CN201750040U - Multiwavelength Fiber Laser Based on Chirped Grating - Google Patents

Abstract

The utility model discloses a chirp grating based multi-wavelength fiber laser which comprises a pumping source and a ring resonator, wherein the ring resonator at least includes a wavelength division multiplexer, an optoisolator, a coupler, a polarization controller, a modulator, a gain fiber, and a chirp grating for increasing chromatic dispersion in the ring resonator; the wavelength division multiplexer is connected with an input end of the optoisolator through an optical fiber; an output end of the optoisolator is connected with the coupler through the optical fiber; the coupler is connected with the polarization controller through the optical fiber; the polarization controller is connected with the modulator through the optical fiber; the modulator is connected with the chirp grating through the optical fiber; and the chirp grating are connected with the wavelength division multiplexer through the gain fiber. Therefore, compared with conventional multi-wavelength lasers, the chirp grating based multi-wavelength fiber laser has lowered cost and reduced volume and weight and improves the reliability.

Description

Multiwavelength Fiber Laser Based on Chirped Grating

technical field

The utility model relates to the field of laser technology, in particular to a multi-wavelength fiber laser based on a chirped grating.

Background technique

With its superior performance and value-for-money price, fiber lasers are widely used in optical communication, sensing, printing, marking, material processing, medical treatment and other fields, and may replace traditional lasers to a large extent, and open up some new Laser application field, expand the scale of laser industry. Among them, multi-wavelength fiber laser is a new type of light source with great development prospects in the fields of wavelength division multiplexing communication systems and sensing. There are many technologies for realizing multi-wavelength fiber lasers, such as the active mode-locked fiber laser shown in Figure 1, the ring resonator is composed of wavelength division multiplexer (WDM) 1, erbium-doped fiber (EDF) 2, dispersion compensation fiber (DCF) ) 3, modulator (modulator) 4, polarization controller (PC) 5, coupler (coupler) 6, optical isolator (OI) 7 and so on. Pumping (pump) light is effectively coupled into the erbium-doped fiber 2 through the wavelength division multiplexer 1, and the optical isolator 7 ensures the unidirectional transmission of the laser in the resonator so that better pumping conversion efficiency is arranged. And avoid the influence of the end face reflection of the output end on the resonant cavity. This technology uses the dispersion compensating fiber 3 to increase the intracavity dispersion, and at the same modulation frequency, different orders of harmonic mode locking can be realized, thereby realizing multi-wavelength laser output. However, the price of the DCF used in the fiber laser in this technology is relatively high, and the size of the required DCF is relatively long, which is inconvenient in application.

In summary, the multi-wavelength fiber lasers in the prior art obviously have inconveniences and defects in actual use, so it is necessary to improve them.

Utility model content

In view of the above defects, the purpose of this utility model is to provide a multi-wavelength fiber laser based on a chirped grating, which has the advantages of small size, light weight and low cost compared with the existing multi-wavelength fiber laser.

In order to achieve the above object, the utility model provides a multi-wavelength fiber laser based on a chirped grating, including a pump source and a ring resonator, and the ring resonator at least includes a wavelength division multiplexer, an optical isolator, a coupler, A polarization controller, a modulator, a gain fiber and a chirped grating for increasing the dispersion in the ring resonator, the wavelength division multiplexer is connected to the input end of the optical isolator through an optical fiber, and the optical isolator The output end of the optical fiber is connected to the coupler, the coupler is connected to the polarization controller through the optical fiber, the polarization controller is connected to the modulator through the optical fiber, and the modulator is connected to the chirp through the optical fiber. The chirped grating is connected to the wavelength division multiplexer through the gain fiber.

According to the chirped grating-based multi-wavelength fiber laser of the present invention, the gain fiber is an erbium-doped fiber.

According to the chirped grating-based multi-wavelength fiber laser of the present invention, the gain fiber is an Er-Yb co-doped fiber.

The utility model replaces the device of the ring resonant cavity of the multi-wavelength fiber laser, connects the chirped grating and the wavelength division multiplexer through the gain fiber, and connects the chirped grating and the modulator with an optical fiber, thereby replacing the dispersion compensation of the prior art Optical fiber, the use of chirped gratings can greatly reduce the volume and weight of multi-wavelength fiber lasers, improve reliability, and reduce costs.

