CN110967794B

CN110967794B - Multi-beam combining assembly, light emitting assembly and light module

Info

Publication number: CN110967794B
Application number: CN201911146169.7A
Authority: CN
Inventors: 黄钊; 肖潇; 李振东
Original assignee: SHENZHEN GIGALIGHT TECHNOLOGY CO LTD
Current assignee: SHENZHEN GIGALIGHT TECHNOLOGY CO LTD
Priority date: 2019-11-21
Filing date: 2019-11-21
Publication date: 2021-10-29
Anticipated expiration: 2039-11-21
Also published as: CN110967794A

Abstract

The invention relates to a multi-beam combining assembly, an emitting light assembly and an optical module. The multi-beam combination assembly comprises two reflectors, wherein openings of the two reflectors are oppositely arranged, the projections of the two reflectors on a first set plane are not overlapped, the projections of the two reflectors on a second set plane are parabolas, and the optical axes and the focuses of the two parabolas are overlapped; the two reflectors are obtained by respectively moving the projections on the second set plane by a preset distance along the direction vertical to the second set plane; the first setting plane and the second setting plane are perpendicular to each other; wherein, the two reflectors are respectively marked as a first reflector and a second reflector; and multiple beams of signal light incident along the optical axis are converged at the focus after being reflected by the first reflector, the converged signal light is coupled into a beam of emergent light after being reflected by the second reflector, and the emergent light is parallel to the optical axis. The multi-beam combining function can be realized through a simple structure.

Description

Multi-beam combining assembly, light emitting assembly and light module

Technical Field

The invention relates to the technical field of photoelectric communication, in particular to a multi-beam combining assembly, an emitting optical assembly and an optical module.

Background

The demand of the industry for high bandwidth, high capacity optical communication devices is also becoming more stringent against the large background of the large growth of global data traffic. The demand for improving the data transmission rate of the optical module, which is a key part of the optical communication device, is also more and more urgent.

The optical module generally includes two parts, namely a Transmitter Optical Subassembly (TOSA) and a Receiver Optical Subassembly (ROSA), wherein the internal part of the TOSA is formed by a semiconductor laser and used for transmitting a modulated optical signal; the latter is internally formed by a photodetector for receiving the modulated optical signal. Due to the continuous increase in communication rate and the limitation of single channel rate of semiconductor laser chips, TOSAs that satisfy MSA (multi-source agreement) protocols typically have two or more lasers built into them to form multiple channels. Therefore, inside the TOSA, an optical module is required to combine the signal light emitted by the multiple lasers, and then the signal light is transmitted to a fiber adapter to be coupled into a single-mode fiber.

The existing light beam combining device comprises a thin film filter and a polarization beam combiner, wherein the thin film filter has high requirements on a coating process and a bonding process, and the phenomenon that the beam combining fails if the film filter is not well mastered or the light intensity of some signals in the light beam after the beam combining is finished is small is caused; the use of a polarization beam combiner is also high in the requirements and cost of the manufacturing process.

Disclosure of Invention

In view of the above, it is desirable to provide a multi-beam combining module, an emitting optical module and an optical module.

A multi-beam combination assembly is used for coupling multiple incident signal beams into an emergent beam and comprises two reflectors, wherein openings of the two reflectors are oppositely arranged, and the projections of the two reflectors on a first set plane are not overlapped; the projections of the two reflectors on the second set plane are parabolas, the optical axes and the focuses of the two parabolas are coincident, and the two reflectors are obtained by respectively moving the projections on the second set plane by a preset distance along the direction vertical to the second set plane; the first setting plane and the second setting plane are perpendicular to each other;

wherein, the two reflectors are respectively marked as a first reflector and a second reflector; multiple beams of signal light incident along the optical axis are reflected by the first reflector and then converged at the focus, the converged signal light is reflected by the second reflector and then coupled into a beam of emergent light, and the emergent light is parallel to the optical axis

In one embodiment, the plurality of signal lights are incident on the first reflecting mirror at the same horizontal plane.

In one embodiment, a projection of the first reflector on the second setting plane is denoted as a first parabola, and the first parabola is: y is²＝32X。

In one embodiment, the second mirror is located at the second mirrorThe projection of the two setting planes is marked as a second parabola, and the second parabola is: y is²＝4X。

In one embodiment, the first mirror and the second mirror are packaged as a unitary structure, and the transmission medium inside the unitary structure comprises air or vacuum.

