CN111290087A

CN111290087A - Light splitting detector

Info

Publication number: CN111290087A
Application number: CN202010235961.6A
Authority: CN
Inventors: 罗腾; 洪小鹏; 范杰乔; 肖清明
Original assignee: Accelink Technologies Co Ltd; Wuhan Optical Valley Information Optoelectronic Innovation Center Co Ltd
Current assignee: Accelink Technologies Co Ltd; Wuhan Optical Valley Information Optoelectronic Innovation Center Co Ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-06-16
Also published as: WO2021196747A1

Abstract

The embodiment of the application provides a spectral detector, including input/output portion, spectral lens, detector chip and tube sealing. The input/output unit includes an input terminal and an output terminal. The input end is used for inputting a light beam. The beam splitting lens is used for splitting an input light beam from an input end into a transmitted light beam and a reflected light beam. The output end is used for outputting a reflected light beam. The detector chip is used for converting the transmitted light beam into an electrical signal. And a passivation film is arranged on the surface of the detector chip. The input and output part, the spectral lens and the detector chip are packaged in the sealing tube through non-air tightness. The input and output part, the spectral lens and the detector chip are packaged in the sealing tube through non-air tightness, namely, the detector chip is not protected by a sealing cap, so that the outer diameter of the spectral detector can be reduced, and the miniaturized modular use of the spectral detector is facilitated. The passive film prevents the detector chip from being influenced by water vapor, ion charges and the like, so that the detector chip can obtain higher reliability and waterproof performance.

Description

Light splitting detector

Technical Field

The application relates to the technical field of optical communication, in particular to a light splitting detector.

Background

The spectral detector is one of optical power detectors, obtains optical signal information of the whole optical transmission line by detecting a micro optical signal split from the optical transmission line, and is widely applied to an optical fiber communication system to perform online monitoring on the power of the optical signal, so that the power monitoring and management of the optical signal are realized. The existing spectral detector has larger outer diameter and is not beneficial to the use of a miniaturized module.

Disclosure of Invention

In view of the above, embodiments of the present application are expected to provide a spectroscopic detector having a smaller outer diameter. In order to achieve the above beneficial effects, the technical solution of the embodiment of the present application is implemented as follows:

the embodiment of the application provides a spectral detector, includes:

an input and output section including an input end and an output end, the input end being used for inputting a light beam;

a beam splitting lens for splitting an input beam from the input end into a transmitted beam and a reflected beam, the output end for outputting the reflected beam;

the detector chip is used for converting the transmitted light beams into electric signals, and a passivation film is arranged on the surface of the detector chip; and

and the input and output part, the spectral lens and the detector chip are packaged in the sealing tube through non-airtightness.

Furthermore, the beam splitting lens comprises a collimating lens and a beam splitting film arranged on a light emergent surface of the collimating lens, the input/output part is bonded with a light incident surface of the collimating lens, the detector chip is positioned on one side of the collimating lens, which is far away from the input/output part, the collimating lens is used for collimating the input beam at the input end, and the input beam at the input end is divided into the transmission beam and the reflection beam through the beam splitting film.

Further, the collimating lens is a GRIN lens.

Further, the spectral detector includes a focusing lens located between the collimating lens and the detector chip, the focusing lens being configured to converge the transmitted light beam onto the detector chip.

Furthermore, the focusing lens is a spherical lens, and the distance between the spherical lens and the detector chip is L, wherein L is larger than or equal to 1mm and smaller than or equal to 2 mm.

Further, the spectral detector includes:

and the wedge angle prism is bonded with the light-emitting surface of the collimating lens and is used for deviating the light beam from the output end from the detector chip and deviating the transmitted light beam to the detector chip.

Furthermore, the wedge angle prism comprises a flat end face and a wedge face opposite to the flat end face, the light emitting face of the collimating lens is bonded with the flat end face, the light beam emitted from the wedge face and coming from the output end deviates from the detector chip, and the transmitted light beam emitted from the wedge face deviates from the detector chip.

Further, an included angle between the wedge surface and the flat end surface is α, wherein α is more than or equal to 7 degrees and less than or equal to 9 degrees;

and/or the incident light beam at the input end is emitted from the bottom line of the wedge surface, and the reflected light beam at the output end is emitted from the top line of the wedge surface;

and/or the flat end face is provided with an antireflection film.

