阅读说明：本技术 一种光纤波长计 (Optical fiber wavelength meter ) 是由 李晓炜 周芝福 胥晓春 杨义成 周柯江 于 2021-09-27 设计创作，主要内容包括：本发明公开了一种光纤波长计,包括单模耦合器和保偏耦合器,输入耦合器有一根输入光纤和二根输出光纤,输入光纤通过光纤连接器与待测光源的尾纤相连,一根输出光纤与保偏耦合器输入端相连,另一根输出光纤与第一光电探测器相连；保偏耦合器有二根输入保偏光纤和二根输出保偏光纤,二根输入保偏光纤分别与单模耦合器的一根输出光纤和第二光电探测器相连,二根输出保偏光纤不等长,根据设计选定长度差,将二根输出保偏光纤的尾端以主轴差90度熔接；另设置温度传感器靠近二根输入保偏光纤。将第一光电探测器、第二探测器和温度传感器的输出分别与信号处理单元相连,信号处理单元作信号的归一化处理、做非线性修正和温度修正,输出待测量的光波长。(The invention discloses an optical fiber wavelength meter, which comprises a single-mode coupler and a polarization maintaining coupler, wherein the input coupler is provided with an input optical fiber and two output optical fibers, the input optical fiber is connected with a tail fiber of a light source to be measured through an optical fiber connector, one output optical fiber is connected with the input end of the polarization maintaining coupler, and the other output optical fiber is connected with a first photoelectric detector; the polarization-maintaining coupler is provided with two input polarization-maintaining optical fibers and two output polarization-maintaining optical fibers, the two input polarization-maintaining optical fibers are respectively connected with one output optical fiber of the single-mode coupler and the second photoelectric detector, the two output polarization-maintaining optical fibers are unequal in length, and the tail ends of the two output polarization-maintaining optical fibers are welded together by 90 degrees of main shaft difference according to the length difference selected by design; and a temperature sensor is arranged close to the two input polarization maintaining optical fibers. The outputs of the first photoelectric detector, the second detector and the temperature sensor are respectively connected with a signal processing unit, and the signal processing unit performs signal normalization processing, nonlinear correction and temperature correction to output the wavelength of the light to be measured.)

1. The optical fiber wavelength meter is characterized by comprising a single-mode coupler and a polarization maintaining coupler, wherein the single-mode coupler is provided with an input optical fiber and two output optical fibers, and the tail end of one input optical fiber is connected with an optical fiber connector and can be connected with the tail end of a single-mode optical fiber of a light source with the wavelength to be measured; one of the two output optical fibers is connected to one input end of the polarization-maintaining coupler, and the other output optical fiber is connected to the first photoelectric detector;

one input optical fiber of the polarization maintaining coupler receives the output light of the single mode coupler, and the other input optical fiber is connected to the second photoelectric detector; the polarization-maintaining coupler is provided with two output polarization-maintaining optical fibers with different lengths, and the tail ends of the two output polarization-maintaining optical fibers are welded together by a polarization-maintaining optical fiber welding machine according to the angle of 90 degrees of a main shaft; arranging a temperature sensor near two output polarization maintaining optical fibers of the polarization maintaining coupler;

the output signals of the first photoelectric detector, the second photoelectric detector and the temperature sensor are respectively connected with a signal processing unit, and the signal processing unit comprises current-voltage conversion, amplification, analog-digital conversion, an embedded single chip microcomputer, a display and an upper computer communication interface.

2. The fiber optic wavemeter of claim 1 wherein the single mode coupler is a 1 x 2 single mode coupler and the polarization maintaining coupler is a 2 x 2 polarization maintaining coupler and has two unequal length output polarization maintaining fibers and is fused at a major axis 90 degree angle.

