CN209784593U

CN209784593U - Light receiving device and system

Info

Publication number: CN209784593U
Application number: CN201920439114.4U
Authority: CN
Inventors: 张衎; 雷奖清; 朱腾飞
Original assignee: Ona Information Technology (shenzhen) Co Ltd
Current assignee: Ona Information Technology (shenzhen) Co Ltd
Priority date: 2019-04-02
Filing date: 2019-04-02
Publication date: 2019-12-13
Anticipated expiration: 2029-04-02

Abstract

the utility model relates to an optical device field, concretely relates to light receiving device, light receiving device includes tube socket and tube cap, the tube cap is provided with lens and the dielectric sheet that has the high refracting index, the tube socket is provided with the PD chip, wherein, the light beam shoots to the dielectric sheet after passing through outside optic fibre and lens transmission, the light beam is received by the PD chip after making the working distance elongate through the dielectric sheet; compared with the prior art, the utility model discloses a design a light receiving device for still can obtain maximum coupling efficiency under the structure restriction condition, wherein, through the silicon chip that has the high refracting index in the pipe cap setting, make working distance elongated, thereby guarantee its maximum coupling efficiency.

Description

Light receiving device and system

Technical Field

The utility model relates to an optical device field, concretely relates to light receiving device and system.

Background

ROSA (Receiver Optical Subassembly) is an Optical receiving component, and is mainly used for converting an Optical signal into an electrical signal (O/E conversion), the coupling efficiency of the ROSA is an important performance index of the ROSA, for a single-lens coupling system, there is an optimal combination of object distance and image distance, the working distance is the distance between PD and lens time, and when the working distance is matched with the image distance of the Optical system (the focusing position of a light beam is matched with the distance between lenses), the coupling efficiency of the system is maximum. If the working distance is less than or greater than the image distance (also called over-focus and under-focus), the coupling efficiency will decrease.

Due to the limitation of the structural design, the condition of the optimal combination of the object distance and the image distance cannot be satisfied, that is, the coupling efficiency cannot reach the optimal value, and when the receiving distance (image distance) is elongated, the working distance (focal length of the light beam) is smaller than the image distance, and the maximum coupling efficiency of the system cannot be maintained.

therefore, it has been a problem of intensive research in the art to design a light receiving device that can achieve optimal coupling efficiency even when the image distance is elongated.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, to the above-mentioned defect of prior art, provide a light receiving device, overcome the defect that can't compromise maximum coupling efficiency and structural requirement simultaneously among the current device.

In order to solve the technical problem, the utility model provides a light receiving device, light receiving device includes tube socket and tube cap, and its preferred scheme lies in the tube cap is provided with lens and the medium thin slice that has the high refractive index, the tube socket is provided with the PD chip, and wherein, the directive medium thin slice after the light beam passes through outside optic fibre and lens transmission, and the light beam makes working distance elongate through the medium thin slice and is received by the PD chip.

Preferably, the dielectric sheet is disposed between the lens and the PD chip.

the transparent surface of the medium slice is plated with an antireflection film for increasing the intensity of the transmitted light beam.

preferably, the thickness of the medium sheet is matched with the image distance.

Wherein, the preferred scheme is that the medium slice is a silicon slice.

The tube cap further comprises a gasket for supporting a silicon wafer, and the silicon wafer is adhered to the tube cap through the gasket.

to the above-mentioned defects in the prior art, the present invention further provides a light receiving system, which includes the light receiving device as described above, and the preferred solution thereof lies in: the light receiving system also comprises an optical fiber, the light beam is transmitted to the medium sheet through the optical fiber and the lens, and the light beam is received by the PD chip after the working distance is elongated through the medium sheet.

The beneficial effects of the utility model reside in that, compared with the prior art, the utility model discloses a design a light receiving device for still can obtain maximum coupling efficiency under the structure restriction condition, wherein, through the silicon chip that has the high refracting index in the pipe cap setting, make working distance elongated, thereby guarantee its maximum coupling efficiency.

Drawings

The invention will be further explained with reference to the drawings and examples, wherein:

fig. 1 is a schematic structural diagram of an optical receiver system according to the present invention;

Fig. 2 is a light path diagram of the light receiving device according to the present invention when receiving light;

Fig. 3 is a first schematic diagram of the optical path of the optical receiver of the present invention;

FIG. 4 is a schematic diagram of the optical path of the optical receiver of the present invention;

Fig. 5 is a third schematic diagram of the optical path of the optical receiver according to the present invention.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in fig. 1, the present invention provides a preferred embodiment of a light receiving system.

The light receiving system comprises an optical fiber 100, a tube holder and a tube cap 300, wherein the tube cap 300 is provided with a lens 310 and a dielectric sheet 320 with a high refractive index, the tube holder is provided with a PD chip 200, the dielectric sheet 320 is arranged between the lens 310 and the PD chip, the light beam is transmitted to the dielectric sheet 320 through the optical fiber 100 and the lens 310, and the light beam is received by the PD chip 200 after the working distance (the focal length of the light beam) is elongated through the dielectric sheet 320.