Furthermore, an included angle between the light incident surface of the light splitting lens and the optical axis of the light splitting lens is β, wherein β is more than or equal to 7 degrees and less than or equal to 9 degrees;

and/or the photosensitive surface of the detector chip is larger than or equal to a light spot formed by the transmitted light beam;

and/or the sealing pipe adopts waterproof glue for non-airtight packaging;

and/or the input and output part is a double-core pin.

The spectral detector that this application embodiment provided, input/output portion, spectral lens and detector chip pass through non-gas tightness encapsulation in the envelope, that is to say, the detector chip does not seal the cap protection, does not exist in the envelope and is used for holding inert gas's cavity structure, so, can reduce spectral detector's external diameter, do benefit to the miniaturized modularization of spectral detector and use. The passive film prevents the detector chip from being influenced by water vapor, ion charges and the like, so that the detector chip can obtain higher reliability and waterproof performance. The sealing pipe can prevent external stray light from influencing internal light intensity detection, and can protect an optical structure in the sealing pipe from being damaged. In addition, the non-airtight packaging process is simple in flow, low in cost and high in reliability, and is more beneficial to integration of a miniaturized device and a module.

Drawings

Fig. 1 is a schematic structural diagram of a spectroscopic detector provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of the optical path of the photodetector of FIG. 1;

FIG. 3 is an enlarged view taken at H in FIG. 1;

fig. 4 is an enlarged view at D in fig. 1.

Description of the reference numerals

A spectroscopic detector 100; an input/output unit (10); an input terminal 11; an output end 12; a spectroscopic lens 20; a collimator lens 21; a light-emitting surface 21 a; a light incident surface 21 b; a detector chip 30; a pipe sealing 40; a focusing lens 50; a wedge angle prism 60; a flat end surface 60 a; a wedge surface 60 b.

Detailed Description

It should be noted that, in the present application, technical features in examples and embodiments may be combined with each other without conflict, and the detailed description in the specific embodiment should be understood as an explanation of the gist of the present application and should not be construed as an improper limitation to the present application. Wherein mm is international unit millimeter. The present application will now be described in further detail with reference to the accompanying drawings and specific examples.

Referring to fig. 1 and fig. 2, a spectroscopic detector 100 according to an embodiment of the present disclosure includes an input/output portion 10, a spectroscopic lens 20, a detector chip 30, and a sealing tube 40. The input/output section 10 includes an input terminal 11 and an output terminal 12. The input end 11 is for an input light beam a. The beam splitting lens 20 is used to split an input light beam a from the input end 11 into a transmitted light beam B and a reflected light beam C. The output end 12 is used for outputting a reflected light beam C. The detector chip 30 is used to convert the transmitted beam B into an electrical signal. The surface of the detector chip 30 is provided with a passivation film. The input/output portion 10, the spectroscopic lens 20, and the detector chip 30 are hermetically sealed in the sealing tube 40.

The part of the input light beam a of the input end 11 is reflected by the beam splitting lens 20 to become a reflected light beam C to the output end 12 for continuous transmission, so as to realize light beam output, the other part of the input light beam a of the input end 11 is refracted by the beam splitting lens 20 to become a transmitted light beam B to the detector chip 30, and the transmitted light beam B is converted into an electrical signal by the detector chip 30, so that the optical signal information of the whole optical transmission route is obtained, and the monitoring of the whole optical transmission route is realized. The input/output part 10, the spectroscopic lens 20 and the detector chip 30 are packaged in the sealing tube 40 through non-air tightness, that is, the detector chip 30 is not protected by a sealing cap, and a cavity structure for accommodating inert gas does not exist in the sealing tube 40, so that the outer diameter of the spectroscopic detector 100 can be reduced, and the spectroscopic detector is beneficial to being used in a miniaturized module, so as to be used in optoelectronic modules such as a coherent network, an Erbium Doped Fiber Amplifier (EDFA), an Optical Switch (OSW), and the like. The passivation film prevents the detector chip 30 from being affected by moisture, ion charges, etc., so that the detector chip 30 obtains higher reliability and waterproof performance. The sealing tube 40 can not only prevent external stray light from affecting the internal light intensity detection, but also protect the optical structure in the sealing tube 40 from being damaged. In addition, the non-airtight packaging process is simple in flow, low in cost and high in reliability, and is more beneficial to integration of a miniaturized device and a module.

