Low-noise optical amplification unit with reflection of the pumping power.

摘要

The present invention relates to an optical low-noise amplifier (2) of the active-fiber type. containing a laser emitting substance (3) to be connected to an optical telecommunication fiber (1) and receiving light there from at the transmission wavelength, in which the active fiber (6) is also fed from a light source at a pumping wavelength and has a length corresponding to a partial absorption of the pumping light directly input therein, downstream of active fiber (6) a selective mirror element (8) being present which reflects the light at the pumping wavelength and is transparent to the transmission wavelength light; preferably the mirror element (8) consists of an optical demultiplexer (9) adapted to separate the transmission wavelength and the pumping wavelength on two output fibers (11, 12), a mirror (13) reflecting at least the pumping wavelength being present at the end of the fiber (7) carrying the pumping wavelength.