Further, the cap 300 further includes a gasket 330, and the gasket 330 is used for supporting the media sheet 320.

Since the high refractive index material is required for the extended focal length, and the higher transmittance or the lower absorption rate is also required, the dielectric sheet 320 may be made of cut pieces and inp material, and since the silicon wafer has a high refractive index, the light beam may be refracted through the silicon wafer, and the working distance is extended, so as to ensure that the optical transmission component still has the optimal coupling efficiency under the structural limitation, so the silicon wafer is preferably selected as the dielectric sheet 320 in this embodiment.

The gasket is made of metal which is close to the CAP material, the expansion coefficients are close, so that the stress between the CAP and the gasket is small, the stability of the product is improved, and the gasket and the CAP as well as the silicon wafer and the gasket are bonded through epoxy glue.

According to optical simulation, the coupling efficiency tolerance of the obtained silicon wafer is better, namely the coupling efficiency change caused by small displacement of each part is effective, the product is more stable, but due to structural limitation, the maximum thickness of the silicon wafer is 1.66mm, and the specific thickness of the silicon wafer is determined according to a specific structure.

The specific installation steps are as follows:

Firstly, bonding a silicon wafer on a gasket through glue;

then, placing the gasket bonded with the silicon wafer in the pipe CAP, and fixing the gasket bonded with the silicon wafer in the pipe CAP through glue TO form TO CAP;

Further, bonding and fixing the PD chip on the tube seat;

Further, the pipe cap with the adhered gasket and the silicon chip and the pipe seat with the adhered PD chip are adhered and fixed TO form a TO CAN;

And finally, coupling and fixing the TO CAN and the optical fiber TO form the ROSA.

ROSA (Receiver Optical Subassembly) refers to an Optical Receiver of the present invention, and is mainly applied to converting an Optical signal into an electrical signal (O/E conversion).

The light-transmitting surface of the dielectric sheet 320 is coated with an antireflection film for increasing the intensity of the transmitted light beam.

wherein the thickness of the dielectric sheet is matched to the image distance (distance between the back surface of the lens and the focus position of the light beam).

As shown in fig. 2, the present invention provides an optical path diagram when the light receiving device receives light.

The light beam is emitted through the optical fiber 100, then, is emitted to the silicon chip 320 through the lens 310, and further, the light beam passes through the silicon chip 320 so that its working distance (focal length of the light beam) is elongated, and finally, is emitted to the PD chip 200 to be received by it.

as shown in fig. 3 to 5, the present invention provides a schematic diagram of an optical path of the light receiving device.

Referring to fig. 3, the distance from the optical fiber 100 to the lens 310 is an object distance L1, the distance from the lens 310 to the PD chip 200 is an image distance L2, and the working distance (focal length of the light beam) is L2 ', when L2 ' is L2, L2 ' is an optimal working distance, and at this time, the coupling efficiency is the highest when the optimal object distance and the image distance are combined.

Referring to fig. 4, when a ROSA design needs to increase the image distance L2, the L2 distance increases, while the working distance L2 'does not change, and the working distance L2' does not match the image distance L2, resulting in a low receiving efficiency, i.e., a low coupling efficiency.

Referring to fig. 5, when the silicon wafer 320 is added between the lens 310 and the PD chip 400, since the silicon wafer has a high refractive index, the working distance L2 'is elongated, and the thickness of the silicon wafer 320 can be determined according to the distance of the image distance L2, thereby ensuring that the working distance L2' is equal to the image distance L2, thereby obtaining an optimal working distance and thus ensuring an optimal coupling efficiency thereof.

In summary, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A light receiving device comprising a stem and a cap, characterized in that: the tube cap is provided with a lens and a dielectric sheet with a high refractive index, the tube seat is provided with a PD chip, wherein, the light beam is transmitted to the dielectric sheet through an external optical fiber and the lens, and the light beam is received by the PD chip after the working distance is elongated through the dielectric sheet.

2. The light receiving device according to claim 1, wherein: the dielectric sheet is disposed between the lens and the PD chip.

3. The light receiving device according to claim 2, wherein: and the light-transmitting surface of the medium sheet is plated with an antireflection film for increasing the intensity of a transmitted light beam.

4. A light receiving device according to claim 3, wherein: the thickness of the medium slice is matched with the image distance.

5. the light receiving device according to claim 1, wherein: the dielectric sheet is a silicon wafer.

6. The light receiving device according to claim 5, wherein: the pipe cap also comprises a gasket for supporting a silicon wafer, and the silicon wafer is adhered to the pipe cap through the gasket.

7. A light receiving system comprising the light receiving device according to claims 1 to 6, characterized in that: the light receiving system also comprises an optical fiber, the light beam is transmitted to the medium sheet through the external optical fiber and the lens, and the light beam is received by the PD chip after the working distance is elongated through the medium sheet.