An optical amplifier assembly and a detection method capable of dynamically performing optical time-domain reflection detection. The detection method comprises obtaining signal light intensity detection signals from a first and second photodetectors and sending a control signal to an L-band Raman pump when it is determined that the signal light intensity in the second photodetector is lower than a first preset threshold, so that the L-band Raman pump enters into an optical time-domain reflection detection mode; sending a control signal to the L-band Raman pump when the signal light intensity in the second photodetector is greater than or equal the first preset threshold, so that the L-band Raman pump enters into an L-Band Raman optical fiber amplifier operation mode.

An optical amplification system includes: a first amplification module configured to amplify at least a conventional band (C band) optical signal; a second amplification module configured to amplify a longer wavelength band (L band) optical signal; an attenuator configured to attenuate at least the C band optical signal to obtain a first optical signal and a second optical signal, where the attenuator is further configured to output the first optical signal to the second amplification module and output the second optical signal to a wavelength division multiplexing module, which is configured to combine and output the C band optical signal and the L band optical signal.

A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.

The present invention relates to the field of optical communication, and particularly to a balanced pumping L-band optical fiber amplifier comprising a first erbium-doped optical fiber, a second erbium-doped optical fiber, an absorbing erbium-doped optical fiber and at least two pumping lasers, the first erbium-doped optical fiber, the second erbium-doped optical fiber and the absorbing erbium-doped optical fiber being sequentially arranged in this order, and the at least two pumping lasers providing pumping light; wherein the first erbium-doped optical fiber and the second erbium-doped optical fiber both are injected with forward pumping light and backward pumping light, and the absorbing erbium-doped fiber is arranged downstream of the second erbium-doped optical fiber to absorb amplified spontaneous emission (ASE) generated in the amplifier. In the present invention, bidirectional pumping is applied in the first and last erbium-doped fibers in the optical path, and an erbium-doped optical fiber that has no pumping injection is added to absorb the ASE. Thus, the pumping conversion efficiency is greatly improved, the nonlinear four-wave mixing effect is reduced, and the problem that the L-band optical fiber amplifier has a high noise when utilizing the backward pumping is solved. Meanwhile, the noise figure and the manufacturing cost of the amplifier are reduced.

A converter includes a combiner configured to polarization-combine a first pump light and a second pump light, a nonlinear medium configured to wavelength-convert first signal light into second signal light to output the second signal light after wavelength conversion from a second port, and to wavelength-convert the second signal light into first signal light to output the first signal light after wavelength conversion from the first port, a first circulator configured to input the first signal light from the first port into the nonlinear medium, and output the first signal light after wavelength conversion in the nonlinear medium from the first port, and a second circulator configured to input the second signal light from the second port into the nonlinear medium, and output the second signal light after wavelength conversion in the nonlinear medium from the second port.

The optical relay is a C+L-band relay which is inserted between a first transmission path fiber and a second transmission path fiber, and comprises: a first optical fiber amplification unit which is inserted in a first line and amplifies one of a C-band signal or an L-band signal; a second optical fiber amplification unit which is inserted in a second line and amplifies one of the C-band signal or the L-band signal; and an inserting means which inserts some or all of the wavelengths of light output from the first optical fiber amplification unit into the second optical fiber amplification unit, or which inserts some or all of the wavelengths of light output from the second optical fiber amplification unit into the first optical fiber amplification unit.

A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.

A pulsed laser device includes: a semiconductor laser device that outputs laser light having a single wavelength; a semiconductor optical amplifier that receives the laser light output from the semiconductor laser device and amplifies the laser light to output; and a semiconductor-optical-amplifier driver that supplies a pulse-modulated semiconductor-optical-amplifier driving current to the semiconductor optical amplifier.

The disclosed subject matter relates to a polarization-maintaining very large mode area (PM VLMA) Erbium-doped fiber and a polarization maintaining, Er-doped VLMA amplifier.

Techniques for improving gain equalization in C- and L-band (C+L) erbium-doped fiber amplifier (EDFAs) are provided. For example, the C- and L-band amplification sections of a C+L EDFA may be separated and configured in a parallel arrangement or a serial arrangement. For both the parallel and serial arrangements, the C- and L-band amplification sections may share a common gain flattening filter (GFF) or each amplification section may include and employ a separate GFF. Moreover, in some examples, an interstage L-band GFF may be located before or upstream of the L-band amplification section such that the L-band optical signal is gain-equalized or flattened prior to the L-band amplification section amplifying the L-band.