Abstract: A pump light source includes a light emitting unit, a mode converter, and an optical interface unit. The light emitting unit is configured to output multi-mode pump light. The mode converter is configured to convert the multi-mode pump light output by the light emitting unit into a plurality of channels of single-mode pump light and output the plurality of channels of single-mode pump light. The optical interface unit is connected to an optical amplifier via an optical transmission medium to provide at least one channel of single-mode pump light in the plurality of channels of single-mode pump light for a corresponding optical amplifier via the optical transmission medium.

Abstract: Embodiments of an optical signal copier and an optical parametric amplifier are disclosed herein, which are applied to the communications field. In the embodiments, the optical signal copier is included in the optical parametric amplifier, which generates an invalid signal in a process of transmitting signal light and pump light. The optical signal copier may separate the signal light from the invalid signal and then transmit the signal light to a signal processing module. In this way, the signal processing module may directly process the signal light that does not include the invalid signal, the invalid signal does not occupy transmission bandwidth of the optical parametric amplifier, and the effective transmission bandwidth of the optical parametric amplifier is relatively large.