Optical interface assembly and optical module

Abstract

The application discloses an optical interface assembly, which comprises a lens barrel, a lens arranged in the lens barrel, an optical socket, a fiber core arranged in the optical socket, and a light barrier arranged between the lens and the fiber core; the light transmission aperture of the light barrier is smaller than the light transmission aperture of the lens; the first end face of the fiber core opposite to the lens is arranged to be inclined to the axis of the fiber core; the return light of the light beam coupled into the fiber core through the lens and reflected by the first end face is reflected out of the light transmission aperture of the light barrier and is blocked by the light barrier. The light barrier is arranged in the optical interface assembly to block the stray light from returning to the optical device, so that the return loss of the optical interface is effectively improved, the optical crosstalk from the transmitting end of the high-speed optical module to the receiving end is reduced, and the reliability of the optical transmission system and the stability of the spectrum and power of the light source are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of passive optical devices, in particular to an optical interface assembly and an optical module. BACKGROUND

[0002] In an optical fiber transmission system, connectors, fiber end faces, optical interfaces and probe surfaces can cause Fresnel reflection. The ratio of the optical power of the reflected light to the incident light power is called return loss, which is simply referred to as return loss. The worse the return loss, the stronger the reflection in the optical fiber link. The effects of the back reflection on the system include: 1) weakening the transmitted optical signal; 2) causing interference with the incident optical signal; 3) reducing the signal-to-noise ratio in a digital transmission system. The back reflection light also returns to the light source, which can affect the light source, including: 1) causing the center wavelength of the light source to fluctuate; 2) causing the light intensity of the light source to fluctuate; 3) permanently damaging the light source. Even for FP light sources, although the back reflection has little effect on the spectral characteristics, the reflected light is amplified by the active region after being incident on the resonant cavity of the light source, and is added to the mainstream, causing the light intensity to fluctuate, which leads to RIN (Relative Intensity Noise). RIN is a noise related to the transmitting end rather than the receiving end, which will limit the maximum signal-to-noise ratio that can be obtained on the optical fiber link, and thus affect the receiving sensitivity. Moreover, RIN is essentially a wideband noise, which reflects the influence of the light intensity fluctuation of the light source and the system on the electrical noise at the receiving end relative to the signal power.

[0003] When the system rate is higher, the link noise bandwidth is wider, the noise power is greater, and the signal-to-noise ratio is lower, the bit error rate is higher. Therefore, for high-speed optical modules, in order to ensure the reliability of the optical transmission system and the stability of the spectrum and power of the transmitting light source, it is necessary to design the nodes that are prone to cause reflection with high return loss to reduce the link reflection as much as possible.

[0004] In optical modules integrated with free-space circulators, the reflected light from the module side has the opportunity to return to the receiving end, which is equivalent to a part of the transmitting end signal light being directly shunted to the receiving end. This also has a very obvious effect on the performance degradation of high-speed optical devices, and this part of light is equivalent to optical crosstalk from the transmitting end to the receiving end. SUMMARY

[0005] The purpose of the present application is to provide an optical interface assembly and an optical module, which can effectively improve the return loss of the optical module and reduce the optical crosstalk from the transmitting end to the receiving end of the high-speed optical module.

[0006] In order to achieve one of the above purposes, the present application provides an optical interface assembly, comprising a lens barrel, a lens arranged in the lens barrel, an optical socket and a fiber ferrule arranged in the optical socket,

[0007] Further comprising a diaphragm between the lens and the fiber ferrule; the diaphragm has a light passing aperture smaller than the lens;

[0008] The first end face of the fiber ferrule opposite to the lens is arranged to be inclined to the axis of the fiber ferrule.

[0009] The light beam coupled into the fiber ferrule through the lens, the returned light reflected by the first end face is reflected out of the light passing aperture of the diaphragm.

[0010] As a further improvement of the embodiment, the light passing aperture of the diaphragm is conical or trumpet-like; the larger opening of the conical or trumpet-like light passing aperture faces the lens.

[0011] As a further improvement of the embodiment, the inner surface of the conical or trumpet-like light passing aperture is a blackened surface; the end face of the diaphragm facing the fiber ferrule is a blackened surface.

[0012] As a further improvement of the embodiment, the end face of the diaphragm facing the fiber ferrule is a conical surface or a convex spherical surface.

[0013] As a further improvement of the embodiment, the angle between the tangent of the conical surface or convex spherical surface and the cross section of the diaphragm is greater than or equal to 5°.

