CN218469892U

CN218469892U - Optical fiber demodulator calibration equipment

Info

Publication number: CN218469892U
Application number: CN202221864618.9U
Authority: CN
Inventors: 周振宇; 罗浩; 李智; 邵建伟
Original assignee: Nanjing Mulai Laser Technology Co ltd
Current assignee: Nanjing Mulai Laser Technology Co ltd
Priority date: 2022-07-20
Filing date: 2022-07-20
Publication date: 2023-02-10
Anticipated expiration: 2032-07-20

Abstract

The utility model provides an optical fiber demodulation appearance calibration equipment, include: the light source emits a wide-spectrum light source; the non-polarization-maintaining fiber circulator receives an optical signal emitted by the light source and inputs the optical signal to the 1 × N optical switch; the optical signal output by the 1 × N optical switch is also received and input to the 1 × N optical splitter; 1, the N optical switch controls and switches a transmission channel of an optical signal, the output optical signal is incident to the fiber grating filter, and narrow-band light reflected by the fiber grating filter is received; the fiber grating filter reflects narrow-band light with a wavelength meeting specific conditions, and constant temperature regulation and control are performed through a temperature control device; the 1 x N optical splitter splits the light beam into N channels with equal intensity, and transmits the light beam to the optical fiber demodulator. The utility model discloses equipment can reduce because manual operation inconsistent with because of damage or dirty calibration error that arouses after the plug of jumper head is many times, improves stability and accuracy, reduces calibration time, convenient to use.

Description

Optical fiber demodulator calibration equipment

Technical Field

The utility model belongs to the technical field of the optical fiber demodulation appearance calibration equipment, in particular to optical fiber demodulation appearance calibration equipment.

Background

The fiber grating demodulator is one of key devices of a fiber sensing system, the fiber sensing system mainly comprises a fiber grating sensor and a signal demodulation system, the fiber grating sensor converts measured physical quantity into wavelength information, and the signal demodulation system needs to demodulate the wavelength information, wherein the fiber grating demodulator is a core device of the signal demodulation system.

In practical application, the optical characteristics of the internal devices of the fiber grating demodulator are slightly different, and the finally demodulated wavelength information is not completely the same, so that each fiber grating demodulator needs to be calibrated independently, and the functional relationship between the wavelength of each demodulator and the measured physical quantity is found through calibration, so that the measurement of a series of physical quantities such as temperature, strain and vibration is completed.

At present, calibration is carried out by manually plugging and unplugging the equal-wavelength interval sensors, different wavelengths correspond to corresponding numerical values in the demodulator, the sensors are sequentially plugged and unplugged from each other in the order from small to large in wavelength, and finally, the numerical relationship corresponding to the full-range wavelength of the demodulator is obtained, so that the calibration of the fiber bragg grating demodulator is completed. Although the scheme has simple principle and simple and convenient operation, the following disadvantages exist: firstly, the calibration of the demodulator is influenced by light intensity, the plugging and unplugging times of the optical fiber jumper wire head are limited, the jumper wire head is damaged after being plugged and unplugged for multiple times, the accuracy of the light intensity is influenced, and the calibration accuracy of the demodulator is greatly influenced finally; secondly, the plugging and unplugging sensor needs real-time manual operation, the light intensity stability is poor, and the consistency of plugging and unplugging every time is ensured; thirdly, the working time is calibrated once, and whether the data is accurate or not cannot be fed back in real time, if improper operation or omission occurs, the whole calibration is invalid, and therefore recalibration is needed.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: in order to solve the defects of the prior art, the utility model provides an optical fiber demodulation appearance calibration equipment.

The technical scheme is as follows: the utility model provides an optical fiber demodulator calibration device, which comprises a light source, a non-polarization maintaining optical fiber circulator, a 1X N optical switch, an optical fiber grating filter, a temperature control device and a 1X N optical splitter which are arranged in sequence;

the light source emits a wide-spectrum light source;

the non-polarization-maintaining fiber circulator receives an optical signal emitted by the light source and inputs the optical signal to the 1 × N optical switch; the optical signal output by the 1 × n optical switch is also received and input to the 1 × n optical splitter;

1, the N optical switch controls and switches a transmission channel of an optical signal, the output optical signal is incident to the fiber grating filter, and narrow-band light reflected by the fiber grating filter is received;

the fiber grating filter reflects narrow-band light with a wavelength meeting specific conditions, and constant temperature regulation and control are performed through a temperature control device;

the 1 x N optical splitter splits the light beam into N channels with equal intensity, and transmits the light beam to the optical fiber demodulator.

