| 摘要 |
An optical transmitter, suitable for use in digital optical communications for launching optical signals into optical fibres, and comprising a light source (1) for emitting a continuous light beam and an external modulator (6). The external modulator (6) comprises a beam splitter (2) for splitting the continuous light beam into two component beams; two electrodes (3-1, 3-2) which are respectively arranged for modulating the two component beams; an intensity modulation driver (4) for generating a voltage signal to be applied to at least one of the electrodes (3-1 in the Figure) to perform intensity modulation; and a phase modulation driver (5) for generating a further voltage signal to be applied in phase to both electrodes (3-1, 3-2) to perform phase modulation. Stimulated Brillouin scattering (SBS), which tends to be produced in optical fibres at high light powers, can thus be avoided without having to modulate the drive current of the light source (1). |
