Small-size packaged two-stage isolator

Abstract

The utility model relates to an optical transmission technology, in particular to a small-size packaged two-stage isolator, which comprises an outer metal tube, two single-fiber collimators, two isolator cores and a glass tube, the outer metal tube is positioned on the outermost layer, the two single-fiber collimators are symmetrically arranged on two sides in the outer metal tube, and the two isolator cores are positioned in the glass tube. The two isolator cores are respectively a first isolator core and a second isolator core and are arranged between the two single-fiber collimators, and the first isolator core and the second isolator core are arranged in parallel; and the glass tube is fixed on the inner wall of the outer metal tube and is used as a connecting bridge for fixedly connecting the two single-fiber collimators and the two isolator cores. The two single-fiber collimators are arranged in the outer metal tube, so that the transmission distance of light beams is increased, and the two-stage isolator has the effect of forward light transmission and reverse isolation by means of the two isolator cores; and the two isolator cores and the two single-fiber collimators are packaged in the outer metal tube by using the glass tube as a connecting bridge.

Description

Technical Field

[0001] This utility model relates to an optical transmission technology, specifically a small-sized packaged two-stage isolator. Background Technology

[0002] Fiber optic isolators are used in advanced fiber optic communication and sensing systems. Their function is to prevent adverse effects on the light source and optical path system caused by back-reflected light due to various reasons. For example, installing optical isolators at both ends of the doped fiber in a fiber optic amplifier can improve the operating stability of the fiber optic amplifier. Without them, back-reflected light would enter the signal source (laser), causing severe fluctuations in the signal.

[0003] Miniaturization has always been a development trend for passive optical devices, as smaller size means greater applicability to more compact and wider range of applications. Fiber optic isolators, as common passive optical devices, have seen their package size decrease in recent years thanks to various improvements and optimizations.

[0004] Due to limitations in physical structure, the smallest package size currently available on the market is still limited, making it impossible to achieve even smaller package structures. Utility Model Content

[0005] The purpose of this invention is to provide a small-sized packaged two-stage isolator to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A small-size packaged two-stage isolator includes:

[0008] An outer metal tube, which is the outermost layer, is used for the outermost protection of the device;

[0009] Two single-fiber collimators are symmetrically arranged on both sides inside the outer metal tube. The single-fiber collimators are used to collimate the small-mode beam transmitted in the fiber into a large-mode beam so as to transmit over a longer distance.

[0010] Two isolator cores, namely a first isolator core and a second isolator core, are placed between the two single-fiber collimators, with the first isolator core and the second isolator core arranged side by side;

[0011] A glass tube, fixed to the inner wall of the outer metal tube, serves as a connecting bridge for the fixed connection of the two single-fiber collimators and the two isolator cores.

[0012] The small-sized packaged two-stage isolator as described above: the single-fiber collimator includes a connecting tube, a single-fiber pigtail extending into and fixed to the connecting tube from one end of the connecting tube, and a self-focusing lens extending into and fixed to the connecting tube from the other end of the connecting tube.

[0013] The small-sized packaged two-stage isolator described above: a single-hole capillary tube is inserted inside the single-fiber pigtail, and an optical fiber is inserted inside the single-hole capillary tube, with the optical fiber bonded and fixed to the single-hole capillary tube.

[0014] The small-sized packaged two-stage isolator described above: one end of the optical fiber is used as a pigtail, and the other end is ground into a bevel with an angle of 8°, and an anti-reflection coating is deposited on the bevel.

[0015] One end of the self-focusing lens is also a slope with an angle of 8°, and the other end is a plane. Both ends of the self-focusing lens are coated with anti-reflective coatings.

[0016] The small-sized packaged two-stage isolator as described above: the isolator core includes a Faraday plate, a wedge-angle lens is provided on each side of the Faraday plate, and a magnetic ring is provided on the outer periphery of the Faraday plate.

[0017] The small-sized packaged dual-stage isolator described above: the wedge lens is made of niobium lithium oxide crystal material, the wedge angle is 13°, and the optical axis is in the light-transmitting right-angled plane, forming a 22.5° angle with the right-angled side.

[0018] The small-sized packaged two-stage isolator as described above: the first isolator core and the second isolator core are axially offset within the glass tube; the first isolator core and the second isolator core are deflected and offset by 45° along the axis of the glass tube.