[0014] As a further improvement of the embodiment, the lens comprises a convex surface away from the fiber ferrule and a flat surface close to the fiber ferrule, the flat surface is arranged to be inclined to the cross section of the lens; the angle between the flat surface and the cross section of the lens is between 0° and 15°; and / or,

[0015] The angle between the first end face of the fiber ferrule and the cross section of the fiber ferrule is between 0° and 15°.

[0016] As a further improvement of the embodiment, the angle between the flat surface of the lens and the cross section of the lens is between 10° and 12°; and / or, the angle between the first end face and the cross section of the fiber ferrule is between 10° and 14°.

[0017] As a further improvement of the embodiment, the second end face of the fiber ferrule opposite to the lens is arranged to be inclined to the axis of the fiber ferrule, the inclination direction of the second end face is different from that of the first end face.

[0018] As a further improvement of the embodiment, the diaphragm and the lens barrel are integrated.

[0019] The application also provides an optical module comprising a housing, a light emitting end and a light receiving end arranged in the housing, and further comprising the optical interface assembly according to any one of the above embodiments.

[0020] The application adds the diaphragm design in the optical interface assembly to block the stray light returning to the inside of the optical device, effectively improves the return loss of the optical interface, reduces the optical crosstalk from the transmitting end to the receiving end of the high-speed optical module, and ensures the reliability of the optical transmission system and the stability of the spectrum and power of the transmitting light source. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Figure 1 is a cross-sectional view of an optical interface assembly according to an embodiment of the application;

[0022] Figure 2 Figure 2 is an exploded view of the optical interface assembly according to the embodiment of the application; Figure 1 Figure 3 is a side view of the optical interface assembly according to the embodiment of the application;

[0023] Figure 3 Figure 4 is a schematic diagram of the diaphragm effect in the optical interface assembly according to the embodiment of the application; Figure 2

[0024] Figure 4 Figure 5 is a schematic diagram of the diaphragm effect in the optical interface assembly according to the embodiment of the application;

[0025] Figure 5 Figure 6 is a schematic diagram of an optical interface assembly according to another embodiment of the application;

[0026] Figure 6 Figure 7 is an exploded view of the optical interface assembly according to the embodiment of the application; Figure 5

[0027] Figure 7 Figure 8 is a schematic diagram of an optical module according to another embodiment of the application. DETAILED DESCRIPTION

[0028] The application will be described in detail below with reference to the specific embodiments shown in the drawings. However, these embodiments do not limit the application, and the structural, method, or functional changes made by those of ordinary skill in the art based on these embodiments are also included in the protection scope of the application.

[0029] In each of the drawings of the application, the sizes of some structures or parts are exaggerated relative to those of other structures or parts, so as to facilitate the illustration of the basic structure of the subject matter of the application.

[0030] ​​Additionally, terms such as “above,” “over,” “below,” and “under,” used herein to indicate spatial relative position, are for illustrative purposes to describe the relationship of one unit or feature relative to another unit or feature as shown in the accompanying drawings. The terms of spatial relative position may be intended to include different orientations of the device in use or operation other than those shown in the figures. For example, if the device in the figures is flipped, a unit described as being “below” or “under” another unit or feature would be “above” that unit or feature. Therefore, the exemplary term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise) and the spatially related descriptive terms used herein shall be interpreted accordingly. When an element or layer is referred to as being “on” or “connected” to another component or layer, it may be directly on or connected to that other component or layer, or there may be intermediate elements or layers present.

[0031] Example 1

[0032] like Figures 1-4 As shown, the optical interface assembly 100 of this embodiment includes a lens 10 and an optical fiber ferrule 20. The lens 10 is disposed within a lens barrel 40. The optical fiber ferrule 20, together with a sleeve 50 and a tube 60, form an optical socket. The tube 60 is generally a metal tube, and the sleeve 50 is disposed within the sleeve 60, with the optical fiber ferrule 20 further disposed within the sleeve 50. An aperture 30 is also provided between the lens 10 and the optical fiber ferrule 20. The aperture of the aperture 30 is smaller than the aperture of the lens 10. In this embodiment, the aperture 30 and the lens barrel 40 are designed as an integral structure. In other embodiments, the aperture 30 and the lens barrel 40 can also be separate structures. Figure 3 and 4 As shown, the first end face 21 of the fiber optic ferrule 20, opposite the lens 10, is inclined relative to the axis of the fiber optic ferrule 20 (the axis being the straight line containing the optical axis of the fiber optic ferrule). A portion of the light beam coupled into the fiber optic ferrule 20 by the lens 10 is reflected back by the first end face 21 and is reflected outside the aperture of the stop 30, where it is blocked to prevent the return light from entering the optical components of the optical module. Considering the aperture of the stop 30 and lens parameters, the angle α between the first end face 21 and the cross-section of the fiber optic ferrule 20 can be selected within the range of 0° to 15°, commonly between 10° and 14°, such as 12° or 13°. In this embodiment, the fiber optic ferrule 20 is inclined relative to the second end face 22, which is farther from the lens 10, and the axis of the fiber optic ferrule 20, using a standard APC (Angled Physical Contact) end face. Figure 3As shown, the second end face 22 is inclined in a direction different from the first end face 21, the first end face 21 is inclined in the x direction, and the second end face 22 is inclined in the Z direction, which is equivalent to that the directions of the first end face 21 and the second end face 22 are rotated 90° with respect to each other. Of course, in other embodiments, the directions of the first end face 21 and the second end face 22 do not necessarily need to be rotated 90° with respect to each other, but can be other angles, as long as the first end face 21 and the second end face 22 are not parallel to each other.