3. The fiber optic wavemeter of claim 2, wherein the single-mode coupler is a 2 x 2 single-mode coupler, the polarization maintaining coupler is a 1 x 2 polarization maintaining coupler, an optical fiber connector is arranged at the tail end of one input fiber of the single-mode coupler, the tail end of the single-mode fiber of the light source with the wavelength to be measured can be connected, and the other input fiber is connected with the second photodetector; one of the two output optical fibers is connected to the input optical fiber of the polarization-maintaining coupler, and the other output optical fiber is connected to the first photoelectric detector;

the polarization-maintaining coupler is provided with two output polarization-maintaining optical fibers with different lengths, and the tail ends of the two output polarization-maintaining optical fibers are welded together by a polarization-maintaining optical fiber welding machine according to a main shaft 90-degree angle; arranging a temperature sensor near two output polarization maintaining optical fibers of the polarization maintaining coupler; and output signals of the first photoelectric detector, the second photoelectric detector and the temperature sensor are respectively connected with the signal processing electric unit.

4. The fiber optic wavelength meter of claim 2, wherein the single-mode coupler is replaced by a three-port fiber optic circulator, a fiber connector is connected to the tail end of the input fiber of the first port of the fiber optic circulator, the tail end of the single-mode fiber of the wavelength source to be measured can be connected to the tail end of the input fiber of the fiber optic circulator, the output fiber of the second port of the fiber optic circulator is connected to an input fiber of the polarization maintaining fiber optic coupler, and the output fiber of the third port of the fiber optic circulator is connected to the first photodetector; the other input optical fiber of the polarization maintaining optical fiber coupler is connected with a second photoelectric detector;

the polarization-maintaining coupler is provided with two output polarization-maintaining optical fibers with different lengths, and the tail ends of the two output polarization-maintaining optical fibers are welded together by a polarization-maintaining optical fiber welding machine according to a main shaft 90-degree angle; arranging a temperature sensor near two output polarization maintaining optical fibers of the polarization maintaining coupler; and output signals of the first photoelectric detector, the second photoelectric detector and the temperature sensor are respectively connected with the signal processing electric unit.

Technical Field

The invention relates to a wavelength meter, in particular to an all-fiber wavelength meter insensitive to polarization.

Background

The principle of the traditional wavelength meter is based on a grating wavelength division method, an interference method formed by bulk optical elements or a wavelength division method formed by wavelength division devices, the traditional wavelength meter is not an all-fiber wavelength meter, the measurement result is often related to the polarization state of input light to be measured, and the traditional wavelength meter is expensive and large in size and is not beneficial to field operation of optical fiber engineering.

Disclosure of Invention

The invention aims to solve the problems that the wavemeter in the prior art is large in size, high in price, complex in manufacturing process and relevant to the measurement result and the polarization state of the optical wave to be measured, and provides the low-cost wavemeter with the all-fiber structure, which is not influenced by the polarization state of the input light to be measured.

In order to solve the technical problems, the invention adopts the technical scheme that:

an optical fiber wavelength meter comprises a single-mode coupler and a polarization maintaining coupler, wherein the single-mode coupler is provided with an input optical fiber with a connector and two output optical fibers, the two output optical fibers are respectively connected with the input optical fiber and a first photoelectric detector of the polarization maintaining coupler, the polarization maintaining coupler is provided with two input optical fibers and two output optical fibers, the other input optical fiber of the polarization maintaining coupler is connected with a second photoelectric detector, the two output optical fibers of the polarization maintaining coupler are not equal in length, the difference value is determined by the measured wavelength range, and the tail ends of the two output optical fibers are welded together according to a main shaft 90-degree angle;

the optical fiber wavelength meter also comprises a temperature sensor, an output optical fiber close to the polarization maintaining coupler, and a signal processing unit; the signal processing unit is used for carrying out signal normalization processing, nonlinear correction and temperature correction on input signals of the first photoelectric detector, the second photoelectric detector and the temperature sensor, displaying the input signals on a screen and transmitting the input signals to an upper computer.

Further, the single-mode coupler has two input optical fibers and two output optical fibers. The two output optical fibers are respectively connected with the input optical fiber of the polarization-maintaining coupler and the first photoelectric detector, the measurement polarization-maintaining coupler is provided with one input optical fiber and two output optical fibers, the two output optical fibers of the polarization-maintaining coupler are unequal in length, the difference value is determined by the measured wavelength range, and the tail ends of the two output optical fibers are welded together according to the angle of 90 degrees of a main shaft;

the optical fiber wavelength meter also comprises a temperature sensor, an output optical fiber close to the polarization maintaining coupler, and a signal processing unit; the signal processing unit is used for carrying out signal normalization processing, nonlinear correction and temperature correction on input signals of the first photoelectric detector, the second photoelectric detector and the temperature sensor, can be displayed on a screen and can transmit signals to an upper computer.

