CN107222265A

CN107222265A - Optical module

Info

Publication number: CN107222265A
Application number: CN201710348021.6A
Authority: CN
Inventors: 左瑜
Original assignee: Xian Cresun Innovation Technology Co Ltd
Current assignee: Xian Cresun Innovation Technology Co Ltd
Priority date: 2017-05-17
Filing date: 2017-05-17
Publication date: 2017-09-29

Abstract

The present invention relates to a kind of optical module, including：Light emitting devices and optical pickup apparatus, wherein, the light emitting devices includes the infrared light supply (1) and infrared light supply drive circuit (2) that are electrically connected to each other, and discharge road (4) and main amplifier (5) before PIN detector (3) that optical pickup apparatus includes being sequentially connected, PIN detector；The light emitting devices generates optical signal after treatment for receiving electric signal, and the optical pickup apparatus exports electric signal for receiving the optical signal after processing.The optical module that the present invention is provided, cost is low, low in energy consumption, and luminous efficiency is stable, is not influenceed by the change of temperature, and reliability is high.

Description

Optical module

Technical Field

The invention belongs to the technical field of optical fiber communication, and particularly relates to an optical module.

Background

The optical module (TransceiverModule) comprises an optoelectronic device, a functional circuit, an optical interface and the like, wherein the optoelectronic device comprises a transmitting part and a receiving part. The transmit part is typically: the electric signal with a certain code rate is processed by an internal driving chip to drive a semiconductor Laser (LD) to emit a modulated optical signal with a corresponding rate, and an optical power automatic control circuit is arranged in the laser diode to keep the power of the output optical signal stable. The receiving part is typically: the optical signal with a certain code rate is input into the module and then converted into an electric signal by the optical detection diode. After passing through the preamplifier, the electric signal with corresponding code rate is output. In brief, the optical module functions as a photoelectric converter, the transmitting end converts an electrical signal into an optical signal, and the receiving end converts the optical signal into the electrical signal after the optical signal is transmitted through the optical fiber.

An optical module is widely applied as a basic component in the field of optical fiber communication, however, for an optical module using a semiconductor laser as a light source, the cost and the power consumption are always high, the luminous efficiency is unstable, and especially under the conditions of high temperature and severe temperature change, the unstable luminous efficiency is more prominent, and the reliability is poor.

Disclosure of Invention

In order to solve the above technical problem, the present invention provides an optical module.

The embodiment of the invention provides an optical module, which comprises a light emitting device and a light receiving device, wherein the light emitting device comprises an infrared light source (1) and an infrared light source driving circuit (2) which are electrically connected with each other, and the light receiving device comprises a PIN detector (3), a PIN detector front-amplifying circuit (4) and a main amplifier (5) which are sequentially connected;

the light emitting device is used for receiving the electrical signal and generating an optical signal after processing, and the light receiving device is used for receiving the optical signal and outputting the electrical signal after processing.

In the embodiment provided by the invention, the PIN detector (3) comprises an optoelectronic TO-CAN (31), a metal tube body (32), a connecting block (33) and an optical fiber (34) which are sequentially connected.

In embodiments provided herein, the optoelectronic TO-CAN (31) includes a cap (311) and a lens (312).

In the embodiment provided by the invention, the system further comprises an error code detector (6) which is electrically connected with the signal output end of the main amplifier (5) and is used for detecting the error rate of signal transmission.

In the embodiment provided by the invention, the device further comprises a signal delay circuit (7), wherein the signal delay circuit (7) is electrically connected with the signal output end of the main amplifier (5) and the input end of the error detector (6) and is used for performing delay processing on the electric signal output by the main amplifier (5).

In the embodiment provided by the invention, the device further comprises a switch (8) which is connected with the signal delay circuit (7) in parallel.