[0033] The added light barrier of the optical interface assembly has a small light aperture, which can block the stray light such as end face reflection from returning to the optical device, effectively improving the return loss of the optical interface. When applied in an optical module, it can reduce the optical crosstalk from the transmitting end to the receiving end of the high-speed optical module, ensuring the reliability of the optical transmission system and the stability of the spectrum and power of the light source.

[0034] In this embodiment, as shown in Figure 1 The light aperture 31 of the light barrier 30 is conical or horn-shaped, and the larger opening of the conical or horn-shaped light aperture 31 faces the lens 10. This structure can minimize the light aperture of the light barrier 30 while not affecting the passage of the coupled light beam. The inner surface of the conical or horn-shaped light aperture 31 is blackened, and the end face 32 of the light barrier 30 facing the fiber ferrule 20 is also blackened, which can absorb the reflected stray light or reduce the reflection of stray light back into the optical device, further improving the return loss of the optical interface. Here, the blackened surface refers to roughening the surface or applying a light-absorbing coating, etc.

[0035] As shown in Figure 3 The above lens 10 is a plano-convex lens, which includes a convex surface 11 away from the fiber ferrule 20 and a flat surface 12 close to the fiber ferrule 20. The flat surface 12 is inclined with respect to the cross section of the lens 10, and the included angle b between the flat surface 12 and the cross section of the lens 10 is in the range of 0° to 15°, commonly between 10° and 12°, such as 11°, 12°, etc. Both the first end face 21 of the fiber ferrule 20 and the flat surface 12 of the lens 10 opposite to the first end face 21 are set as large-angle inclined surfaces, which can effectively reduce the reflected light.

[0036] Embodiment 2

[0037] As shown in Figure 5 and 6As shown, unlike Embodiment 1, in this embodiment, the end face 32 of the aperture 30 facing the fiber optic ferrule 20 does not require blackening treatment. Instead, this end face 32 is set as a conical or convex spherical surface. The conical or convex spherical surface is inclined towards the lens barrel 40 around the light-passing hole of the aperture 30. The angle c between the tangent of the conical or convex spherical surface and the cross-section of the aperture 30 is greater than or equal to 5°. The larger the angle C, the better; commonly, it is greater than or equal to 10°. Part of the return light reflected by the first end face 21 of the fiber optic ferrule 20 is reflected onto the conical or convex spherical surface of the aperture 30. Since the conical or convex spherical surface has a large inclination angle with the cross-section of the aperture, this part of the reflected light can be reflected out of the optical interface assembly, preventing the reflected light from entering the optical devices of the optical module. The aperture with this structure does not require blackening treatment on the aforementioned end face of the aperture, simplifying the aperture manufacturing process and saving costs.

[0038] Example 3

[0039] like Figure 7 As shown, the optical module of this embodiment includes a housing 200, an optical transmitter 300 and an optical receiver 400 disposed within the housing 200, and an optical interface assembly 100 coupled to the optical transmitter 300 and the optical receiver 400. Here, the optical interface assembly 100 is the optical interface assembly of any of the above embodiments.

[0040] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this application and are not intended to limit the scope of protection of this application. All equivalent implementation methods or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this application.

Claims

1. An optical module, comprising a housing, and an optical transmitter, an optical receiver, a lens, and an optical socket disposed within the housing, wherein the lens is located between the optical socket and the optical transmitter and the optical receiver for optical coupling between the optical socket and the optical transmitter and the optical receiver, characterized in that: The optical socket is provided with an optical fiber ferrule, and the first end face of the optical fiber ferrule opposite to the lens is inclined to the axis of the optical fiber ferrule. The lens is a plano-convex lens, including a convex surface away from the fiber optic ferrule and a flat surface close to the fiber optic ferrule. The flat surface is inclined to the cross-section of the lens. The axis of the fiber optic ferrule is parallel to the optical axis of the lens, and the axis of the fiber optic ferrule is deviated from the optical axis of the lens in a direction perpendicular to the axis, so that the light rays after being deflected by the flat surface of the lens are incident on the light-incident point of the first end face of the fiber optic ferrule.

