阅读说明：本技术 可调谐光滤波器 (Tunable optical filter ) 是由 湛欢 李震 汪树兵 钟辉 王亦军 温冰 汤磊 于 2019-11-11 设计创作，主要内容包括：可调谐光滤波器,涉及光滤波器技术领域,其包括第一偏振控制器、第二偏振控制器、转换光纤、起偏器,所述转换光纤为保偏光纤,第一偏振控制器的输入端为本可调谐光滤波器的输入端,第一偏振控制器的输出端连接所述转换光纤的一端,所述转换光纤的另一端连接第二偏振控制器的输入端,第二偏振控制器的输出端连接所述起偏器的输入端,所述起偏器的输出端为本可调谐光滤波器的输出端。利用保偏光纤的特性,结合第一偏振控制器和所述转换光纤,将选择光的波长转换为选择光的偏振态,通过选择最后输出的光的偏振态即可实现对输出的光的波长的选择,也就实现了不同波长的滤波,因此可实现较大工作波长范围的调节。(A tunable optical filter relates to the technical field of optical filters, and comprises a th polarization controller, a second polarization controller, a conversion optical fiber and a polarizer, wherein the conversion optical fiber is a polarization-maintaining optical fiber, the input end of the th polarization controller is the input end of the tunable optical filter, the output end of the th polarization controller is connected with the end of the conversion optical fiber, the other end of the conversion optical fiber is connected with the input end of the second polarization controller, the output end of the second polarization controller is connected with the input end of the polarizer, and the output end of the polarizer is the output end of the tunable optical filter.)

1. The tunable optical filter is characterized by comprising an th polarization controller, a second polarization controller, a conversion optical fiber and a polarizer, wherein the conversion optical fiber is a polarization maintaining optical fiber, the input end of the th polarization controller is the input end of the tunable optical filter, the output end of the th polarization controller is connected with the end of the conversion optical fiber, the other end of the conversion optical fiber is connected with the input end of the second polarization controller, the output end of the second polarization controller is connected with the input end of the polarizer, and the output end of the polarizer is the output end of the tunable optical filter.

2. The tunable optical filter of claim 1, wherein the length of the conversion fiber ranges from 50cm to 1000 cm.

3. The tunable optical filter of claim 2, wherein the length of the conversion fiber is 200cm or 400 cm.

4. The tunable optical filter of claim 1, wherein the th polarization controller and the second polarization controller are fiber-extruded polarization controllers.

5. The tunable optical filter of claim 1, wherein the polarizer is a fiber-type polarizer.

6. The tunable optical filter of claim 1, wherein the input and output fibers of both the th and second polarization controllers are single mode fibers.

7. The tunable optical filter of claim 1, wherein the input and output fibers of the polarizer are polarization maintaining fibers.

Technical Field

The invention relates to the technical field of optical filters.

Background

The common optical filters include FBG filters, F-P cavity optical filters, multilayer film filters, etc. these filters use the coherence of light and match with certain optical wavelengths by constructing proper structural dimensions, thus realizing the selection of wavelengths.

Disclosure of Invention

In view of the above, the present invention provides tunable optical filters, which have a large tunable range of operating wavelengths.

In order to achieve the above object, the following technical solutions are proposed.

The tunable optical filter comprises an th polarization controller, a second polarization controller, a conversion optical fiber and a polarizer, wherein the conversion optical fiber is a polarization maintaining optical fiber, the input end of the th polarization controller is the input end of the tunable optical filter, the output end of the th polarization controller is connected with the end of the conversion optical fiber, the other end of the conversion optical fiber is connected with the input end of the second polarization controller, the output end of the second polarization controller is connected with the input end of the polarizer, and the output end of the polarizer is the output end of the tunable optical filter.

The wavelength of the selected light is converted into the polarization state of the selected light by combining the polarization controller and the conversion optical fiber by utilizing the characteristics of the polarization maintaining optical fiber, the wavelength of the selected light is converted into the polarization state of the selected light by selecting the polarization state of the light which is finally output, and the selection of the wavelength of the output light can be realized, so that the filtering of different wavelengths is realized.

Wherein the length of the conversion fiber is in a range of 50cm or more and 1000cm or less.

Wherein the length of the conversion optical fiber is 200cm or 400 cm.