Further, the passivation film includes, but is not limited to, an oxide, a nitride, or a synthetic resin, etc. Oxides include, but are not limited to, silica, alumina, or titania, and the like. Nitrides include, but are not limited to, silicon nitride, boron nitride, or gallium nitride, among others. The synthetic resin includes, but is not limited to, polyimides or polysiloxanes, etc.

In an embodiment, referring to fig. 1 and fig. 2, the spectroscopic lens 20 includes a collimating lens 21 and a spectroscopic film (not shown) disposed on the light-emitting surface 21a of the collimating lens 21. The input/output unit 10 is bonded to the light incident surface 21b of the collimator lens 21. The detector chip 30 is located on the side of the collimator lens 21 remote from the input-output section 10. The collimating lens 21 is used to collimate the input light beam a at the input end 11. The input light beam a at the input end 11 is split into a transmitted light beam B and a reflected light beam C by the splitting film.

It is understood that the light incident surface 21b of the collimator lens 21 refers to an end surface of the input light beam a of the input end 11 entering the collimator lens 21. The light exit surface 21a of the collimator lens 21 is an end surface through which the transmitted light beam B exits the collimator lens 21.

The splitting film has a certain transmittance and reflectance, the input light beam a of the input end 11 is collimated by the collimating lens 21 to become a parallel light beam, a part of the input light beam a of the input end 11 is reflected by the splitting film to become a reflected light beam C to the output end 12, and another part of the input light beam of the input end 11 is refracted by the splitting film to become a transmitted light beam B to the detector chip 30. The light incident surface 21b of the collimating lens 21 is bonded with the input and output part 10 to fix the collimating lens 21, so that the coupling efficiency can be improved, and the collimating lens 21 and the input and output part 10 are prevented from being fixedly installed by using a glass tube, so that the installation process is simplified, the diameter of the light splitting detector 100 is further reduced, and the whole optical structure is compact and the whole length is small.

Further, the light splitting film can be set to different light splitting ratios, so that the detector chip 30 can obtain corresponding different responsivities, for example, the light splitting ratio of the light splitting film is between 1% and 10%. The input/output unit 10 and the light incident surface 21b of the collimator lens 21 may be bonded by ultraviolet adhesive.

In some embodiments, the seal tube 40 is a metal tube. Therefore, the influence of external stray light on the internal light intensity detection is further avoided. In other embodiments, the sealing tube 40 may also be a ceramic tube.

In one embodiment, referring to fig. 1 and 2, the collimating lens 21 is a GRIN lens. The GRIN lens, i.e., the gradient index lens, has a small volume, which is advantageous for further reducing the size of the spectral detector 100.

In one embodiment, referring to fig. 1 and 2, the spectroscopic probe 100 includes a focusing lens 50. The focusing lens 50 is located between the collimator lens 21 and the detector chip 30. The focusing lens 50 is used to focus the transmitted beam B onto the detector chip 30.

After the input light beam a at the input end 11 is collimated by the collimating lens 21, a part of the input light beam a at the input end 11 is reflected by the splitting film to be a reflected light beam C to the output end 12, another part of the input light beam at the input end 11 is refracted by the splitting film to be a transmitted light beam B to the focusing lens 50, and the focusing lens 50 converges the transmitted light beam B to the detector chip 30. The collimated transmitted light beam B is focused by the focusing lens 50 and projected onto the detector chip 30, so that the area of the photosensitive surface of the detector chip 30 can be reduced, which is beneficial to reducing the size of the detector chip 30, and further reducing the size of the spectroscopic detector 100.

In one embodiment, referring to fig. 1 and 2, the focusing lens 50 is a spherical lens. The distance between the spherical lens and the detector chip 30 is L, wherein L is more than or equal to 1mm and less than or equal to 2 mm. Illustratively, L may be 1mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm, 1.9mm, 2mm, and the like. In this manner, the spherical lens is facilitated to converge the transmitted beam B onto the detector chip 30.