2. The optical module according to claim 1, characterized in that: The optical module also includes an aperture, which is located between the lens and the fiber optic ferrule. A portion of the light beam coupled into the fiber optic ferrule through the lens is reflected back by the first end face and is reflected outside the aperture of the aperture.

3. The optical module according to claim 2, characterized in that: The aperture of the aperture has a larger opening and a smaller opening, the larger opening facing the lens and the smaller opening facing the fiber optic ferrule.

4. The optical module according to claim 3, characterized in that: The aperture of the aperture is conical or horn-shaped; the larger opening of the conical or horn-shaped aperture faces the lens.

5. The optical module according to claim 2, characterized in that: The end face of the aperture facing the fiber optic ferrule is a conical surface or a convex spherical surface.

6. The optical module according to claim 2, characterized in that: The lens is housed inside a lens barrel, and the aperture stop is an integral part of the lens barrel.

7. The optical module according to claim 1, characterized in that: The plane of the lens is tilted in a direction opposite to the direction of deviation from the axis of the optical fiber ferrule, and the first end face of the optical fiber ferrule is tilted in the same direction as the direction of deviation from the axis of the optical fiber ferrule.

8. The optical module according to claim 1, characterized in that: The optical fiber ferrule axis extends along the x-direction with the lens optical axis, and the optical fiber ferrule axis deviates from the lens optical axis in the y-direction.

9. The optical module according to claim 8, characterized in that: The first end face of the fiber ferrule is inclined from a vertical end face parallel to the y-direction to the x-direction, so that it faces the direction in which the fiber ferrule axis is deviated; the plane of the lens is inclined from a vertical end face parallel to the y-direction to the x-direction, so that it faces the opposite direction in which the fiber ferrule axis is deviated.

10. The optical module according to claim 1, characterized in that: The angle between the plane of the lens and the cross-section of the lens is between 0° and 15°.

11. The optical module according to claim 1, characterized in that: The angle between the first end face of the optical fiber ferrule and the cross-section of the optical fiber ferrule is between 10° and 15°.

12. The optical module according to claim 1, characterized in that: The second end face of the fiber optic ferrule, which is relatively far from the lens, is inclined to the axis of the fiber optic ferrule, and the inclination direction of the second end face is different from that of the first end face.

13. The optical module according to claim 1, characterized in that: The optical module also includes a circulator.

14. An optical module, comprising a housing, and an optical transmitter, an optical receiver, a lens, and an optical socket disposed within the housing, wherein the lens is located between the optical socket and the optical transmitter and the optical receiver for optical coupling between the optical socket and the optical transmitter and the optical receiver, and the optical socket contains an optical fiber ferrule; characterized in that: It also includes an aperture disposed between the lens and the fiber optic ferrule, wherein the aperture of the aperture has a larger opening and a smaller opening, the larger opening facing the lens and the smaller opening facing the fiber optic ferrule; The first end face of the fiber optic ferrule opposite to the lens is inclined to the axis of the fiber optic ferrule. The light beam coupled into the fiber ferrule through the lens, part of which is reflected back by the first end face, is reflected outside the aperture of the aperture. The lens includes a convex surface relatively far from the fiber optic ferrule and a flat surface relatively close to the fiber optic ferrule. The flat surface is inclined relative to the cross-section of the lens. The axis of the fiber optic ferrule is parallel to the optical axis of the lens, and the axis of the fiber optic ferrule is deviated from the optical axis of the lens in a direction perpendicular to the axis, so that the light rays deflected by the flat surface of the lens are incident on the light-incident point of the first end face of the fiber optic ferrule.

15. The optical module according to claim 14, characterized in that: The angle between the plane of the lens and the cross-section of the lens is between 0° and 15°.

16. The optical module according to claim 14, characterized in that: The end face of the aperture facing the fiber optic ferrule is a conical surface or a convex spherical surface.

17. The optical module according to claim 16, characterized in that: The angle between the tangent of the conical or convex spherical surface and the cross-section of the aperture is greater than or equal to 5°.

18. The optical module according to claim 14, characterized in that: The angle between the first end face of the optical fiber ferrule and the cross-section of the optical fiber ferrule is between 0° and 15°.

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