Negative temperature compensation packaging device of passive optical fiber

Abstract

The utility model discloses a negative temperature compensation packaging device of a passive optical fiber, which comprises a thin metal shell, a specially-made aluminum block, a specially-made invar metal block, a compensation section, a fixing nut, an optical fiber, a v-shaped groove and a clamping groove, and is characterized in that the thin metal shell is matched with the specially-made aluminum block and the specially-made invar metal block to fix and place an optical fiber grating; the special aluminum block and the special invar metal block are both provided with clamping grooves, the clamping grooves in the two parts are matched, each metal block is provided with a compensation section and a v-shaped groove, the optical fiber can be embedded into the v-shaped groove and is kept in contact with the v-shaped groove, and the fixing nut enables the relative positions of the special aluminum block and the special invar metal block to be kept fixed. The v-shaped grooves are formed in the special aluminum block and the special invar metal block, and the optical fibers are placed in the v-shaped grooves of the two metal blocks; according to the utility model, the temperature compensation effect of the metal packaging device is utilized to make up the temperature rise expansion of the grating, and the stability of the length of the optical fiber grating region is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber devices, in particular to a negative temperature compensation packaging device for passive optical fibers. Background Art

[0002] An optical fiber grating is a diffraction grating formed by axially periodically modulating the refractive index of the optical fiber core through a certain method. It is a passive filtering device. Since the grating optical fiber has the advantages of small size, low fusion loss, full compatibility with optical fibers, and the ability to be embedded in intelligent materials, and its resonant wavelength is sensitive to changes in external environments such as strain, refractive index, and concentration, it has been widely used in the fields of optical fiber communication and sensing. These application fields have high requirements for the reliability, structural stability, and noise characteristics of optical fiber lasers. The Bragg grating in a general optical fiber laser is vulnerable to environmental disturbances, and the length of the grating expands with the increase in temperature, which will seriously deteriorate the performance of the optical fiber laser. Therefore, it is of great significance to take further technical means to fix and package the optical fiber grating in the optical fiber laser and study the relevant packaging structures and packaging materials. Currently, the methods for compensating optical fiber grating sensors are generally divided into two categories, namely active temperature compensation and passive temperature compensation. Among them, active compensation means adding a control circuit outside the part of the sensor to adjust the temperature change to achieve temperature compensation; this method has a relatively complex structure and is not conducive to implementation. Among them, passive compensation means starting from the packaging structure and not involving an external regulation circuit, such as using a material with a negative thermal expansion coefficient to achieve temperature compensation.

[0003] For the packaging device of passive compensation, Patent (CN113865745 A) proposed: a passive optical fiber grating temperature compensation structure and method. Its basic principle is to package by using two materials with different positive thermal expansion coefficients, and fix the two ends of the grating area of the optical fiber laser on two different materials respectively. However, this packaging technology can only eliminate the influence brought by the ambient temperature and cannot eliminate the frequency drift caused by the self-heating of the optical fiber grating. When the optical fiber grating is in use, a large amount of heat will be generated in the grating part, ultimately causing the frequency of the emitted light to fluctuate. Summary of the Utility Model

[0004] The purpose of the present utility model is to provide a negative temperature compensation packaging device for a passive optical fiber in view of the deficiencies of the prior art. The device includes a thin metal shell, a special aluminum block, a special invar metal block, a compensation section, a fixing nut, an optical fiber, a V-groove, and a card slot. The thin metal shell cooperates with the special aluminum block and the special invar metal block to fix and place the fiber grating. Card slots are provided on both the special aluminum block and the special invar metal block, and the card slots on the two parts are aligned. A compensation section and a V-groove are provided on each metal block. The optical fiber can be embedded in the V-groove and kept in contact with the V-groove. The fixing nut keeps the relative positions of the special aluminum block and the special invar metal block fixed. The V-groove is provided on the special aluminum block and the special invar metal block, and the optical fiber is placed in the V-grooves of the two metal blocks. The card slot is provided on the special aluminum block and the special invar metal block to achieve the purpose of fixation.