The th polarization controller and the second polarization controller are both optical fiber extrusion type polarization controllers.

Wherein the polarizer is an optical fiber polarizer.

The input optical fiber and the output optical fiber of the th polarization controller and the second polarization controller are single-mode optical fibers.

And the input optical fiber and the output optical fiber of the polarizer are polarization maintaining optical fibers.

Drawings

FIG. 1 is a schematic diagram of a tunable optical filter according to the present invention;

FIG. 2 is a perspective schematic diagram of a tunable optical filter of the present invention;

FIG. 3 is a schematic diagram of the normalized filtering curves obtained for embodiments of the tunable optical filter of the present invention in a certain state;

fig. 4 is a schematic diagram of a normalized filtering curve obtained for another embodiments of the tunable optical filter of the present invention in a certain state.

The reference numerals include:

th polarization controller 1, input fiber 11, output fiber 12;

a second polarization controller 2, an input fiber 21, an output fiber 22;

a conversion optical fiber 3;

polarizer 4, input fiber 41, output fiber 42.

Detailed Description

The invention is described in detail below with reference to specific embodiments.

As shown in fig. 1, the tunable optical filter of the present embodiment includes -th polarization controller 1, 2-second polarization controller 2, 3-conversion optical fiber, 4-polarizer, 3-conversion optical fiber is polarization maintaining optical fiber, optionally PM980 optical fiber, -th polarization controller 1 has an input end a of the tunable optical filter, -th polarization controller 1 has an output end connected to end of 3-conversion optical fiber, 3-conversion optical fiber has another end connected to input end of 2-second polarization controller, 2-second polarization controller 2 has an output end connected to input end of 4-polarizer, 4 has an output end b of the tunable optical filter, since 3-conversion optical fiber is polarization maintaining optical fiber, which has larger polarization mode dispersion, the delay difference between light transmitted through fast axis of polarization maintaining optical fiber and light passing through slow axis of polarization maintaining optical fiber is related to wavelength, that the polarization state of light output from polarization maintaining optical fiber is related to wavelength, using the above characteristics of polarization maintaining optical fiber, combining 1-polarization controller 1 and conversion optical fiber 3, converting the wavelength of selected light into wavelength of tunable optical fiber, adjusting light, converting the wavelength of tunable optical fiber into wavelength of tunable optical fiber, and wavelength adjusting light, which can be adjusted by polarization controller 358-polarization controller, thus realizing the wavelength adjusting optical wavelength adjusting by the tunable optical filter, which can be adjusted by the tunable optical fiber, and the wavelength adjusting optical fiber, which can be adjusted by the tunable optical fiber, and the tunable optical fiber, which can be adjusted by polarization controller, and the polarization controller 2, and the tunable optical fiber, thus realizing the wavelength adjusting optical filter, the tunable optical filter can realize the wavelength adjusting optical filter, the wavelength adjusting filter of the tunable optical filter, which can realize the wavelength adjusting optical filter of the tunable optical fiber, the tunable optical filter of the tunable optical filter, which can realize the invention, the invention can realize the invention, the invention can realize the invention, the invention can realize the invention.

In the present embodiment, the length of the conversion fiber 3 is in the range of 50cm inclusive to 1000cm inclusive, preferably 200cm or 400 cm.

The th polarization controller 1 and the second polarization controller 2 are fiber-extruded polarization controllers, and can be selected from manual polarization controllers or electric polarization controllers, and the polarizer 4 is preferably a fiber-type polarizer 4.

As shown in fig. 2, preferably, the input fiber 11 and the output fiber 12 of the th polarization controller 1, and the input fiber 21 and the output fiber 22 of the second polarization controller 2 are both single-mode fibers, and the input fiber 41 and the output fiber 42 of the polarizer 4 are both polarization-maintaining fibers.

Fig. 3 shows a normalized filter curve obtained at a certain state for a 200cm transition fiber 3 of the tunable optical filter of the present invention, with the wavelength on the abscissa, in nm, and the transmittance normalized to on the ordinate.

Fig. 4 shows a normalized filter curve obtained at a certain state for a 400cm transition fiber 3 of the tunable optical filter of the present invention, with wavelength on the abscissa and transmission in nm on the ordinate of .

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.