[0019] Compared with the prior art, the beneficial effects of this utility model are: by setting two single-fiber collimators inside the outer metal tube, the transmission distance of the beam is increased, and the two isolator cores enable the double-stage isolator to have the effect of forward light transmission and reverse isolation; the two isolator cores and the two single-fiber collimators are encapsulated inside the outer metal tube by using a glass tube as a connecting bridge. Attached Figure Description

[0020] Figure 1 This is an outline drawing of a small-size packaged two-stage isolator.

[0021] Figure 2 This is a schematic diagram of the internal structure of a small-sized packaged two-stage isolator.

[0022] Figure 3 A schematic diagram of the single-fiber collimator in a small-sized packaged two-stage isolator.

[0023] Figure 4 This is a schematic diagram of the isolator core in a small-size packaged two-stage isolator.

[0024] Figure 5 This is a three-dimensional view of a wedge lens.

[0025] Figure 6 This is a diagram showing the misalignment distribution of the two isolator cores inside the glass tube.

[0026] In the diagram: 1-Outer metal tube; 2-Single fiber collimator; 3-Glass tube; 4-First isolator core; 5-Second isolator core; 6-Connecting tube; 7-Single fiber pigtail; 8-Self-focusing lens; 9-Wedge lens; 10-Faraday plate; 11-Magnetic ring. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0028] Please see Figures 1-6 As one embodiment of this utility model, the small-size packaged two-stage isolator includes:

[0029] Outer metal tube 1, which is located at the outermost layer, is made of stainless steel and is used for the outermost protection of the device;

[0030] Two single-fiber collimators 2 are symmetrically arranged on both sides inside the outer metal tube 1. The single-fiber collimators 2 are used to collimate the small-mode field beam transmitted in the fiber into a large-mode field beam so as to transmit over a longer distance.

[0031] Two isolator cores, namely the first isolator core 4 and the second isolator core 5, are placed between the two single-fiber collimators 2, with the first isolator core 4 and the second isolator core 5 arranged side by side;

[0032] The glass tube 3 is fixed on the inner wall of the outer metal tube 1 and serves as a connecting bridge for the two single fiber collimators 2 and the two isolator cores. The glass tube 3 is made of borosilicate glass.

[0033] In this invention, by setting two single-fiber collimators 2 inside the outer metal tube 1, the transmission distance of the light beam is increased, and by using two isolator cores, this double-stage isolator has the effect of forward light transmission and reverse isolation; by using a glass tube 3 as a connecting bridge, the two isolator cores and the two single-fiber collimators 2 are encapsulated inside the outer metal tube 1.

[0034] As a further embodiment of this utility model, the single-fiber collimator 2 includes a connecting tube 6, a single-fiber pigtail 7 extending from one end of the connecting tube 6 into the connecting tube 6 and fixed to the connecting tube 6, and a self-focusing lens 8 extending from the other end of the connecting tube 6 into the connecting tube 6 and fixed to the connecting tube 6.

[0035] The connecting tube 6 is a stainless steel tube used to fix and connect the single fiber pigtail 7 and the self-focusing lens 8. A single-hole capillary tube is inserted inside the single fiber pigtail 7, and an optical fiber is inserted inside the single-hole capillary tube. The optical fiber is bonded and fixed to the single-hole capillary tube.

[0036] One end of the optical fiber is used as a pigtail, and the other end is ground into a bevel with an angle of 8°, and an anti-reflection coating is deposited on the bevel.

[0037] One end of the self-focusing lens 8 is also a slope with an angle of 8°, and the other end is a plane. Both ends of the self-focusing lens 8 are coated with anti-reflective coatings.

[0038] In this embodiment, the single-fiber collimator 2 of this invention is collimated into a parallel beam by setting the inclined surface of the single-fiber pigtail 7 and the inclined surface of the self-focusing lens 8 in a parallel docking state, and setting the focal point of the self-focusing lens 8 at the docking position of the single-fiber pigtail 7 and the self-focusing lens 8, or by efficiently coupling the parallel beam emitted from the fiber end face into the fiber.

[0039] As a further embodiment of this utility model, the isolator core includes a Faraday plate 10, a wedge-angle lens 9 is provided on each side of the Faraday plate 10, and a magnetic ring 11 is provided on the outer periphery of the Faraday plate 10.

