Patent ID: 6934078
Filing Date: 2005-08-23
Classification: H01S

Abstract:
1. A dispersion-compensated erbium-doped fiber amplifier comprising: a first fiber amplifying unit having a first erbium-doped fiber; a second fiber amplifying unit having a second erbium-doped fiber, arranged downstream from the first fiber amplifying unit while being connected in series to the first fiber amplifying unit; means for reusing a residual light, remaining after an amplification operation of the first fiber amplifying unit, as a pumping light for the second fiber amplifying unit; a fiber reflector for reflecting an optical signal amplified by the second fiber amplifying unit, thereby causing the reflected optical signal to flow backward towards the second fiber amplifying unit; a circulator for guiding the amplified optical signal, reflected to flow backward by the fiber reflector, to flow along a path different from that of the amplified optical signal applied to the circulator, while preventing an amplified spontaneous emission generated during an amplification operation of the second fiber amplifying unit from flowing backward towards the first fiber amplifying unit; a dispersion compensating fiber for dispersion-compensating the reflected optical signal, the dispersion compensating fiber being disposed between the circulator and the second fiber amplifying unit, and adapted to compensate for dispersion of the amplified optical signal, wherein, a signal-to-noise ratio based on Rayleigh back-scattering is maximized.