As preferred or specific embodiments:

the light source is selected from an ASE light source.

The transmission direction of the non-polarization-maintaining optical fiber circulator is irreversible, and if an optical signal is input from the port (1), the port (2) is output; if the input is from the port (2), the output is from the port (3).

The 1 x N optical switch has a plurality of selectable transmission ports.

The fiber Bragg grating filter can reflect light meeting the Bragg condition, and light with other wavelengths passes through the fiber Bragg grating filter, wherein the Bragg condition is as follows: λ =2neff · Λ, λ being the wavelength satisfying the condition, neff · being the refractive index of the fiber grating, and Λ being the period of the fiber grating.

The fiber grating filter consists of 25 FBGs which are arranged at equal intervals in sequence from small to large.

Each FBG of the fiber grating filter is subjected to glue sealing and aging.

The temperature control device is selected from TEC temperature control.

N channels of the 1 × N optical splitter correspond to all channels of the optical fiber demodulator needing to be calibrated

Has the beneficial effects that: compared with the prior art, the utility model has the advantages of it is following:

1. the mode that the optical switch automatically switches the wavelength of the FBG is adopted, the mode that personnel insert and pull the FBG manually is replaced, and calibration errors caused by inconsistent manual operation and damage or dirt after multiple times of inserting and pulling of the jumper are reduced.

2. The light intensity and the wavelength of the FBG adopting the mode are always in a stable state, so that the calibration stability and the calibration accuracy of the demodulator are greatly improved.

3. The labor is saved, the working time is saved, the calibration time is reduced, and the personnel are not required to operate the device according to the time.

4. By adopting the mode, the light emitting power of the ASE light source is adjusted according to different calibration requirements, and simultaneous calibration of N demodulator devices can be achieved.

5. The scheme has the characteristics of low cost, convenient use and high stability.

Drawings

Fig. 1 is the utility model discloses optical fiber demodulation appearance calibration equipment's schematic structure diagram.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

Examples

As shown in fig. 1, the optical path schematic diagram for calibrating the optical fiber demodulator is sequentially provided with:

the ASE light source 1 is a wide-spectrum light source based on erbium-doped gain fiber amplified spontaneous radiation, and the output of the ASE light source has the characteristics of good stability, wide spectrum, high output power and the like; the light source used in this patent is produced by Pege technologies, inc., and has a model of BG-ASE-M3-C-1dB-17dBm-0.9L-1M-FC/APC.

A non-polarization-maintaining optical fiber circulator 2, which is an optical device with an irreversible signal transmission direction, wherein if an optical signal is input from a port (1), a port (2) is output; if the input is from the port (2), the output is from the port (3), and the output loss is very small; the devices used in this patent are provided by optical library technology, model number FCIR-55-2-L-1.

1 an optical switch 3, an optical device having a plurality of selectable transmission ports, for controlling switching of transmission channels of optical signals; the optical switch used in this patent is provided by ilong technologies, inc, and is of the type MEMS-2-nx 1-SM-AC-APC.

The fiber grating type filter 4, the fiber grating is also called FBG, the FBG is a special optical diffraction device, and can reflect the light satisfying the Bragg condition, and the light with the rest wavelengths will pass through, wherein the Bragg condition is as follows: λ =2neff · Λ, λ being the wavelength satisfying the condition, neff being the refractive index of the fiber grating, and Λ being the period of the fiber grating. Wherein, the FBG in the patent is provided by the science and technology company Limited of the Saint Hippocampus and has the model number AG-15XX-90.0-0.5-15-SP. And integrally packaging the FBGs with a plurality of wavelengths which are arranged at equal intervals from small to large, wherein the central wavelength range is 1546-1558 nm, and 25 FBGs are obtained at an interval of 0.5 nm. If the central wavelength of the FBG is not packaged, it is difficult to keep the central wavelength stable, and the wavelength of the FBG is degraded and cannot be used after packaging because the characteristics of the FBG and the stress after packaging are not completely released. Through a series of operations such as dispensing curing, aging and packaging anti-vibration design, the stability of the wavelength of the whole device is ensured.

The FBG is sensitive to stress and temperature at the same time, and the FBG can only be affected by the stress of the fiber grating filter 4, so that the temperature of the fiber grating filter 4 is regulated and controlled at a constant temperature through the TEC temperature control 5.

