992 PCT Filed Apr. 30, 1991 PCT Pub. No. WO91/17571 PCT Pub. Date Nov. 14, 1991.The output of semiconductor optical sources is monitored by a photo detector including a photodiode having a photosensitivity which is less than the total active area of the device. Conveniently these active areas may be arranged in groups. The electrical output of selected areas or groups of areas or both may be arranged to be enabled or disabled as appropriate to provide the required photo responsivity of the device. |