In one embodiment, referring to fig. 1 and 2, a glass tube (not shown) is disposed outside the spherical lens, and the glass tube is bonded to the sealing tube 40. Thus, the spherical lens is convenient to fix.

In one embodiment, referring to fig. 1 and 2, the spectroscopic probe 100 includes a wedge angle prism 60. The wedge-angle prism 60 is bonded to the light exit surface 21a of the collimator lens 21. The wedge angle prism 60 is used to deflect the beam from the output end 12 away from the detector chip 30 and to deflect the transmitted beam B toward the detector chip 30.

Since the optical path is reversible, the reflected light beam C may be reflected back to the collimating lens 21 and then emitted from the light emitting surface of the collimating lens 21 to the detector chip 30 after entering the output end 12, and thus the detector chip 30 is affected by the reflected light beam C, which results in an error in monitoring the optical signal information of the whole optical transmission path. In the embodiment of the present application, the wedge angle prism 60 is used to deviate the light beam from the output end 12 from the detector chip 30, that is, the wedge angle prism 60 is used to deviate the light beam from the output end 12 again, so that the light beam from the output end 12 cannot be projected to the detector chip 30, and meanwhile, the transmitted light beam B is deviated to the detector chip 30, thereby avoiding a monitoring error and obtaining a high directivity. The wedge-angle prism 60 is fixed by adhering the wedge-angle prism 60 to the light-emitting surface of the collimating lens 21, so that the size of the spectral detector 100 is reduced while high directivity is obtained, and the overall optical structure of the spectral detector 100 is further compact, and the overall diameter and length are small.

In some embodiments, referring to fig. 1 and 2, the collimating lens 21 is a GRIN lens, and since the end surface of the GRIN lens may be flat, the wedge angle prism 60 may be attached to the end surface of the GRIN lens.

In one embodiment, referring to fig. 1, 2 and 3, the wedge prism 60 includes a flat end surface 60a and a wedge surface 60b opposite to the flat end surface 60 a. The light emitting surface 21a of the collimator lens 21 is bonded to the flat end surface 60 a. That is, the wedge prism 60 is a right-angle wedge prism. The light beam from the output end 12 exiting the wedge surface 60b is deflected away from the detector chip 30. The transmitted beam B exiting the wedge surface 60B is deflected toward the detector chip 30.

In one embodiment, referring to FIGS. 1, 2 and 3, the wedge surface 60B is at an angle α with respect to the planar end surface 60a, wherein 7 ° ≦ α ≦ 9 °, that is, the wedge angle of the wedge angle prism 60 is α, wherein 7 ° ≦ α ≦ 9 °, exemplary α is 7 °, 7.5 °, 8 °, 8.5 °, or 9 °, etc. thus, the light beam from the output end 12 exiting the wedge surface 60B can be better deflected away from the detector chip 30, and the transmitted light beam B exiting the wedge surface 60B is deflected toward the detector chip 30, further increasing directivity.

In one embodiment, referring to fig. 1, 2 and 3, the incident light beam at the input end 12 exits from the bottom line F of the wedge surface 60b, and the reflected light beam at the output end 11 exits from the top line G of the wedge surface 60 a. In this way, the light beam from the output end 12 emitted from the wedge surface 60B can be more favorably deflected from the detector chip 30, and the transmitted light beam B emitted from the wedge surface 60B can be deflected toward the detector chip 30, thereby further improving directivity.

Note that the thick end of the wedge prism 60 is the bottom end, the thin end of the wedge prism 60 is the top end, and the intersection line of the wedge surface 60b and the bottom end surface of the wedge prism 60 is the bottom line F. The intersection line of the wedge surface 60b and the tip end surface of the wedge prism 60 is a tip line G. The wedge angle prism 60 is a right angle wedge angle prism, and the included angle between the flat end surface 60a and the bottom end surface of the wedge angle prism 60 is 90 degrees.

It will be appreciated that the incident beam at the input end 12 exits from the bottom line F of the wedge surface 60b and the reflected beam at the output end 11 exits from the top line G of the wedge surface 60 a. The bottom end surface of the wedge prism 60 is in the same plane as the bottom surface of the collimator lens 21, and the top end surface of the wedge prism 60 is in the same plane as the top surface of the collimator lens 21.