Further, the single-mode coupler is replaced by a three-port circulator, the circulator is provided with a first optical fiber port with a connector, a second optical fiber port of the circulator is connected with an input optical fiber of a polarization maintaining coupler, a third optical fiber port of the circulator is connected with a first photoelectric detector, the polarization maintaining coupler is provided with two input optical fibers and two output optical fibers, the other input optical fiber is connected with a second photoelectric detector, the two output optical fibers of the polarization maintaining coupler are not equal in length, the difference value is determined by the measured wavelength range, and the tail ends of the two output optical fibers are welded together according to a main shaft 90-degree angle;

the optical fiber wavelength meter also comprises a temperature sensor, an output optical fiber close to the polarization maintaining coupler, and a signal processing unit; the signal processing unit is used for carrying out signal normalization processing, temperature correction and nonlinear correction on input signals of the first photoelectric detector, the second photoelectric detector and the temperature sensor, displaying the input signals on a screen and transmitting the input signals to an upper computer.

The invention has the following beneficial effects:

the optical fiber wavelength meter provided by the invention is an all-fiber device structure, has the characteristics of small volume, low cost, easy manufacture and portability, and the output value of a measuring interference ring formed by the polarization-maintaining coupler has no relation with the polarization state of light to be measured, so that the wavelength meter is independent of polarization.

Drawings

Fig. 1 is a schematic diagram of a structure of an optical fiber wavelength meter composed of a 1 x 2 single-mode coupler and a 2 x 2 polarization-maintaining coupler;

fig. 2 is a schematic diagram of a structure of an optical fiber wavelength meter composed of a 2 x 2 single-mode coupler and a 1 x 2 polarization-maintaining coupler;

FIG. 3 is a schematic diagram of a fiber wavelength meter comprising a three-terminal circulator and a 2 x 2 polarization maintaining coupler;

reference numerals: single-mode coupler: 1; an input optical fiber connector: 1-1; a first photodetector: 2; a polarization maintaining coupler: 3; and (3) outputting a 90-degree welding point of the optical fiber main shaft by the polarization maintaining coupler II: 3-1; a second photodetector: 4; a temperature sensor: 5; a signal processing unit: 6; three-port circulator: 7; circulator first port fiber connector: 7-1.

Detailed Description

The technical solution of the present invention will be further clearly explained with reference to the drawings and the embodiments.

Example 1

Fig. 1 is a fiber wavemeter structure consisting of a 1 x 2 single mode coupler 1 and a 2 x 2 polarization maintaining coupler 3. Specifically, the 1 × 2 single-mode coupler 1 and the 2 × 2 polarization maintaining coupler 3 are respectively manufactured by using a single-mode fiber and a refractive index matching type polarization maintaining fiber through a tapering process.

An optical fiber connector 1-1 is manufactured on an input optical fiber of the 1 x 2 single-mode coupler 1 so as to be conveniently connected with an input optical fiber of a light source to be tested. Two output fibers of the 1 x 2 single-mode coupler 1 are respectively connected with one input fiber of the 2 x 2 polarization-maintaining coupler 3 and the first photoelectric detector 2. 2 x 2 another input optical fiber of the polarization-maintaining coupler 3 is connected with a second photoelectric detector 4

2 x 2 two output optical fibers of the polarization maintaining coupler 3 are unequal in length, the length difference of the two output optical fibers is determined according to the required measuring wavelength range, then the tail ends of the two output optical fibers are welded together by a polarization maintaining optical fiber welding machine according to the angle of 90 degrees of a main shaft, and a welding point is 3-1. The temperature sensors 5 are arranged in the vicinity of the two output fibres close to the 2 x 2 polarization maintaining fibre coupler 3.

The output signals of the first photoelectric detector 2, the second photoelectric detector 4 and the temperature sensor 5 are input to the signal processing unit 6 for normalization processing, nonlinear correction and temperature correction, the wavelength value is displayed on a screen, and the wavelength value can be transmitted to an upper computer.

