CN100432820C - Filling type wavelength switching optical fiber laser - Google Patents

Abstract

The invention relates to a fiber laser for realizing wavelength switching of the fiber laser based on extracavity light injection. In the present invention, the optical fiber annular reflector is connected to the erbium-doped fiber amplifier, the erbium-doped fiber amplifier is connected to the fiber grating, the fiber grating is connected to the second port of the optical circulator, the first port of the optical circulator is connected to the tunable semiconductor laser, and the first port of the optical circulator is connected to the tunable semiconductor laser. Three ports are used as laser output ports. In the optical circulator, if the optical signal enters through the first port, it will be output through the second port, and if the optical signal enters through the second port, it will be output through the third port. The invention adopts laser injection to realize wavelength switching, which is convenient to control, and the switching wavelength can be flexibly selected.

Description

Injection Wavelength Switched Fiber Lasers

technical field

The invention belongs to the field of fiber lasers, and in particular relates to a fiber laser for realizing wavelength switching of the fiber laser based on extracavity light injection.

Background technique

With the development of optical communication technology and optical fiber sensing technology, fiber laser has increasingly become a focus of attention. Fiber lasers have the advantages of compact structure, high efficiency, low threshold, narrow linewidth, tunability, and fiber compatibility. They have important applications in optical communication systems, sensing systems, industrial processing, and monitoring. Recently, wavelength switching in fiber lasers has attracted great attention due to its great application value in optical communication systems and fiber optic sensing.

With the increasingly complex structure of optical communication systems, wavelength-switchable light sources have been paid attention to because of their important roles in wavelength routing and channel switching. The wavelength switching of fiber lasers has been experimentally reported. At present, the relatively mature technology adopts the design of overlapping resonators, and artificially controls the devices in the resonators (such as optical attenuators, polarization controllers, etc.) to introduce losses of different wavelength laser resonators to control the output wavelength of the laser. The output wavelength of the wavelength-switching fiber laser based on this technology is determined by the structure of the laser, which is not easy to change, and requires manual mechanical operation to achieve wavelength switching, which is very slow.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention proposes a fiber laser for realizing wavelength switching of the fiber laser based on extracavity light injection.

The invention includes a fiber ring reflection mirror, an erbium-doped fiber amplifier, a fiber grating, an optical circulator and a tunable semiconductor laser connected in series through an optical fiber. Specifically, the fiber loop reflector is connected to the erbium-doped fiber amplifier, the erbium-doped fiber amplifier is connected to the fiber grating, the fiber grating is connected to the second port of the optical circulator, the first port of the optical circulator is connected to the tunable semiconductor laser, and the optical circulator The third port serves as the output port of the laser. In the optical circulator, if the optical signal enters through the first port, it will be output through the second port; if the optical signal enters through the second port, it will be output through the third port.

In the present invention, the fiber ring mirror and the fiber grating constitute the laser resonant cavity, and the erbium-doped fiber amplifier becomes the gain medium of the laser. In the case of no extra-cavity laser injection, the output wavelength of the laser is determined by the reflection wavelength of the fiber grating. The above-mentioned whole system constitutes an injection-type wavelength-switched fiber laser. Turn on the erbium-doped fiber amplifier to obtain a single-wavelength laser output. Since the erbium-doped fiber amplifier can be regarded as a uniformly broadened gain medium, when the tunable semiconductor laser is injected into the fiber laser resonator composed of a fiber ring mirror and a fiber grating, the injection laser competes with the original fiber laser. If the injected laser is strong enough, it will win the competition, while the original fiber laser oscillating laser is suppressed, and the entire system outputs the injected wavelength laser. The injected laser light is amplified by passing through the erbium-doped fiber amplifier twice through the fiber ring mirror.

In the present invention, the wavelength of the tunable semiconductor laser is adjusted to the position where the wavelength needs to be switched, the output power is set, the tunable semiconductor laser is turned on, and the output wavelength of the laser can be converted to the switching wavelength, thereby realizing wavelength switching without manual mechanical operation. The invention is mainly applicable to optical communication and optical sensing. The invention adopts laser injection to realize wavelength switching, which is convenient to control, and the switching wavelength can be flexibly selected. In addition, the optical fiber of the invention is compatible, has a compact structure and is easy to integrate.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is a diagram of the wavelength switching effect of the fiber laser of the present invention.

Detailed ways

As shown in Figure 1, the output end of the fiber loop reflector 1 is optically connected to one end of the erbium-doped fiber amplifier 2, the other end of the erbium-doped fiber amplifier 2 is optically connected to one end of the fiber grating 3, and the other end of the fiber grating 3 is connected to the optical fiber The second port of the circulator 4 is optically connected, the first port of the fiber circulator 4 is optically connected to the output end of the tunable semiconductor laser 5, and the third port of the fiber circulator 4 is used as an output port of the fiber laser.

The gain bandwidth of the erbium-doped fiber amplifier 2 is 1525-1580 nanometers, the reflection wavelength of the fiber grating 3 is 1550.25 nanometers, and the tuning range of the tunable semiconductor laser 5 is 1500-1590 nanometers. Firstly, the erbium-doped fiber amplifier 2 is turned on, and the output wavelength of the fiber laser is 1550.25 nanometers as shown by the solid line in FIG. 2 . Then adjust the output wavelength of the tunable semiconductor laser 5 to 1555 nanometers, set the output optical power to 3 milliwatts, turn on the tunable semiconductor laser 5, and the output wavelength of the fiber laser is 1555 nanometers as shown by the dotted line in FIG. 2 . Thus, the wavelength switching of the fiber laser is realized.

Claims (1)

1. Injection-type wavelength-switching fiber laser, characterized in that the fiber laser includes a fiber optic ring mirror connected in series through an optical fiber, an erbium-doped fiber amplifier, a fiber grating, an optical circulator, and a tunable semiconductor laser; the fiber ring mirror is connected to an erbium-doped fiber Amplifier, the erbium-doped fiber amplifier is connected to the fiber grating, the fiber grating is connected to the second port of the optical circulator, the first port of the optical circulator is connected to the tunable semiconductor laser, and the third port of the optical circulator is used as the output port of the fiber laser; In the optical circulator, if the optical signal enters through the first port, it will be output through the second port, and if the optical signal enters through the second port, it will be output through the third port.

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