In one embodiment, the first reflector and the second reflector are formed in one step in a mold opening mode.

In one embodiment, the diameter of the outgoing light is less than 0.4 mm.

Based on the same inventive concept, the present application further provides a light emitting assembly comprising the aforementioned multi-beam combining assembly.

In one embodiment, the light emitting assembly further comprises a laser module and a collimation module;

multiple signal lights radiated by the laser module are collimated by the collimation module and then are incident to the multi-beam combination assembly, and the multiple signal lights are coupled into a signal light by the multi-beam combination assembly and then are emitted from a light emitting area of the multi-beam combination assembly.

In one embodiment, the laser module includes any one of a two-channel type laser module, a four-channel type laser module, or an eight-channel type laser module.

In one embodiment, the light emitting assembly comprises a circular light emitting assembly or a square light emitting assembly.

In one embodiment, the focal length of the first mirror in the multi-beam combining assembly is denoted as f₁The focal length of the second reflector is denoted as f₂，f₁、f₂Satisfies the formula:

wherein d is₁Denotes a first distance, d₂Represents a second distance; the first distance represents a plurality of incident signal lights of the multi-beam combining assembly projected on a second set planeThe distance between one beam of signal light farthest from the optical axis and the optical axis; the second distance represents a distance between the beam of signal light reflected and collimated by the second reflector and the optical axis under the projection of the multi-beam combining assembly on the second set plane.

In one embodiment, the emitting light assembly is a square emitting light assembly, and the first distance d₁A second distance d₂Focal length f of the first reflector₁Focal length f of the second mirror₂The following constraints are satisfied:

d₂<R

f₁+f₂<L₁

wherein R is the light transmission radius of the light emitting region, L₁Removing the remaining length, L, of the laser module and the collimating module for the length in the housing of the square emitting optical assembly₂The inner width of the housing of the square emitting light assembly.

Based on the same inventive concept, the application also provides an optical module, which comprises a TOSA module and a ROSA module;

wherein, the TOSA module is the aforementioned light emitting component.

The multi-beam combining assembly, the light emitting assembly and the optical module are obtained by arranging the two reflectors in a mode that the openings are opposite and the projections of the two reflectors on the first set plane are not overlapped, the projections of the two reflectors on the second set plane are parabolas, the optical axes and the focuses of the two parabolas are overlapped, and in addition, the two reflectors respectively move the projections on the second set plane by preset distances along the direction vertical to the second set plane; make the multi-beam of this application close and restraint subassembly can be in after being reflected along the multi-beam signal light that is on a parallel with the optical axis incident one of them speculum focus department convergence, the signal light beam after the convergence couples into a bundle of emergent light through another speculum reflection back, and this emergent light is on a parallel with the optical axis to can realize multi-beam through simple structure and close the bundle function, in addition, because the multi-beam of this application closes and restraints the subassembly and does not relate to bonding process and simple manufacture in the transmission of light beam, so can avoid because the bonding process brings close bundle failure or close the light intensity of certain several signals in the light beam after the bundle is accomplished scheduling problem slightly.

Drawings

FIG. 1 is a top view of a multi-beam combining assembly in one embodiment;

FIG. 2 is a top view of an embodiment of an emissive light assembly;

FIG. 3 is a side view of an optical path in a simulation of the multi-beam combining assembly of FIG. 1;

FIG. 4 is a diagram of simulation results when the multi-beam combining assembly of FIG. 1 is simulated;

FIG. 5 is a schematic diagram of a thin film filter in an exemplary technique for multiple beam combining;

fig. 6 is a schematic structural diagram of a polarization beam combiner in an exemplary technique for combining multiple light beams.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

Currently, a multi-beam combining optical assembly commonly used in TOSA devices is a Thin Film Filter (TFF) or a plurality of Polarization Beam Combiners (PBC) to combine beams, and the thin film filter TFF is a narrow band filter that uses four different wavelengths to combine four beams of signal light. The polarization beam combiner PBC has a characteristic of combining two beams having two orthogonal polarization directions into one, and thus can combine a plurality of beams by combining a plurality of polarization beam combiners.