Example 2

Fig. 2 is a fiber wavemeter structure consisting of a 2 x 2 single mode coupler 1 and a 1 x 2 polarization maintaining coupler 3. Specifically, the 2 × 2 single-mode coupler 1 and the 1 × 2 polarization maintaining coupler 3 are respectively manufactured by using a single-mode fiber and a refractive index matching type polarization maintaining fiber through a tapering process.

And 2, an input optical fiber of the single-mode coupler 1 is provided with an optical fiber connector 1-1 so as to be conveniently connected with the input optical fiber of the light source to be tested. The other input optical fiber is connected to the second photodetector 4; two output fibers of the 2 x 2 single-mode fiber coupler 1 are respectively connected with an input fiber of the 1 x 2 polarization-maintaining coupler 3 and the first photoelectric detector 2.

1 x 2 polarization maintaining fiber coupler 3 two output fibers are unequal in length, the length difference is determined according to the required measuring wavelength range, then the tail ends of the two output fibers are welded together by a polarization maintaining fiber welding machine according to the angle of 90 degrees of a main shaft, and the welding point is 3-1. The temperature sensors 5 are arranged in the vicinity of the two output fibres close to the 2 x 2 polarization maintaining coupler 3.

The output signals of the first photoelectric detector 2, the second photoelectric detector 4 and the temperature sensor 5 are input to the signal processing unit 6 for normalization processing, nonlinear correction and temperature correction, the wavelength value is displayed on a screen, and the wavelength value can be transmitted to an upper computer.

Example 3

Fig. 3 is a fiber wavemeter structure consisting of a three-port circulator 7 and a 2 x 2 polarization maintaining fiber coupler 3. 2, the 2 x 2 polarization maintaining fiber coupler 3 is made of refractive index matching type polarization maintaining fiber by a tapering process.

An optical fiber connector 7-1 is manufactured on the first port input optical fiber of the three-port circulator 7 so as to be conveniently connected with the input optical fiber of the light source to be tested. And a second port output optical fiber of the circulator 7 is connected with one input optical fiber of the 2 x 2 polarization-maintaining coupler 3, and a third port output optical fiber of the circulator 7 is connected with the first photoelectric detector. The other input fiber of 2 x 2 polarization maintaining coupler 3 is connected to the second photodetector 4.

2 x 2 two output optical fibers of the polarization maintaining coupler 3 are unequal in length, the length difference of the two output optical fibers is determined according to the required measuring wavelength range, then the tail ends of the two output optical fibers are welded together by a polarization maintaining optical fiber welding machine according to the angle of 90 degrees of a main shaft, and a welding point is 3-1. The temperature sensors 5 are arranged in the vicinity of the two output fibres close to the 2 x 2 polarization maintaining fibre coupler 3.

The output signals of the first photoelectric detector 2, the second photoelectric detector 4 and the temperature sensor 5 are input to the signal processing unit 6 for normalization processing, nonlinear correction and temperature correction, the wavelength value is displayed on a screen, and the wavelength value can be transmitted to an upper computer.

Specifically, taking the scheme of embodiment 1 as an example, the wavelength value of the light to be measured is in 1520nm-1590 wave band, and the 1 × 2 single-mode coupler 1 is insensitive to the tapered wavelength by 50%: the 50% directional coupler, 2 x 2 polarization maintaining coupler 3 refractive index matching type polarization maintaining fiber are manufactured by a tapering process, and the light splitting ratio is 50%: 50 percent, the length difference of the two output optical fibers is 5 cm, and the two tail ends are welded by a polarization maintaining welding machine according to the main shaft difference of 90 degrees. The first photoelectric detector and the second photoelectric detector adopt PIN-FETs, the temperature sensor adopts a semiconductor sensor with digital output, the signal processing unit comprises current-voltage conversion, amplification filtering, AD conversion, an embedded single chip microcomputer, a display screen and an upper computer interface, and the measurement accuracy of the wavelength meter reaches 0.05 nm.

The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical scheme obtained by adopting the mode of equivalent replacement or equivalent transformation is within the protection scope of the invention.