| 摘要 |
Nonlinear optical effects, such as stimulated Brillouin scattering (SBS), limit the power density of an optical signal that can be launched into an optical fiber. The SBS threshold is increased by a triple frequency modulation scheme, wherein an optical source (1) is modulated by a low frequency sinusoid (5), e.g., 10-100 kHz, as well as an amplitude modulated high frequency signal (7), e.g., 6GHz. In addition, the optical beam is externally phase modulated (8) at a frequency which is not less than twice the frequency of the highest signal frequency being transmitted by the fiber, e.g. 2GHz for a CATV transmission.
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