Fig. 5 is a schematic structural diagram of a thin film filter in an exemplary technique for combining multiple light beams. LD-1, LD-2, LD-3 and LD-4 respectively represent four different lasers, and the lasers LD-1, LD-2, LD-3 and LD-4 respectively emit signal lights with the wavelengths of lambda 1, lambda 2, lambda 3 and lambda 4 after being modulated, and the signal lights are transmitted to the inlets of the thin film filters F1, F2, F3 and F4 after being collimated by four collimating lenses. The thin film filters F1, F2, F3 and F4 are narrow band filters corresponding to the central wavelengths λ 1, λ 2, λ 3 and λ 4, respectively, and the coatings for filtering are coated on their contact surfaces with the Block, respectively, and they can transmit a light beam having a wavelength within the pass band and reflect a light beam having a wavelength outside the pass band. Taking the signal light with the wavelength λ 1 as an example, the thin-film filter F1 has the wavelength λ 1 at the center wavelength in the passband, and therefore the signal light can pass through the F1 filter with high transmittance and reach the inside of Block. The other end face of Block is coated with HR (high reflection) film, so that the signal light with wavelength λ 1 is reflected at this end face and reaches the filter F2. Since the wavelength λ 1 is outside the pass band of the narrow band filter F2, the signal light is reflected back at the filter F2 and continues to propagate inside the Block, instead of being transmitted outside the Block through the filter F2. By analogy, the wavelength λ 1 is also out of the channels of the narrow band filters F3 and F4, so that the signal light of the wavelength continues to be reflected at the two filters F3 and F4, and finally exits at the area where the Block end face is coated with an AR (anti-reflection) film. Based on the same principle, the signal lights with the wavelengths λ 2, λ 3 and λ 4 will have similar propagation modes in the narrow-band filters and the Block, so that the four signal lights with the wavelengths λ 1, λ 2, λ 3 and λ 4 will be combined and output at the outlet of the Block.

It can be seen that the TFF mainly uses four signal beams to transmit and reflect at the end faces of four narrow-band filters, so as to realize four-in-one of the four beams, and these narrow-band filters are usually adhered to specific positions of the Block end faces by glue. Therefore, the beam combining performance of the TFF is directly determined by the performance of the filter coating and the adhesion process level of the narrow band filter. However, the TFF has several difficulties in the manufacturing process:

1. has higher requirement on the coating process. The filter film on the end face of the narrow band filter determines whether the signal beam is reflected or transmitted at this interface. The central wavelengths of four thin-film filters TFF working in CWDM wave band are 1271nm, 1291nm, 1311nm and 1331nm respectively, and the channel bandwidth is +/-6.5 nm; the central wavelengths of four narrow-band filters of the thin-film filter working in the LAN-WDM wave band are 1295.56nm, 1300.05nm, 1304.58nm and 1309.14nm respectively, and the channel bandwidth is +/-1.03 nm. Therefore, the film system of the filtering coating needs to be precisely adjusted and optimized to match corresponding wavelength and bandwidth, and particularly, the narrow-band filter working in LAN-WDM has smaller central wavelength interval and bandwidth, so that the requirement on the coating process level is higher.

And 2, a manufacturing process and a coating process of the Block. The material of Block is typically K9 optical glass, and care is needed at any time during the process of machining to the required dimensions to prevent cracking and chipping. In addition, the parallelism of the two end surfaces needs to be accurately controlled to ensure the correct transmission of the light beam in the light source. And an HR film and an AR film are correspondingly plated on a specific area on one side of the emergent end face of the Block, so that the requirement on a plating process is high.

3. And (5) bonding glue. Since the four narrow-band filters and the Block are made of K9 optical glass, the glue for bonding the four narrow-band filters and the Block needs to have optical characteristics close to those of K9 glass, such as refractive index, abbe number, thermal expansion coefficient and the like, so as to keep the consistency of the signal light beam in the propagation process as much as possible.

4. The bonding requirement of the narrow-band filter is high. In the process of bonding the narrow-band filter to the Block, a clamp and a coupling adjusting table with extremely high precision need to be designed and built, so that the end faces of the narrow-band filter and the Block are kept horizontal as much as possible. If the parallelism between the narrow-band filter and the end face of the Block is not high in the finished product, the phenomenon that the beam combination fails due to the fact that the propagation paths of the four beams of signal light are not overlapped or the light intensity of some signals in the beams after the beam combination is finished is small may occur.