In the embodiment provided by the invention, the infrared light source (1) comprises an infrared LED (10), a substrate (11), a lens (12), a gold wire (13) and a resin material (14); wherein,

the infrared LED (10) is positioned at a middle groove portion of the substrate (11);

two ends of the gold wire (13) are respectively connected with the metal wire on the substrate (11) and the infrared LED (10);

the lens (12) is positioned on the substrate (11) and is fixedly connected with the substrate (11);

the resin material (14) is located in a cavity formed by the substrate (11) and the lens (12).

In the embodiment provided by the invention, the light-emitting wavelength of the infrared LED (10) is 1550 nm-1650 nm.

In an embodiment provided by the invention, the infrared LED (10) comprises: the semiconductor device comprises a substrate (101), a P-type crystallized Ge layer (102), an intrinsic Ge layer (103), an N-type Ge layer (104) and a passivation layer (105);

wherein the P-type crystallized Ge layer (102), the intrinsic Ge layer (103), the N-type Ge layer (104) and the passivation layer (105) are sequentially laminated on the substrate (101).

In the embodiment provided by the invention, the infrared LED (10) further comprises a positive electrode (106) and a negative electrode (107), and the positive electrode (106) and the negative electrode (107) are respectively connected with the P-type crystallized Ge layer (102) and the N-type Ge layer (104).

The optical module provided by the invention has the advantages of low cost, low power consumption, stable luminous efficiency, no influence of temperature change and high reliability.

Drawings

The following detailed description of embodiments of the invention will be made with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of an optical module according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a PIN detector according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an optoelectronic TO-CAN provided by an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another optical module according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of another optical module according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an infrared light source according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of an infrared LED according to an embodiment of the present invention;

FIGS. 8 a-8 m are schematic diagrams illustrating a method for fabricating an infrared LED according to an embodiment of the present invention;

fig. 9 is a schematic diagram of an LRC process according to an embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

Example one

Referring to fig. 1, fig. 1 is a schematic structural diagram of an optical module according to an embodiment of the present invention, where the optical module includes:

the device comprises a light emitting device and a light receiving device, wherein the light emitting device comprises an infrared light source (1) and an infrared light source driving circuit (2) which are electrically connected with each other, and the light receiving device comprises a PIN detector (3), a PIN detector front-amplifying circuit (4) and a main amplifier (5) which are sequentially connected;

The embodiment adopts the infrared light source as the light emitting device, and has the advantages of low cost, low power consumption, stable luminous efficiency, no influence of temperature change and high reliability.

Further, on the basis of the above embodiment, please refer to fig. 2, and fig. 2 is a schematic structural diagram of a PIN detector (3) according to an embodiment of the present invention. The PIN detector (3) comprises a photoelectric TO-CAN (31), (namely a Transistor Outline CAN type packaging tube), a metal tube body (32), a connecting block (33) and an optical fiber (34) which are sequentially connected.

Further, on the basis of the above embodiments, please refer TO fig. 3, and fig. 3 is a schematic structural diagram of an optoelectronic TO-CAN (31) according TO an embodiment of the present invention. The opto-electric TO-CAN (31) comprises a cap (311) and a lens (312).

In the optical module provided in the above embodiments, the output electrical signal has a certain delay relative to the input signal, and the delay varies with the distance of the optical fiber. If the signal delay phenomenon is processed, the signal transmission error rate of the optical module is influenced. Although some time synchronization methods exist in the prior art to suppress the delay phenomenon, redesign is needed from the aspects of coding and decoding, synchronous circuit design and the like, and the method is high in cost, poor in universality and difficult to popularize on a large scale.

On the basis of the above embodiments, please refer to fig. 4, where fig. 4 is a schematic structural diagram of another optical module provided in the embodiments of the present invention, and in order to further improve the reliability of the optical module, the optical module provided in this embodiment further includes an error code detector (6) electrically connected to a signal output end of the main amplifier (5) and configured to detect an error code rate of signal transmission.

The reason why the error rate is high is that the digital signal is at the rising edge or the falling edge of the digital signal at the time of processing the digital signal, and therefore, if the received digital signal is delayed to some extent, the error rate can be reduced more significantly by avoiding the processing of the signal at the rising edge or the falling edge of the digital signal.

