A tunable multi-wavelength fiber laser based on wavelength-dependent polarization separation

Abstract

The invention discloses a tunable multi-wavelength optical fiber laser based on wavelength dependent polarization separation. The optical fiber laser comprises an optical amplifier, a polarizer, a plurality of optical fiber Bragg gratings, a plurality of polarization controllers and a coupler; the optical amplifier is used for outputting and amplifying laser; the polarizer is connected with the optical amplifier; the plurality of optical fiber Bragg gratings are sequentially arranged along a transmission path of a laser source and have different Bragg reflection wavelengths; one polarization controller is arranged before each of the optical fiber Bragg gratings to adjust the polarization state and the polarization dependent loss of the corresponding reflection polarization laser; the coupler is arranged on emergent light paths of the optical fiber Bragg gratings and is used for outputting the reflection polarization laser with multiple wavelengths. With the adoption of a wavelength dependent polarization separation technology, the polarization state of optical fiber Bragg grating reflecting light with different Bragg reflection wavelengths is arranged; the polarization state and the polarization dependent loss of the polarization laser are adjusted through the polarization controller, so that the tunable multi-wavelength polarized laser is realized.

Description

technical field [0001] The invention relates to the field of fiber lasers, in particular to a tunable multi-wavelength fiber laser based on wavelength-dependent polarization separation. Background technique [0002] With the development of optical fiber communication technology, the optical communication system has higher requirements on the transmission capacity, and the optical wavelength division multiplexing system has become an indispensable part of the communication system. There are two methods for the traditional multi-wavelength fiber laser to realize multi-wavelength laser, one One is based on using a separate gain medium for each wavelength; the other is to suppress the mode competition of the gain medium by designing a special structure. For the first type, the more output wavelengths, the more redundant the structure of the system. In a fixed system, the number of output multi-wavelength lights is fixed, and the number of output multi-wavelength lights cannot be...

AI Technical Summary

Problems solved by technology

For the first type, the more output wavelengths, the more redundant the structure of the system. In a fixed system, the number of output multi-wavelength lights is fixed, and the number of output multi-wavelength lights cannot be adjusted; the second type is due to erbium doping at room temperature The gain of the erbium fiber has the characteristic of uniform broadening, which will lead to mode competition in the laser, and the multi-wavelength laser output cannot be stably established.

[0003] Therefore, it is difficult to achieve stable multi-wavelength output by using the same erbium-doped fiber for gain of lasers of different wavelengths

In the traditional method, liquid nitrogen is used to cool the erbium-doped fiber to suppress competition, but it is not suitable for practical applications due to its harsh temperature requirements

There is also based on the nonlinear effect to suppress the mode competition in the laser cavity. This system increases the nonlinear effect through several kilometers of single-mode fiber or expensive high nonlinear fiber, resulting in a very complicated system structure, and at the same time it is impossible to adjust the output. number of wavelengths

[0004] In the prior art, multi-wavelength lasers based on the polarization hole-burning effect are realized by engraving fiber Bragg gratings in high-birefringence fibers. However, the number of output multi-wavelength lasers cannot be adjusted, and the output of multi-wavelength lasers cannot be controlled. stability

To sum up, in the prior art, no stable and tunable multi-wavelength laser output can be achieved in the scheme of multi-wavelength laser output

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