Fig. 6 is a schematic structural diagram of a polarization beam combiner for combining multiple light beams according to an exemplary technique. LD-1, LD-2, LD-3 and LD-4 respectively represent four-way lasers, the polarization directions of laser beams lambda 1, lambda 2, lambda 3 and lambda 4 emitted by the four-way lasers LD-1, LD-2, LD-3 and LD-4 are consistent, and the laser beams are collimated by a collimating lens and then transmitted to corresponding polarization beam combiners PBC-1 and PBC-2. After the laser beam lambda 1 passes through the half-wave plate, the polarization direction of the laser beam lambda 1 is changed by 90 degrees, so that the polarization direction of the laser beam lambda 1 is perpendicular to the polarization direction of the laser beam lambda 2, and the two beams of light are finally combined under the action of PBC-1. Similarly, the laser beam λ 3 and the laser beam λ 4 are combined in the same process. Finally, the four laser beams λ 1, λ 2, λ 3, and λ 4 are finally combined into one beam by the polarization beam combiner PBC-3 after passing through the isolator.

The beam combination method based on the polarization of the laser beam has the following difficulties:

PBC manufacturing process is high in requirement and cost. The PBC is manufactured by adhering two triangular crystals to two ends of a middle parallelogram crystal through glue to form a rectangular crystal. First, when a parallelogram crystal or a triangle crystal is processed, defects such as edge chipping are likely to occur due to a small size. In addition, the processing difficulty of processing two 45-degree end faces of the parallelogram crystal is high, and the control on the angle and the parallelism of the two end faces is mainly reflected. In addition, HR film and a special film system for polarization beam combination are required to be plated on two inclined end faces of the parallelogram crystal respectively, so that a higher level is required in the film plating process. Finally, when bonding two triangular crystals at both ends of a parallelogram, the demands on the bonding process, such as bonding glue, clamps, etc., require extremely high precision. Thus, the process and cost required to fabricate such smaller sized PBCs are relatively high, with low product yield and stability.

2. Half-wave plate and PBC performance. Since the beam combination method completely depends on the polarization state of the laser, the performance of the half-wave plate and the PBC is very important. However, such small size of the half-wave plate and the special film system for polarization beam combination with high extinction ratio are both risks and difficulties of this method.

Coupling process of PBC. The PBC is characterized in that two laser beams with mutually orthogonal polarization directions can be combined, so that when the TOSA device has more than two (integral multiple of 2) channels, a plurality of PBCs are needed for realizing the combination, and thus, the coupling and bonding of the plurality of PBCs have extremely high requirements on the coupling capability of the fixture and the bonding process. In addition, since the beam combining performance of PBC is sensitive to the angle of incident light, it is also a challenge to make the beam normal incidence to coupling technology for each PBC crystal.

Based on this, the present application intends to provide a technical solution capable of solving the above technical problems, which will be specifically explained in the following embodiments.

Fig. 1 is a top view of a multi-beam combining module according to an embodiment of the present disclosure. The multi-beam combination assembly is used for coupling a plurality of incident signal lights (not shown in fig. 1) into one emergent light (not shown in fig. 1), the assembly comprises two reflectors, openings of the two reflectors are oppositely arranged, the projections of the two reflectors on a first set plane are not overlapped, the projections of the two reflectors on a second set plane are parabolas, and the optical axes 1002 and the focuses 1004 of the two parabolas are overlapped; the two reflectors are obtained by respectively moving the projections on the second set plane by a preset distance along the direction vertical to the second set plane; the first setting plane and the second setting plane are perpendicular to each other.

Wherein, the two reflectors are respectively marked as a first reflector 110 and a second reflector 120; multiple beams of signal light incident along the optical axis 1002 are reflected by the first reflecting mirror 110 and then converged at the focus 1004, the converged signal light is reflected by the second reflecting mirror 120 and then coupled into a beam of emergent light, and the emergent light is parallel to the optical axis 1002.

In this embodiment, the first setting plane may be an XOZ plane or a YOZ plane, and may be an XOZ plane; the second setting plane may be an XOY plane. When the first setting plane is an XOZ plane and the second setting plane is an XOY plane, the two reflectors of the present application are specifically configured by moving (translating) their projection (parabola) on the XOY plane in a direction perpendicular to the XOZ plane by a preset distance, which is the height of the reflector on the XOZ plane. It will be appreciated that the heights of the two mirrors in the present application may be different, depending primarily on the actual requirements of the product in use.