Based on this, please refer to fig. 5, fig. 5 is a schematic structural diagram of another optical module according to an embodiment of the present invention, and the optical module according to the embodiment of the present invention further includes a signal delay circuit (7), where the signal delay circuit (7) is electrically connected to the signal output end of the main amplifier (5) and the input end of the error detector (6), and is configured to perform delay processing on the electrical signal output by the main amplifier (5). Preferably, the signal delay circuit (7) is controllable in the degree of signal delay.

Further, on the basis of the above embodiment, another optical module provided by the present invention further includes a switch (8), and the switch is connected in parallel with the signal delay circuit (7). When the switch is in a closed state, the signal delay circuit (7) stops working, and a user can determine whether signal delay is needed according to actual needs, for example, the user can determine whether the signal delay circuit needs to be started according to the indicated error rate of the error detector (6).

Example two

In the present embodiment, in addition to the above embodiments, the emission wavelength of the infrared LED (10) is preferably 1550nm to 1650 nm.

Referring to fig. 6, fig. 6 is a schematic structural diagram of an infrared light source used in an infrared optical module according to an embodiment of the present invention. The infrared light source block includes a substrate (11), a lens (12), a gold wire (13), and a resin material (14).

Wherein the infrared LED (10) is located at a middle groove portion of the substrate (11);

the gold wire (13) is used for connecting a metal wire on the substrate (11) and the infrared LED (10);

the lens (12) is fixedly connected to the substrate (11) and is fixedly connected with the substrate (11);

EXAMPLE III

Referring to fig. 7, fig. 7 is a schematic structural diagram of an infrared LED (10) according to an embodiment of the present invention, where the infrared LED (10) includes:

the semiconductor device comprises a substrate (101), a P-type crystallized Ge layer (102), an intrinsic Ge layer (103), an N-type Ge layer (104) and a passivation layer (105);

Further, on the basis of the above embodiment, the P-type crystallized Ge layer and the N-type crystallized Ge layer are further included, wherein the positive electrode (106) and the negative electrode (107) are respectively connected to the P-type crystallized Ge layer (102) and the N-type crystallized Ge layer (104).

Further, on the basis of the above embodiment, both the positive electrode (106) and the negative electrode (107) are made of Cr — Au alloy material.

Further, on the basis of the above embodiment, the substrate (101) is a single crystal Si material.

Further, on the basis of the above embodiment, the thickness of the P-type crystallized Ge layer (102) is 190-200 nm, and the doping concentration is 5 × 10¹⁸cm^-3。

Further, on the basis of the above embodiment, the P-type crystallized Ge layer (102) is obtained by processing the Ge epitaxial layer grown on the substrate (101) by using a laser recrystallization process, wherein the parameters of the laser recrystallization process are that the laser wavelength is 808nm, the laser spot size is 10mm × 1mm, and the laser power is 1.5kW/cm²The laser moving speed was 25 mm/s.

Further, in the above embodiment, the intrinsic Ge layer (103) includes a first Ge barrier layer (1031), a GeSn layer (1032), and a second Ge barrier layer (1033), and the first Ge barrier layer (1031), the GeSn layer (1032), and the second Ge barrier layer (1033) are sequentially stacked.

Further, on the basis of the above embodiment, the thickness of the first Ge barrier layer (1031) is 12-18nm, the thickness of the GeSn layer (1032) is 150-200 nm, and the thickness of the second Ge barrier layer (1033) is 400-450 nm.

Further, on the basis of the above embodiment, the thickness of the N-type Ge layer (104) is 100-120 nm.

According to the GeSn material-based LED provided by the embodiment of the invention, GeSn is adopted to replace Ge to be used as a light source in a photoelectric integrated circuit, so that the luminous efficiency is improved, the defect expansion is effectively inhibited, and a high-quality Ge/Si virtual substrate is obtained; and moreover, a Ge barrier layer structure is introduced between the Ge doping layer and the GeSn intrinsic layer, so that the unintentional doping of the GeSn by a doping source of the Ge layer can be avoided, and the performance of the device is improved.

