CN220490091U - Testing device for frequency characteristic of optical fiber demodulator - Google Patents

Abstract

The device for testing the frequency characteristic of the optical fiber demodulator comprises a standard grating module, a high-speed optical switch, a trigger module, a digital signal processing unit, a power module, a temperature control module and a demodulator to be tested, wherein the digital signal processing unit is connected with the trigger module and is used for sending an instruction to the trigger module; the triggering module is respectively connected with the high-speed light-on demodulator and the tested demodulator through coaxial cables; the high-speed optical switch output end is connected with the standard grating module, and the high-speed optical switch input end is connected with the demodulator to be tested. Compared with the prior art, the utility model has the advantages that: the switching capability of the high-speed optical switch is utilized to simulate the situation of rapid wavelength change of the single-channel fiber bragg grating sensor, and whether the frequency response characteristic of the signal obtained by the demodulator meets the requirement is judged by analyzing the signal obtained by the demodulator, so that the problem that the frequency characteristic of the dynamic bragg grating demodulator cannot be calibrated is solved.

Description

Testing device for frequency characteristic of optical fiber demodulator

Technical Field

The utility model relates to the technical field of frequency characteristic test, in particular to a test device for frequency characteristics of an optical fiber demodulator.

Background

In recent years, a fiber grating temperature and pressure sensor-based measurement system is widely applied to the fields of electric power sources, petrochemical industry, rail transit, tunnel bridges and the like, and becomes a bright spot for economic growth, and related technologies become hot spots for people to study. The fiber grating demodulation technology is to analyze and process the monitored signals to obtain the change conditions of various external parameters, so as to achieve the purpose of signal measurement, and therefore, a demodulation system with high precision and high reliability has very important significance on the fiber grating sensing system.

However, how to judge whether the frequency response characteristics meet the requirements or not and whether the frequency response capability is good or not so as to rapidly detect different wavelength signals is needed to solve the problem that the frequency characteristics of the dynamic grating demodulator cannot be tested at present.

Disclosure of Invention

The utility model aims to overcome the technical defects and provide a testing device for the frequency characteristic of an optical fiber demodulator, which can simply and effectively test the frequency response characteristic of the demodulator.

In order to solve the technical problems, the technical scheme provided by the utility model is as follows: the device for testing the frequency characteristic of the optical fiber demodulator comprises a standard grating module, a high-speed optical switch, a trigger module, a digital processing unit, a power module, a temperature control module and a tested demodulator, wherein the digital processing unit is connected with the trigger module and is used for sending an instruction to the trigger module; the triggering module is respectively connected with the high-speed optical switch and the tested demodulator through coaxial cables; the high-speed optical switch output end is connected with the standard grating module, and the high-speed optical switch input end is connected with the demodulator to be tested.

Further, the temperature control module comprises a temperature control cavity and a temperature sensor.

Furthermore, two sides in the temperature control cavity are respectively provided with a temperature sensor for detecting the temperature of the greenhouse cavity.

Furthermore, the standard grating module is arranged in the temperature control cavity, and the fiber grating is sensitive to temperature, so that the constant temperature control is performed through the temperature cavity.

Furthermore, the standard grating module is a wavelength signal device, and four fiber gratings with center wavelength differences of 0.3nm and different intervals are arranged.

Further, the high-speed optical switch is a quarter bidirectional optical switch.

Furthermore, the digital processing unit can be used for controlling the trigger module and the high-speed optical switch to work by inputting parameters from the outside.

Further, the power module is connected with the digital processing unit and the temperature control module.

Compared with the prior art, the utility model has the advantages that: according to the utility model, through the switching capability of the high-speed optical switch, the situation of simulating the rapid change of the wavelength of the single-channel fiber bragg grating sensor is achieved, different switching frequencies can be set according to the needs, so that different wavelength signals are created, if the demodulator has good frequency response capability, the different wavelength signals can be rapidly detected, and the signal wavelength is consistent with the standard grating module of the device. And judging whether the frequency response characteristic of the signal obtained by the demodulator meets the requirement or not by analyzing the signal obtained by the demodulator, and solving the problem that the frequency characteristic of the dynamic grating demodulator cannot be calibrated.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

As shown in the figure: 1. the system comprises a standard grating module, a high-speed optical switch, a triggering module, a digital processing unit, a power module, a temperature control module, a measured demodulator, a temperature control cavity and a temperature sensor, wherein the standard grating module, the high-speed optical switch, the triggering module, the digital processing unit, the power module, the temperature control module, the measured demodulator, the temperature control cavity and the temperature sensor are arranged in sequence, and the standard grating module, the high-speed optical switch, the triggering module, the digital processing unit, the temperature control module and the temperature sensor are arranged in sequence.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

In the description of the embodiments of the present utility model, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate an azimuth or a positional relationship based on that shown in the drawings, or an azimuth or a positional relationship in which the product of the present utility model is conventionally put when used, it is merely for convenience of describing the present utility model and simplifying the description, and it does not indicate or imply that the apparatus or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal," "vertical," "overhang" and the like, if any, do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present utility model, "plurality" means at least 2.