1 x N optical splitter 6, an optical device capable of splitting light beams into N channels with equal intensity to realize parallel transmission; the optical splitter used in this patent is available from aerospace fiber systems, inc. under the model number 82.072914-001.

The optical fiber demodulator 7 is a device for collecting and processing wavelength data, can be used after being calibrated, and is provided by the optical technology company Limited.

Broadband light is sent by ASE light source 1, gets into 1 xN photoswitch 3 through non-polarization maintaining fiber circulator 2, incides to fiber grating formula filter 4, can reflect the narrow band light that satisfies specific condition wavelength, and FBG itself receives the influence of temperature and stress easily, needs to glue it and seals, controls fiber grating formula filter 4 through TEC temperature control 5 and carries out constant temperature. The narrow-band light reflected by the FBG passes through the 1 × n optical switch 3, passes through the non-polarization-maintaining fiber circulator 2, then enters the 1 × n optical splitter 6, and finally enters the fiber demodulator 7.

The fiber grating filter 4 is composed of 25 FBGs with equal wavelength interval and arranged in sequence from small to large, the wavelengths of the FBGs can be marked as numbers 1-25 respectively from small to large, each FBG is subjected to glue sealing and aging, and the wavelength does not change at any time under the state of stable temperature; the 1 x N optical switch 3 has the function of selecting FBG, has the functions of selecting channels, controlling the retention time of each channel and setting the cycle time of each channel, can finish the calibration of the fiber grating demodulator under different temperature cycles under the condition of unmanned supervision while ensuring that the channels can be switched to the wavelengths of the FBGs at the same time, and the N channels of the 1 x N optical splitter 6 correspond to the channels needing to calibrate the fiber grating demodulator, thereby ensuring the calibration accuracy of each channel.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The calibration equipment of the fiber bragg grating demodulator is characterized by comprising a light source (1), a non-polarization-maintaining fiber circulator (2), a 1 x N optical switch (3), a fiber bragg grating type filter (4), a temperature control device (5) and a 1 x N optical splitter (6) which are sequentially arranged;

the light source (1) emits a broad spectrum light source;

the non-polarization-maintaining optical fiber circulator (2) receives an optical signal emitted by the light source (1) and inputs the optical signal to the 1 × N optical switch (3); the optical signal output by the 1 × n optical switch (3) is also received and input to the 1 × n optical splitter (6);

the 1 × N optical switch (3) controls a transmission channel for switching optical signals, the output optical signals are incident to the fiber grating filter (4), and narrow-band light reflected by the fiber grating filter (4) is received;

the fiber grating filter (4) reflects narrow-band light meeting the condition wavelength, and constant temperature regulation and control are carried out through the temperature control device (5);

the 1 x N optical splitter (6) splits the light beam into N channels with equal intensity and transmits the light beam to the optical fiber demodulator.

2. The fiber grating demodulator calibration device according to claim 1, wherein the light source (1) is selected from ASE light sources.

3. The fiber grating demodulator calibration device according to claim 1, wherein the transmission direction of the non-polarization-maintaining fiber circulator (2) is irreversible, and if an optical signal is input from the port (1), the port (2) is output; if the input is from the port (2), the output is from the port (3).

4. The fiber grating demodulator calibration device according to claim 3, wherein the 1 x N optical switch (3) has a plurality of selectable transmission ports.

5. The fiber grating demodulator calibration device according to claim 1, wherein the fiber grating filter (4) is capable of reflecting light satisfying a Bragg condition, and light of the remaining wavelengths will pass through, wherein the Bragg condition is: λ =2neff · Λ, λ being the wavelength satisfying the condition, neff · being the refractive index of the fiber grating, and Λ being the period of the fiber grating.

6. The fiber grating demodulator calibration device according to claim 1, wherein the fiber grating filter (4) is composed of FBGs with 25 wavelengths arranged in sequence from small to large.

7. The fiber grating demodulator calibration device according to claim 1, wherein each FBG of the fiber grating filter (4) is glued and aged.

8. The fiber grating demodulator calibration device according to claim 1, wherein the temperature control device (5) is selected from TEC temperature control.

9. The fiber grating demodulator calibration device according to claim 1, wherein the N channels of the 1 x N optical splitter (6) correspond to respective channels of the fiber grating demodulator to be calibrated.