[0040] The wedge lens 9 is made of niobium lithium oxide crystal, with a wedge angle of 13°. Its optical axis lies within the light-transmitting right-angled plane, forming a 22.5° angle with the right-angled side (see reference). Figure 5 ).

[0041] In this embodiment, the thickness of the Faraday plate 10 in this invention changes with the working wavelength, and its main function is to rotate the linearly polarized light by 45°. The magnetic ring 11 is made of samarium cobalt material and provides a magnetic field for the Faraday plate 10 to work.

[0042] As a further embodiment of this invention, please refer to [link / reference]. Figure 6 The first isolator core 4 and the second isolator core 5 are axially offset within the glass tube 3;

[0043] Specifically, the first isolator core 4 and the second isolator core 5 are deflected and misaligned by 45° along the axis of the glass tube 3.

[0044] By setting up such a physical structure, it is possible to rotate linearly polarized light by 90°.

[0045] The isolator core in the small-sized packaged two-stage isolator of this utility model is assembled according to the following steps:

[0046] Step 1: Fix the Faraday plate 10 inside the magnetic ring 11;

[0047] Step 2: Fix the two wedge lenses 9 on both sides of the Faraday plate 10 respectively, and the optical axis angle of the two wedge lenses 9 is 45°.

[0048] Step 3: Fix the first isolator core 4 inside the glass tube 3;

[0049] Step 4: Place the second isolator core 5 into the glass tube 3, close to the first isolator core 4. Using the testing system and adjustment frame, rotate the second isolator core 5 4 45° relative to the first isolator core 4, and then fix it. After fixing, check from one side of the end face of the glass tube 3 that the two isolator cores are aligned. Figure 6 state.

[0050] The above embodiments are exemplary and not restrictive. Therefore, without departing from the spirit or basic characteristics of this utility model, any technical solutions that can be implemented in other specific forms are included in this utility model.

Claims

1. A small-size packaged two-stage isolator, characterized in that, include: The outer metal tube (1) is located at the outermost layer and is used for the outermost protection of the device; Two single-fiber collimators (2) are symmetrically arranged on both sides inside the outer metal tube (1). The single-fiber collimators (2) are used to collimate the small-mode beam transmitted in the fiber into a large-mode beam so as to transmit over a longer distance. Two isolator cores, namely a first isolator core (4) and a second isolator core (5), are placed between the two single-fiber collimators (2), and the first isolator core (4) and the second isolator core (5) are arranged side by side; A glass tube (3) is fixed on the inner wall of the outer metal tube (1) and serves as a connecting bridge for the two single fiber collimators (2) and the two isolators.

2. The small-size packaged two-stage isolator according to claim 1, characterized in that, The single-fiber collimator (2) includes a connecting tube (6), a single-fiber pigtail (7) extending from one end of the connecting tube (6) into the connecting tube (6) and fixed to the connecting tube (6), and a self-focusing lens (8) extending from the other end of the connecting tube (6) into the connecting tube (6) and fixed to the connecting tube (6).

3. A small-size packaged two-stage isolator according to claim 2, characterized in that, The single-fiber pigtail (7) is provided with a single-hole capillary tube, and an optical fiber is provided inside the single-hole capillary tube. The optical fiber is bonded and fixed to the single-hole capillary tube.

4. A small-size packaged two-stage isolator according to claim 3, characterized in that, One end of the optical fiber is used as a pigtail, and the other end is ground into a bevel with an angle of 8°, and an anti-reflection coating is deposited on the bevel. One end of the self-focusing lens (8) is also a slope with an angle of 8°, and the other end is a plane. Both ends of the self-focusing lens (8) are coated with anti-reflective film.

5. A small-size packaged two-stage isolator according to claim 1, characterized in that, The isolator core includes a Faraday plate (10), a wedge lens (9) is provided on each side of the Faraday plate (10), and a magnetic ring (11) is provided on the outer periphery of the Faraday plate (10).

6. A small-size packaged two-stage isolator according to claim 5, characterized in that, The wedge lens (9) is made of niobium lithium oxide crystal material, with a wedge angle of 13° and an optical axis within the light-transmitting right-angled plane, forming a 22.5° angle with the right-angled side.

7. A small-size packaged two-stage isolator according to claim 1, characterized in that, The first isolator core (4) and the second isolator core (5) are axially offset within the glass tube (3); the first isolator core (4) and the second isolator core (5) are deflected and offset by 45° along the axis of the glass tube (3).

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