CN103682977A - Tunable Brillouin laser generation method based on dispersion flattened fiber and device thereof - Google Patents

Abstract

The present invention proposes a tunable Brillouin laser generation method and device based on a dispersion flat optical fiber. The same DFB pump laser source is used to generate a dual-wavelength Brillouin laser, which effectively suppresses the phase noise; for the first time, the symmetry, stability Stokes light and anti-Stokes light with better performance can form dual-wavelength laser, which can realize equal-amplitude output of dual wavelengths and improve wavelength stability; the dual-wavelength laser generation scheme of the present invention is novel, simple and feasible, and can be used as Further in-depth research in the fields of microwave photonics, optical fiber communication, and fiber optics has provided support.

Description

A Tunable Brillouin Laser Generation Method and Device Based on Dispersion Flat Fiber

Technical field

The invention relates to a tunable Brillouin laser generation method and device based on a dispersion flat optical fiber, which can be applied to the fields of microwave photonics, optical fiber communication, optical fiber optics and the like.

Background technique

In recent years, radio-over-fiber communication technology (Radio-over-fiber), which combines optical fiber communication technology and high-frequency wireless access, has become a research hotspot for ultra-broadband access as a newly developed communication technology. Stable single longitudinal mode dual-wavelength lasers have become one of the key technologies to realize wireless optical fiber communication, especially the two-wavelength interval and phase of the laser should have high stability. In response to the above-mentioned stringent requirements, the usual practice is to use complex subsystems such as high-stable microwave reference signal sources, optical injection locking technology or optical phase-locked ring technology. In recent years, Wu Zhijing and others from Shanghai Jiao Tong University have proposed a dual-wavelength Brillouin fiber laser, which uses optical resonators and cascaded resonators to generate single-mode lasers with different frequencies based on the Brillouin effect-Stowe While satisfying wavelength and phase stability, the X-ray method does not need to use complex subsystems such as high-stable microwave reference signal source, optical injection locking technology, or optical phase-locked ring technology [1. Wu Zhijing et al., based on dual-wavelength Bri Optically generated microwave device for deep fiber laser, invention patent application publication specification CN201010132938.0]. This also shows that the Brillouin laser method based on nonlinear effects has wavelength and phase stability, and is an effective and important method for generating high-performance dual-wavelength lasers in the field of microwave photonics. However, a drawback of the Brillouin laser described above is that there is a large difference in the magnitude of the two wavelengths.

Invention patent application content

Aiming at the above problems caused by dual-wavelength lasers, we have made a more detailed study on the Brillouin effect, and found that based on the Brillouin scattered light-Stokes light and Brillouin scattered light-anti-Stokes light generated by our laser system, The X-ray has very good symmetry and stability, and it has a larger difference with the literature [1], [2. Agrawal, nonlinear fiber optics, 4e, Elsevier (Singapore) Pte Ltd. 2009, 1-528]. The magnitude difference is different. In view of this, the present invention proposes a tunable Brillouin laser generation method and device based on a dispersion-flat optical fiber. The wavelength tunable Brillouin laser subsystem can solve the problems related to the wavelength stability, phase stability, and unequal amplitude of the two wavelengths in the dual-wavelength laser generation, and can avoid the use of highly stable microwave reference signal sources and optical injection. Complex subsystems such as locking technology or optical phase-locked ring technology.

The technical solution adopted by the present invention to solve its technical problems is:

The present invention proposes a tunable Brillouin laser generation method and device based on a dispersion-flat optical fiber. The technical solution to be adopted: Stokes light and anti-Stokes light with better symmetry and stability are used for the first time A dual-wavelength tunable Brillouin laser subsystem is produced. The Brillouin laser-Stokes light and Brillouin laser-anti-Stokes light generated by the single longitudinal mode tunable narrow-linewidth DFB pump light transmitted in the dispersion-flat fiber are output to the filter through the splitter (such as reflective fiber Bragg grating, etc.) to filter out the pump light to obtain symmetrical and stable Stokes light and anti-Stokes light, and form a dual-wavelength Brillouin laser. By tuning the wavelength and power of the DFB pump light, Stokes light and anti-Stokes light with different wavelengths and powers can be obtained, that is, dual-wavelength Brillouin lasers with different wavelengths and powers.

The beneficial effects of the present invention are:

The present invention proposes a tunable Brillouin laser generation method and device based on a dispersion-flat optical fiber; the same DFB pump laser light source is used to generate a dual-wavelength Brillouin laser, which effectively suppresses phase noise; the symmetry and stability are relatively high. Good Stokes light and anti-Stokes light form a dual-wavelength laser, which can realize dual-wavelength equal-amplitude output and improve wavelength stability; the dual-wavelength laser generation scheme of the present invention is novel, simple and feasible, and can effectively suppress phase noise , Dual-wavelength equal-amplitude output, high wavelength stability. The invention provides support for further in-depth research in the fields of microwave photonics, optical fiber communication, optical fiber optics and the like.