In the description of the embodiments of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The present utility model will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1, a testing device for frequency characteristics of an optical fiber demodulator comprises a standard grating module 1, a high-speed optical switch 2, a trigger module 3, a digital processing unit 4, a power module 5, a temperature control module 6 and a tested demodulator 7, wherein the digital processing unit 4 is connected with the trigger module 3 and is used for sending instructions to the trigger module 3; the triggering module 3 is respectively connected with the high-speed optical switch 2 and the tested demodulator 7 through coaxial cables; the output end of the high-speed optical switch 2 is connected with the standard grating module 1, and the input end of the high-speed optical switch 2 is connected with the tested demodulator 7.

In this embodiment, the digital processing unit 4 includes a digital processing program, and parameters can be input from the outside to control the operation of the trigger module 3 and the high-speed optical switch 2. The digital processing unit 4 receives setting parameters including, but not limited to (optical switch driving mode, switching frequency f, trigger start/stop time); the trigger module 3 comprises a TTL device for sending a TTL trigger signal, and two connecting ends of the TTL trigger signal are respectively connected with the high-speed optical switch 2 and the tested demodulator 7; the output end of the high-speed optical switch 2 is connected with the standard grating module 1, and the input end of the high-speed optical switch 2 is connected with the demodulator 7 to be tested; the standard grating module 1 is arranged into four fiber gratings with different center wavelengths and 0.3nm intervals, and the four fiber gratings with different center wavelengths are respectively connected to an output channel of the high-speed optical switch 2; the temperature control module 6 comprises a temperature control cavity 8 and temperature sensors 9, wherein two temperature sensors 9 are respectively arranged on two sides in the temperature control cavity 8 and are used for detecting the temperature of the greenhouse cavity 8.

In the implementation of the utility model, the power supply module 5 is turned on, the switching frequency f of the high-speed optical switch 2 and the triggering start/stop time of the triggering module 3 are input in the program of the digital processing unit 4, and the switching frequencies of the high-speed optical switch 2 are set to be 5/f, 3/f, 2/f and f in the digital processing unit 4. Simultaneously, the temperature control module 6 is started, the temperature of the temperature control cavity 8 is set to be 25 ℃, the trigger module 3 is started, the trigger module 3 sends out TTL signals, two connecting ends of the TTL signals are connected with the high-speed optical switch 2, and the other connecting end is connected with the tested demodulator 7. The triggering module 3 commands the demodulator 7 to be tested and the high-speed optical switch 2 to start working synchronously. Through the switching capability of the high-speed optical switch 2, four fiber gratings with different center wavelengths can be continuously and automatically switched, so that the situation of simulating the rapid change of the wavelength of a single-channel fiber grating sensor is achieved, when the tested demodulator 7 receives that the frequencies of the high-speed optical switch 2 are 5/f, 3/f, 2/f and f respectively, the tested demodulator 7 can acquire four different center wavelength signals to obtain a graph of the change of the four wavelengths along with time, and the data acquired by the tested demodulator 7 are stored in the tested demodulator 7 or other computers. And comparing the curve graphs of the time changes of the four wavelengths acquired by the tested demodulator 7 with the curve graphs of the time changes of the center wavelengths of the standard grating module 1 under the corresponding different switching frequencies of the high-speed switch 2.

The utility model and its embodiments have been described above with no limitation, and the actual construction is not limited to the embodiments of the utility model as shown in the drawings. In short, if one of ordinary skill in the art is informed by this disclosure, the structural mode and the embodiment similar to the technical scheme are not creatively designed without departing from the gist of the present utility model and all the structural mode and the embodiment are considered to be in the protection scope of the present utility model _。

Claims (7)

1. A testing arrangement for optical fiber demodulator frequency characteristic, characterized by that: the device comprises a standard grating module (1), a high-speed optical switch (2), a trigger module (3), a digital processing unit (4), a power module (5), a temperature control module (6) and a tested demodulator (7), wherein the digital processing unit (4) is connected with the trigger module (3) and is used for sending instructions to the trigger module (3); the triggering module (3) is respectively connected with the high-speed optical switch (2) and the tested demodulator (7) through coaxial cables; the output end of the high-speed optical switch (2) is connected with the standard grating module (1), and the input end of the high-speed optical switch (2) is connected with the demodulator (7) to be tested.

2. A test apparatus for frequency characteristics of an optical fiber demodulator according to claim 1, wherein: the temperature control module (6) comprises a temperature control cavity (8) and a temperature sensor (9).

3. A test apparatus for frequency characteristics of an optical fiber demodulator according to claim 2, wherein: two temperature sensors (9) are respectively arranged at two sides in the temperature control cavity (8).

4. A test apparatus for frequency characteristics of an optical fiber demodulator according to claim 1, wherein: the standard grating module (1) is arranged in the temperature control cavity (8).

5. A test apparatus for frequency characteristics of an optical fiber demodulator according to claim 1, wherein: the standard grating module (1) is a wavelength signal device and is arranged as four fiber gratings with center wavelengths different by 0.3nm but different.

6. A test apparatus for frequency characteristics of an optical fiber demodulator according to claim 1, wherein: the high-speed optical switch (2) is a one-quarter bidirectional optical switch.

7. A test apparatus for frequency characteristics of an optical fiber demodulator according to claim 1, wherein: the power module (5) is connected with the digital processing unit (4) and the temperature control module (6).