The multi-beam combining module and the core first mirror 110 and the core second mirror 120 of the multi-beam combining module are briefly described above, and in order to make those skilled in the art more deeply understand the technical solution of the present invention, the beam combining principle is described below to describe the obtaining process of the structural parameters of the multi-beam combining module of the present invention.

Referring to fig. 1, a modulated light beam λ 1 emitted by a laser (not shown in fig. 1) is collimated by a collimating lens (not shown in fig. 1) into a parallel light beam parallel to an optical axis 1002 of a first reflector 110, and since a projection of the reflector on an XOY plane is a parabola, according to the geometrical and optical characteristics of the parabola, any light beam parallel to a main axis is incident on the parabola, and a reflected light beam necessarily passes through a focal point of the parabola, the first reflector 110 converges the parallel light beam at the focal point 1004, and the optical axis 1002 of the first reflector 110 is an axisymmetric center of the first reflector 110. Since the optical axis and the focal point of the second mirror 120 are both coincident with those of the first mirror 110, it can be seen from the geometrical optics of the parabola that any light incident to the parabola via the focal point must be parallel to the optical axis of the parabola, so the second mirror 120 will reflect the light beam incident from the focal point 1004 into an outgoing light beam parallel to the optical axis. Further, in order to combine the light beams and achieve the function of combining multiple light beams, the signal light beams in this embodiment may be multiple light beams, which are usually integer multiples of 2, and the multiple signal light beams may be incident on the first reflecting mirror 110 at the same horizontal plane. In this embodiment, four signal beams are taken as an example for illustration, based on the aforementioned light transmission principle, the four signal beams are reflected by the first reflecting mirror 110 and then converged at the focus 1004, and then reflected by the second reflecting mirror 120 and coupled into an outgoing light beam parallel to the optical axis 1002, specifically, the diameter of the outgoing light beam after coupling the multiple light beams by the multi-beam combining assembly of the present application can be controlled within 0.4mm, so as to achieve the multi-beam combining function of the present application.

It is understood that, in order to implement the reflection and emission functions, the present application further plates an HR (high reflection) film in the infrared band on the first reflecting mirror 110 and the second reflecting mirror 120, and further plates an AR (anti-reflection) film in the infrared band on the light outgoing region of the multi-beam combining assembly, and the thickness of the film layer can be selected and adjusted according to the performance of the product and the actual needs of those skilled in the art. Furthermore, the material of each of the first mirror 110 and the second mirror 120 may be common K9 optical glass.

Furthermore, as an embodiment for realizing the above function, a projection of the first reflecting mirror 110 on the second setting plane (XOY plane) is denoted as a first parabola, and the first parabola is: y is²32X; the projection of the second mirror 120 on the second setting plane (XOY plane) is denoted as a second parabola, which is: y is²＝4X。

In some embodiments, first mirror 110 and second mirror 120 may be packaged as a single structure, and the transmission medium inside the single structure may include air or vacuum, as compared to the transmission of a conventional light beam that is generally inside the material. Further, the first reflector 110 and the second reflector 120 may be formed in one step by opening a mold. The molded first reflector 110 and second reflector 120 are then packaged as a single structure.

In summary, the multi-beam combining assembly of the present application has the following advantages:

1. the light path structure is simple. The multi-beam combination component only utilizes the special optical characteristics of the parabolic reflecting surface to spatially compress the multi-path signal light into one emergent light beam.

2. The requirement for the coating process is low. The multi-beam combining component only needs to plate an HR film and an AR film in an infrared band on a specific end face, does not need to be coated with narrow-band light filtering films with different central wavelengths like a TFF (thin film filter), and does not need to be coated with a polarization beam combining film like a PBC (polarization beam combiner).

3. The manufacturing process is simple. The multi-beam combination assembly can be formed in one step through a die opening mode, and subsequent bonding and other processes are not needed.

4. The optical tolerances are large. The basic structure of the multi-beam combination assembly is a parabolic reflecting surface with coincident focal points, so that the process of transmitting beams in the parabolic reflecting surface is similar to conjugation. When the dimensions of the component are sufficiently large within reasonable limits, the tolerances for translation in the direction along the plane of the component and in the direction perpendicular to the plane of the component are large. Therefore, the component can reduce the cost of the coupling process.