[0005] Preferably, the thin metal shell is divided into an upper shell and a lower shell. Threads are provided at both ends of the upper shell and the lower shell and are fixed by a fixing nut. A metal step is provided at the fixing position.

[0006] Preferably, a special aluminum block metal step and a special invar metal step are respectively provided on the special aluminum block and the special invar metal block, and the two metal steps cooperate with the metal step of the thin metal shell for fixation.

[0007] Preferably, a silica gel protective sleeve for buffering and sealing is provided between the thin metal shell and the fixing nut.

[0008] Preferably, fixing rubber pads are fixed on the special aluminum block and the special invar metal block, and the optical fiber is pressed tightly by the fixation of the fixing nut.

[0009] Compared with the prior art, the beneficial effects of the present utility model are as follows: The present utility model adopts a passive fiber grating packaging device. The temperature compensation packaging device is composed of two metal materials with different coefficients of thermal expansion. Through the structural design, when the overall temperature of the device changes, the length of the grating can be kept unchanged, thus greatly improving the frequency stability of the light output of the fiber laser. The device is simpler, smaller in size, and more compact.

[0010] At the same time, the present utility model utilizes the temperature compensation effect of the metal packaging device to make up for the temperature rise expansion of the grating, ensuring the stability of the length of the fiber grating area. At the same time, the device is easy to disassemble, uses a completely sealed structure, and the structure is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. They are used together with the embodiments of the present utility model to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0012] Figure 1Structural diagram of the present utility model;

[0013] Figure 2 Internal structural diagram of the present utility model.

[0014] In the figure: 1, thin metal shell; 2, special aluminum block; 3, special invar metal block; 4, compensation section; 5, fixing nut; 6, silicone protective sleeve 6; 7, optical fiber; 8, fixing rubber pad; 9, V-shaped groove; 10, card slot; 101, upper housing; 102, lower housing; 103, outer shell metal step; 201, special aluminum block metal step; 301, special invar metal step. Specific implementation manner

[0015] The technical solution of the present utility model will be described in detail below with reference to the accompanying drawings, but the protection scope of the present utility model is not limited to the embodiments.

[0016] Refer to Figure 1 and Figure 2, a negative temperature compensation packaging device for a passive optical fiber of the present utility model, includes a thin metal shell 1, a special aluminum block 2, a special invar metal block 3, a compensation section 4, a fixing nut 5, a silica gel protective sleeve 6, an optical fiber 7, a fixing rubber pad 8, a V-shaped groove 9, and a card slot 10. The thin metal shell 1 is divided into an upper shell 101 and a lower shell 102, with threads at both ends, and can be fixed by the nut 5. There is a shell metal step 103 at the fixing position, which cooperates with the special aluminum block 2 and the special invar metal block 3 to fix and place the fiber grating 7; the special aluminum block 2 and the special invar metal block 3 are each divided into two parts for combination, each provided with a card slot 10, each part can be completely fitted, and is provided with a special aluminum block metal step 201 and a special invar metal step 301, which cooperate with the metal shell step 103. Each metal block is provided with a compensation section 4 and a V-shaped groove 9, and the fiber grating 7 can be embedded in the V-shaped groove 9 and maintain good contact with the V-shaped groove 9; the compensation section 4 enables the special aluminum block 2 and the special invar metal block 3 to have an expansion space to prevent the device from deforming; the fixing nut 5 fixes the device structure to keep the relative positions of the special aluminum block 2 and the special invar metal block 3 fixed; the silica gel protective sleeve 6 protects the optical fiber 7 and is placed between the thin metal shell 1 and the fixing nut 5, while playing a buffering and sealing role. The optical fiber 7 passes through the silica gel protective sleeve 6, with one end of the silica gel protective sleeve in the V-shaped groove 9 of the metal block and the other end passing through the fixing nut 5; the fixing rubber pad 8 is fixed on the special aluminum block 2 and the special invar metal block 3, and presses the optical fiber 7 through the fixing of the fixing nut 5; the V-shaped groove 9 is machined on the special aluminum block 2 and the special invar metal block 3 by mechanical processing. The fiber grating 7 is placed in the V-shaped grooves 9 of the two matched metal blocks, the special aluminum block 2 and the special invar metal block 3, to ensure sufficient thermal contact with the special aluminum block 2 and the special invar metal block 3; the card slot 10 is provided on both the special aluminum block 2 and the special invar metal block 3 for the purpose of fixing. The positional relationship of the above components is as follows: The special aluminum block 2 and the special invar metal block 3 each have two parts with exactly the same size and shape. Fixed card slots 10 are provided on all four metal blocks. The special aluminum block 2 and the special invar metal block 3 completely fit the thin metal shell 1. The surfaces of the special aluminum block 2 and the special invar metal block 3 are engraved with V-shaped grooves 9, and the width of the V-shaped groove 9 corresponds to the thickness of the optical fiber 7 to ensure good thermal contact with the fiber grating area. The two parts of the same metal material are placed on the same side. Through the shell metal step 103, the special aluminum block metal step 201, the special invar metal step 301, the card slot 10, and the fixing nut 5, the length of the fiber grating 7 is kept fixed; the thin metal shell 1 and the internal components are fixed and pressed by threads with the nut 5, and the relative positions of the two internal metal blocks, the special aluminum block 2 and the special invar metal block 3, are kept fixed;

