| 摘要 |
PCT No. PCT/GB97/00505 Sec. 371 Date Mar. 11, 1998 Sec. 102(e) Date Mar. 11, 1998 PCT Filed Feb. 21, 1997 PCT Pub. No. WO97/36204 PCT Pub. Date Oct. 2, 1997A discrete electroabsorption modulator for optical signals has an electrical blocking region (12a, 12b) which is large as compared with the absorber region (13). The height of the blocking region (12a, 12b) is 3-20 mu m, e.g. 4-6 mu m and preferably about 5 mu m. In addition, the blocking region (12a, 12b) is 2-250 times, e.g. 15-25 times the height of the absorber region (13). The modulation depth is substantially increased, e.g. to values above 40 dB, by a thick electrical blocking region. It is believed that the thick blocking layer (12a, 12b) works because parasitic signals which escape into the blocking region are spatially removed from the vicinity of the absorber region; thus they are not acquired at the output. |
