| 摘要 |
An opto-electrical modulator (20) is described which serves to control a directly modulated laser in the Gigahertz range. The modulator (20) comprises a laser (51), a beam splitter (52), two modulators (54, 55), an optical (59) and an electrical 90-degree hybrid (60), two photodiodes (65, 66) and two amplifiers (75, 76). The beam splitter (52) splits the first light beam (S1) emitted by the laser (51) into two sub-beams (S2, S3) of the same intensity. These sub-beams are intensity-modulated in the first modulator (55) by an auxiliary carrier signal (TS) or are phase-modulated in the second modulator (54) by a useful signal (NS). The resulting sub-beams (S4, S5) are mixed in the optical 90-degree hybrid (59), the emitted light beams (S6, S7) are converted by the photodiodes (65, 66) and the downstream amplifiers (75, 76) into electrical currents (i1, i2) and these are similarly mixed in the electrical 90-degree hybrid (60). This produces a time-variant current (i) at the output (23) whose auxiliary carrier is phase-modulated. The modulator (20) can be implemented as an integrated opto-electronic component. <IMAGE> |