[0017] The optical fiber grating 7 is fixed by the fixing rubber pads 8 fixed on the special aluminum block 2 and the special invar metal block 3. After tightening the nut 5, the internal rubber pad 8 presses and fixes the optical fiber.

[0018] In the present utility model, since the thermal expansion coefficient of the special aluminum block 2 is much larger than that of the special invar metal block 4, when the optical fiber expands due to heat or the overall ambient temperature rises, the A end of the optical fiber will move closer to the B end due to the expansion of the special aluminum block 2, resulting in a decrease in the distance between the A end and the B end, and finally forming an overall negative thermal expansion effect.

[0019] As described above, although the present utility model has been shown and described with reference to specific preferred embodiments, it should not be construed as a limitation of the present utility model itself. Various changes can be made to it in form and detail without departing from the spirit and scope of the present utility model defined by the appended claims.

Claims

1. A negative temperature compensation packaging device for a passive optical fiber, characterized in that: It includes a thin metal shell, a special aluminum block, a special invar metal block, a compensation section, a fixing nut, an optical fiber, a V-groove, and a card slot. The thin metal shell cooperates with the special aluminum block and the special invar metal block to fix and place the fiber grating. Card slots are provided on both the special aluminum block and the special invar metal block, and the card slots on the two parts are aligned. Each metal block is provided with a compensation section and a V-groove. The optical fiber can be embedded in the V-groove and keep in contact with the V-groove. The fixing nut keeps the relative positions of the special aluminum block and the special invar metal block fixed. The V-groove is provided on the special aluminum block and the special invar metal block, and the optical fiber is placed in the V-grooves of the two metal blocks. The card slot is provided on the special aluminum block and the special invar metal block to achieve the purpose of fixation.

2. The negative temperature compensation packaging device for a passive optical fiber according to claim 1, characterized in that: The thin metal shell is divided into an upper shell and a lower shell. The two ends of the upper shell and the lower shell have threads and are fixed by a fixing nut, and a metal step is provided at the fixing position.

3. The negative temperature compensation packaging device for a passive optical fiber according to claim 2, wherein: The special aluminum block and the special invar metal block are respectively provided with a special aluminum block metal step and a special invar metal step, and the two metal steps cooperate with the metal step of the thin metal shell for fixation.

4. A negative temperature compensation packaging device for a passive optical fiber according to claim 3, characterized in that: A silica gel protective sleeve for buffering and sealing is provided between the thin metal shell and the fixing nut.

5. A negative temperature compensation packaging device for a passive optical fiber according to claim 4, characterized in that: Fixing rubber pads are fixed on the special aluminum block and the special invar metal block, and the optical fiber is pressed tightly by the fixation of the fixing nut.

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