Based on the same inventive concept, the present application further provides a light emitting assembly, which may comprise the multi-beam combining assembly according to any of the previous embodiments. Therefore, reference may be made to the foregoing embodiments for a description of the multi-beam combining assembly, which will not be further described herein, and only differences will be described.

In some embodiments, reference may be made to both fig. 2 and 3; the light emitting module may include, in addition to the multi-beam combining module described above, a laser module (which may be understood as a laser that radiates signal light having wavelengths λ 1, λ 2, λ 3, and λ 4) and a collimating module (which may be understood as a collimating lens that collimates the signal light having wavelengths λ 1, λ 2, λ 3, and λ 4, respectively); specifically, a plurality of signal lights (λ 1, λ 2, λ 3, and λ 4) radiated by the laser module are collimated by the collimating module and then incident on the multi-beam combining assembly, and are coupled into a signal light by the multi-beam combining assembly and then emitted from an optical exit region of the multi-beam combining assembly. Further, as can be seen from the foregoing description, the laser module in this embodiment may include four lasers, two lasers, and eight lasers, which respectively radiate signal light with wavelengths λ 1, λ 2, λ 3, and λ 4; correspondingly, the laser module comprising two lasers is a dual-channel laser module, the laser module comprising four lasers is a four-channel laser module, and the laser module comprising eight lasers is an eight-channel laser module. It will be appreciated that the number of collimating lenses in the collimating module should correspond one-to-one to the number of lasers in the laser module. Further, the light emitting component in this embodiment may include a circular light emitting component, that is, a light emitting component using a TOCAN package, or a square light emitting component, that is, a light emitting component using a BOX package.

As can be seen from the foregoing, the multi-beam combining assembly of the present application can be compatible with two-channel, four-channel, eight-channel, etc. laser modules without increasing the number thereof, and has lower cost and higher compatibility compared to the multi-beam collection method of the polarization beam combiner.

The structural parameters of the multi-beam combining assembly will be described below in conjunction with the emission light assembly. Continuing to refer to FIG. 2, a top view of the light emitting assembly in one embodiment is shown. It should be noted that the parameters herein represent the dimensional parameters of the multi-beam combining module in the two-dimensional projection of the second setting plane, specifically, a1 represents the light exiting region of the emitting light module, a2 represents the internal space of the housing of the emitting light module, R represents the clear radius of the light region, α represents the angle between the outer side of the light beam reflected by the first reflector 110 and the optical axis 1002, d represents the angle between the outer side of the light beam λ 1 and the optical axis 1002, and d represents the angle between the outer side of the light beam reflected by the first reflector 110₁Denotes a distance between one of the incident plurality of signal lights (λ 1 in fig. 2) farthest from the optical axis 1002 and the optical axis 1002, and is generally referred to as a signal light λ 1Outer side of d₂The distance between the same signal light λ 1 reflected and collimated by the second mirror 120 and the optical axis 1002 is also indicated here as the outer side of the signal light λ 1.

Combining the foregoing light transmission principles, and from simple geometric relationships, it can be understood that the focal length of the first reflector 110 and the focal length of the second reflector 120 satisfy the following equations:

wherein f is₁Is the focal length of the first mirror, f₂The focal length of the second reflector, the first distance d for a square-shaped emitting light assembly₁A second distance d₂Focal length f of the first reflector₁Focal length f of the second mirror₂The following constraints may also be satisfied:

d₂<R

f₁+f₂<L₁

by combining the above two formulas, the focal length f meeting the specific requirement can be solved₁And f₂。

In particular, taking the internal space of a four-channel BOX-type light-emitting module with a channel spacing of 0.75mm, which is commonly used in the art, as an example, a reasonable set of values, f, can be released according to the above equation and constraint conditions₁＝8mm，f ₂1 mm. The value is brought into ZEMAX for simulation, a simulation light path system is shown in figure 3, and four signal light beams have focal lengths of f₁8mm and f₂After 1mm of parabolic reflection, the beams are spatially converged and output through an output window. The simulation result is shown in fig. 4, the two

reflectors

110 and 120 successfully compress the four-path signal light to within 0.4mm (longitudinal space) in space, and from the simulation result, the obtained focal lengths of the two

reflectors

110 and 120 are alsoA focal length of a parabola that is satisfied by the paraboloids of the two

aforementioned reflectors

110 and 120; the four signal lights output by the output window can then be focused into the fiber with a small off-axis phase difference via a focusing lens (clear aperture is typically about 1.4mm) in the fiber adapter. In addition, the four light spots are basically symmetrical, and no obvious coma aberration exists (spherical aberration does not exist in the imaging system of a single parabolic reflecting surface, but coma aberration exists).