In one embodiment, referring to fig. 1 and 2, the flat end surface 60a is provided with an antireflection film. Since the flat end surface 60a is the light incident surface of the wedge prism 60, the antireflection film is used to reduce or eliminate the reflectivity of the flat end surface 60a and increase the light transmittance of the light incident surface of the wedge prism 60.

In one embodiment, referring to fig. 1, fig. 2 and fig. 4, the angle between the incident surface of the splitting lens 20 and the optical axis E of the splitting lens 20 is β, wherein 7 ° ≦ β ≦ 9 °, for example, β is 7 °, 7.5 °, 8 °, 8.5 ° or 9 °, and so on.

It can be understood that the splitting lens 20 includes a collimating lens 21 and a splitting film disposed on the light emitting surface 21a of the collimating lens 21, an included angle between the light incident surface 21b of the collimating lens 21 and the optical axis E of the collimating lens 21 is β, wherein an angle is equal to or greater than 7 degrees and equal to or less than β degrees and equal to or less than 9 degrees.

In one embodiment, referring to fig. 1 and 2, the photosensitive surface of the detector chip 30 is greater than or equal to the spot formed by the transmitted beam B. Therefore, the transmitted beams B can be emitted to the photosensitive surface of the detector chip 30, and the accuracy is improved.

In one embodiment, referring to fig. 1 and 2, the sealing tube 40 is non-hermetically sealed with a waterproof adhesive. The waterproof glue prevents the glue from absorbing water to cause the deformation of the sealing tube 40, thereby preventing the change of the structural positions among the input/output part 10, the spectroscopic lens 20 and the detector chip 30 to cause the change of the optical path in the spectroscopic detector 100. Therefore, the waterproof glue is adopted for non-airtight packaging, so that stronger waterproof performance and better reliability can be obtained.

Specifically, the waterproof glue includes, but is not limited to, silicone-based encapsulation glue and the like.

In one embodiment, referring to fig. 1 and 2, the input/output portion 10 is a dual-core pin. Specifically, the two-core pin includes a two-core capillary and a sleeve located outside the two-core capillary, the input end 11 and the output end 12 are located inside the two-core capillary, and the sleeve is connected to the sealing tube 40. The two-core pin facilitates bonding with the beam splitting lens 20.

Preferably, the input end 11 may be a single mode optical fiber. The output end 12 may be a single mode optical fibre.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A spectroscopic detector, comprising:

2. The spectrometer according to claim 1, wherein the beam splitting lens includes a collimating lens and a beam splitting film disposed on a light emitting surface of the collimating lens, the input/output portion is bonded to the light incident surface of the collimating lens, the detector chip is disposed on a side of the collimating lens away from the input/output portion, the collimating lens is configured to collimate the input light beam at the input end, and the input light beam at the input end is split into the transmitted light beam and the reflected light beam by the beam splitting film.

3. The light splitting detector of claim 2, wherein the collimating lens is a GRIN lens.

4. The spectroscopic detector of claim 2, wherein the spectroscopic detector comprises a focusing lens positioned between the collimating lens and the detector chip, the focusing lens configured to focus the transmitted beam onto the detector chip.

5. The spectroscopic detector of claim 4, wherein the focusing lens is a spherical lens, and the distance between the spherical lens and the detector chip is L, wherein L is greater than or equal to 1mm and less than or equal to 2 mm.

6. The spectroscopic detector of claim 2, wherein the spectroscopic detector comprises:

7. The spectroscopic detector of claim 6, wherein the wedge-angle prism comprises a flat end surface and a wedge surface opposite to the flat end surface, the light exit surface of the collimating lens is bonded to the flat end surface, the light beam emitted from the output end and emitted from the wedge surface is deflected from the detector chip, and the transmitted light beam emitted from the wedge surface is deflected from the detector chip.

8. The spectroscopic detector of claim 7 wherein the wedge surface is at an angle α with 7 ° - α ° -9 °;

and/or the flat end face is provided with an antireflection film.

9. The photodetector of any one of claims 1 to 8, wherein an included angle between the light incident surface of the light splitting lens and an optical axis of the light splitting lens is β, wherein 7 ° or more and β or less and 9 ° or less;

and/or the sealing pipe adopts waterproof glue for non-airtight packaging;

and/or the input and output part is a double-core pin.