Description of drawings

Fig. 1 is the structural diagram of the ring resonator of the multi-wavelength fiber laser of prior art;

Fig. 2 is a structural diagram of the chirped grating-based multi-wavelength fiber laser of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

FIG. 2 shows the basic structure of the present invention. A chirped grating-based multi-wavelength fiber laser 100 includes a pump source 10 and a ring resonant cavity 20 . Wherein, the ring resonator 20 at least includes a wavelength division multiplexer 21, an optical isolator 22, a coupler 23, a polarization controller 24, a modulator 25, a gain fiber 26 and a chirped grating 27, and the wavelength division multiplexer 21 passes through an optical fiber Connected to the input end of the optical isolator 22, the output end of the optical isolator 22 is connected to the coupler 23 through the optical fiber, the coupler 23 is connected to the polarization controller 24 through the optical fiber, and the polarization controller 24 is connected to the modulator 25 through the optical fiber The modulator 25 is connected to the chirped grating 27 through an optical fiber, and the chirped grating 27 is connected to the wavelength division multiplexer 21 through the gain fiber 26.

In combination with Fig. 1, the utility model uses a chirped grating 27 to replace the dispersion compensating fiber 3 in the prior art, so as to increase the intracavity dispersion. Under the same modulation frequency, different orders of harmonic mode locking can be realized, thereby realizing multiple wavelength laser output.

In the actual working process, the pump source 10 emits pump laser light (such as: pump light with a pump wavelength of 980nm) and transmits it to the wavelength division multiplexer 21, and the pump light is coupled by the wavelength division multiplexer 21 and then transmitted through the optical fiber As for the gain fiber 26, the gain fiber 26 may be an erbium-doped fiber or an Er-Yb co-doped fiber. In order to improve the absorption efficiency of the pump light and reduce its loss in the optical fiber, this kind of gain fiber 26 of suitable length can be adopted according to the parameters such as the intensity of the pump light and the absorption coefficient of the gain fiber 26, so that the pump Light can be completely absorbed.

The optical isolator 22 can ensure the unidirectional transmission of laser light in the ring resonant cavity 20 , so that the pumping light has better pump conversion efficiency, and avoids the impact of the end face reflection of the output end on the ring resonant cavity 20 . The modulator 25 is an electro-optic modulator, which can be a lithium niobate electro-optic modulator or other modulators. By adjusting the DC bias voltage of the modulator 25, it can work in the linear region. The RF driving frequency of the modulator 25 can be changed, and the output laser wavelength can be changed, so that multi-wavelength tunable laser output can be realized.

The working process of the present utility model is specifically described below in conjunction with the drawings.

The pump source 10 emits pump light with a wavelength of 980nm, and after passing through the wavelength division multiplexer 21 , the pump light is coupled to the gain fiber 26 . After being absorbed by the gain fiber 26, it is converted into laser light with a wavelength of about 1550nm. The converted laser transmits and oscillates clockwise in the ring resonator 20 . When the laser passes through the chirped grating 27, since the dispersion of the chirped grating 27 is different for different wavelengths, different orders of harmonic mode-locking can be realized under the same frequency modulation, thereby realizing multi-wavelength laser pulse output, and can be coupled from device 23 output.

In summary, the utility model replaces the ring resonator device of the multi-wavelength fiber laser, connects the chirped grating and the wavelength division multiplexer through the gain fiber, and connects the chirped grating and the modulator through the optical fiber, thereby replacing In the dispersion compensating optical fiber in the prior art, the use of a chirped grating can greatly reduce the volume and weight of a multi-wavelength fiber laser, improve reliability, and reduce cost.

Of course, the utility model can also have other various embodiments, and those skilled in the art can make various corresponding changes and deformations according to the utility model without departing from the spirit and essence of the utility model, but These corresponding changes and deformations should all belong to the protection scope of the appended claims of the present utility model.

Claims (3)

1. A multi-wavelength fiber laser based on a chirped grating, comprising a pump source and a ring resonator, characterized in that the ring resonator at least includes a wavelength division multiplexer, an optical isolator, a coupler, a polarization controller , a modulator, a gain fiber and a chirped grating for increasing the dispersion in the ring resonator, the wavelength division multiplexer is connected to the input end of the optical isolator through an optical fiber, and the output end of the optical isolator connected to the coupler via an optical fiber, the coupler is connected to the polarization controller via an optical fiber, the polarization controller is connected to the modulator via an optical fiber, and the modulator is connected to the chirped grating via an optical fiber , the chirped grating is connected to the wavelength division multiplexer through the gain fiber. 2. The chirped grating-based multi-wavelength fiber laser according to claim 1, wherein the gain fiber is an erbium-doped fiber. 3. The chirped grating-based multi-wavelength fiber laser according to claim 1, wherein the gain fiber is an Er-Yb co-doped fiber.

Images