Based on the same inventive concept, the application also provides an optical module, which comprises a TOSA module and a ROSA module; wherein, the TOSA module is the aforementioned light emitting component. Therefore, reference may be made to the foregoing embodiments for a description of the multi-beam combining assembly, which will not be further described herein, and only differences will be described.

In some embodiments, the optical module should further have a limiting amplifier chip and a laser driver chip, which are integrated on a printed circuit board with the ROSA module and the TOSA module, respectively. Although not shown, the connection and cooperation relationship between the limiting amplification chip and the laser driving chip and between the modules can be known to those skilled in the art based on the prior art.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A multi-beam combination component is used for coupling a plurality of incident signal beams into a beam of emergent light and is characterized by comprising two reflectors, wherein openings of the two reflectors are oppositely arranged, and the projections of the two reflectors on a first set plane are not overlapped; the projections of the two reflectors on the second set plane are parabolas, the optical axes and the focuses of the two parabolas are coincident, and the two reflectors are obtained by respectively moving the projections on the second set plane by a preset distance along the direction vertical to the second set plane; the first setting plane and the second setting plane are perpendicular to each other;

wherein, the two reflectors are respectively marked as a first reflector and a second reflector; a plurality of beams of signal light incident along the optical axis are reflected by the first reflecting mirror and then converged at the focus, the converged signal light is reflected by the second reflecting mirror and then coupled into a beam of emergent light, and the emergent light is parallel to the optical axis;

the optical axis of the first reflector is the axisymmetric center of the first reflector;

the focal length of the first reflector in the multi-beam combination assembly is recorded as f₁The focal length of the second reflector is denoted as f₂，f₁、f₂Satisfies the formula:

wherein d is₁Denotes a first distance, d₂Represents a second distance; the first distance represents the distance between one beam of signal light farthest from the optical axis in the incident multiple beams of signal light and the optical axis under the projection of the multiple-beam combining assembly on the second set plane; the second distance represents a distance between the beam of signal light reflected and collimated by the second reflector and the optical axis under the projection of the multi-beam combining assembly on the second set plane.

2. The multi-beam combining assembly of claim 1, wherein the plurality of signal beams are incident on the first mirror at a same horizontal plane.

3. The multi-beam combining assembly of claim 2, wherein the projection of the first mirror onto the second setting plane is denoted as a first parabola, and the first parabola is: y is²＝32X。

4. The multi-beam combining assembly of claim 2, wherein the projection of the second mirror onto the second setting plane is denoted as a second parabola, and the second parabola is: y is²＝4X。

5. The multi-beam combining assembly of any one of claims 1-4, wherein the first mirror and the second mirror are packaged as a unitary structure, and the transmission medium inside the unitary structure is air or vacuum.

6. The multi-beam combining assembly of any one of claims 1-4, wherein the first reflector and the second reflector are formed in one piece using an open mold.

7. The multi-beam combining assembly of any of claims 1-4, wherein the diameter of the exiting light is less than 0.4 mm.

8. An optical assembly for emitting light, comprising the multi-beam combining assembly of any one of claims 1-7.

9. The light emitting assembly of claim 8, further comprising a laser module and a collimation module;

10. The light emitting assembly of claim 9, wherein the laser module comprises any one of a dual channel type laser module, a four channel type laser module, and an eight channel type laser module.

11. The light emitting assembly of claim 9, wherein the light emitting assembly comprises a circular light emitting assembly or a square light emitting assembly.

12. The light emitting assembly of claim 8, wherein the light emitting assembly is a square light emitting assembly, and the first distance d is₁A second distance d₂Focal length f of the first reflector₁Focal length f of the second mirror₂The following constraints are satisfied:

d₂＜R

f₁+f₂＜L₁

13. An optical module is characterized by comprising a TOSA module and a ROSA module;

wherein the TOSA module is the transmitter optical assembly of any one of claims 8-12.