Description of drawings

The present invention proposes a tunable Brillouin laser generation method and device based on a dispersion-flat optical fiber. In FIG. 1, 1 is a single longitudinal mode tunable narrow-linewidth DFB pump laser, and 2 is a splitter 99:1. 3 is dispersion flat fiber, 4 is circulator, 5 is filter (such as reflective fiber grating, etc.), 6 is Brillouin laser output port or Brillouin laser amplification output port, 7 is partial pump light output, as shown in Fig. Middle 8 is the spectrum scanned by spectrometer AQ6319 at the junction of splitter 2 and circulator 4. The spectral line in the middle of the spectrum is pump light, the spectral line on the left side of the spectrum is Brillouin laser-anti-Stokes light, and the spectral line on the right side of the spectrum is Brillouin laser-Stokes light. The Brillouin laser output terminal can be connected to various measuring instruments (such as the electric spectrometer E4440A, the spectrometer AQ6319, etc.; used for the measurement and analysis of various parameters of the Brillouin laser output).

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and implementation.

Brillouin laser-Stokes light and distribution generated by single longitudinal mode tunable narrow linewidth DFB pump laser (1) transmitted through 99% port of splitter 99:1 (2) to dispersion flattened fiber (3) Liyuan laser-anti-Stokes light, Stokes light and anti-Stokes light are output to the 1% port of the splitter (2) to the 1 port of the circulator (4), and the output light of the 2 port of the circulator After the pump light is filtered out by the filter (5) (such as reflective fiber grating, etc.), Stokes light and anti-Stokes light with better symmetry and stability are obtained. The Stokes light forms a dual-wavelength Brillouin laser, which can be directly output at the output terminal (6) or output after optical amplification. By tuning the wavelength of the DFB pump light (1), different wavelengths of Stokes light and anti-Stokes light, that is, different wavelengths of dual-wavelength Brillouin lasers can be obtained. By tuning the power of the DFB pump light, Stokes light and anti-Stokes light with different powers can be obtained, that is, dual-wavelength Brillouin lasers with different powers. By changing the splitting ratio of the splitter (2), Stokes light and anti-Stokes light with different powers, ie, dual-wavelength Brillouin lasers with different powers, can be obtained. Part of the pump light is output from port 3 of the circulator to the output port (7). The Brillouin laser output terminal can be connected to various measuring instruments (such as the electric spectrometer E4440A, the spectrometer AQ6319, etc.; used for the measurement and analysis of various parameters of the Brillouin laser output). The dual-wavelength generation scheme of the invention is novel, simple and feasible, and provides support for further in-depth research in the fields of microwave photonics, optical fiber communication, optical fiber optics and the like.

Claims (3)

1. A tunable Brillouin laser generation method based on dispersion-flattened fiber: Brillouin laser-Stokes light and Brillouin generated by single longitudinal mode tunable narrow-linewidth DFB pump laser transmitted in dispersion-flattened fiber Laser-anti-Stokes light, which is output to the filter to filter the pump light through a splitter to obtain symmetrical and stable Stokes light and anti-Stokes light, by Stokes Light and anti-Stokes light form a dual-wavelength Brillouin laser. 2. according to the device of the described method of claim 1, it is characterized in that: single longitudinal mode tunable narrow-linewidth DFB pump laser light (1) is through the 99% port of splitter 99:1 (2) to dispersion-flat optical fiber ( 3) Brillouin laser-Stokes light and Brillouin laser-anti-Stokes light produced by transmission, Stokes light and anti-Stokes light pass through the 1% port of splitter (2) output to the 1 port of the circulator (4), and the output light of the 2 port of the circulator is filtered by the filter (5) (reflective fiber grating) to obtain Stokes light and reflective light with good symmetry and stability. The Stokes light is a dual-wavelength Brillouin laser formed by the Stokes light and the anti-Stokes light, and the laser can be directly output at the output terminal (6) or output after optical amplification. By tuning the wavelength of the DFB pump light, different wavelengths of Stokes light and anti-Stokes light can be obtained, that is, different dual-wavelength Brillouin lasers. Part of the pump light is output from port 3 of the circulator to the output port (7). The Brillouin laser output terminal can be connected to various measuring instruments (such as the electric spectrometer E4440A, the spectrometer AQ6319, etc.; used for the measurement and analysis of various parameters of the Brillouin laser output). 3. according to the described device of claim 2, it is characterized in that: adopt same DFB pumping laser (1) light source to produce dual-wavelength Brillouin laser, effectively restrain phase noise; Symmetry, stable Stokes The dual-wavelength laser is formed by the Stokes light and the anti-Stokes light, which can realize dual-wavelength equal-amplitude output and improve wavelength stability. By tuning the wavelength and power of the DFB pump light (1), dual-wavelength Brillouin lasers with different wavelengths and powers can be obtained; by changing the splitting ratio of the splitter (2), Stokes light and reflective lasers with different powers can be obtained. Stokes light is a dual-wavelength Brillouin laser with different powers.

Images