Example four

Referring to fig. 8a to 8m, fig. 8a to 8m are schematic diagrams illustrating a method for manufacturing an infrared LED (10), according to an embodiment of the present invention, the method includes the following steps:

s101, selecting a single crystal Si substrate 001 as shown in FIG. 8 a.

S102, growing a Ge seed layer 002 of 40-50 nm on a single crystal Si substrate 001 by using a CVD process at the temperature of 250-350 ℃, as shown in figure 8 b.

S103, growing a 150-250 nm Ge main body layer 003 on the surface of the Ge seed crystal layer 002 by utilizing a CVD process at the temperature of 550-600 ℃, as shown in figure 8 c.

S104, growing SiO with the thickness of 100-150 nm on the surface of the Ge main body layer 003 by utilizing a CVD process₂Protective layer 004, as shown in fig. 8 d.

S105, heating the whole substrate material comprising the single crystal Si substrate 001, the Ge seed layer 002 and the Ge main body layer 003 to 700 ℃, continuously processing the whole substrate material by utilizing a laser recrystallization process to obtain a crystallized Ge layer 005, and naturally cooling the whole substrate material, wherein the laser wavelength is 808nm, the laser spot size is 10mm × 1mm, and the laser power is 1.5kW/cm²The laser moving speed was 25 mm/s.

S106, etching SiO by utilizing a dry etching process₂Protecting the layer resulting in a crystallized Ge layer 005 as shown in fig. 8 e.

S107, doping the crystallized Ge layer 005 by using an ion implantation process, wherein the doping concentration is 5 × 10¹⁸cm^-3A P-type crystallized Ge layer 006 is formed and then the entire material is annealed as shown in fig. 8 f.

S108, growing a first Ge barrier layer 007 of 12-18nm on the P-type crystallized Ge layer 006 by a CVD process at a temperature of 300-350 ℃, as shown in FIG. 8 g.

S109 at H₂Reducing the temperature to below 350 ℃ in the atmosphere, SnCl₄And GeH₄Respectively used as Sn and Ge sources, the Sn component is 8 percent, the Ge-doped component is 92 percent, and a 150-200 nm GeSn layer 008 grows on the first Ge barrier layer 007 as shown in the figureShown in 8 h.

S110, growing a second Ge barrier layer 009 of 400-450nm on the GeSn layer 008 at the temperature of 300-350 ℃ by using a CVD process, as shown in FIG. 8 i.

And S111, growing an N-type Ge layer 010. The temperature is reduced to below 350 deg.C, and Ge layer is grown on the second Ge barrier layer 009 by using N₂As a carrier gas, the growth rate can be increased at pH₃As a P doping source, the P doping concentration is 1 × 10¹⁹cm^-3Then, a 100-120nm N-type Ge layer structure 010 is formed, as shown in FIG. 8 j.

And S112, etching away the designated area comprising the first Ge barrier layer, the GeSn layer and the second Ge barrier layer by utilizing an etching process at room temperature to expose the P-type crystallized Ge layer to be used as a metal contact mesa of the P-type crystallized Ge layer, as shown in figure 8 k.

S113, growing SiO on the metal contact table top of the P-type crystallized Ge layer and the N-type Ge layer by utilizing a plasma enhanced chemical vapor deposition process₂A passivation layer 011 for isolating the mesa from external electrical contact and selectively etching SiO by etching process₂The passivation layer 011 is formed with a P-type Ge layer contact hole and an N-type Ge layer contact hole, respectively, as shown in FIG. 8 l.

S114, growing 150-200 nm Cr-Au alloy 012 serving as electrodes in the contact hole regions of the P-type Ge layer and the contact hole regions of the N-type Ge layer by using an electron beam evaporation deposition process, as shown in FIG. 8 m.

Referring to fig. 9, fig. 9 is a schematic view of an LRC process according to an embodiment of the invention. The LRC process, namely the laser recrystallization process, is a thermotropic phase transition crystallization method, through laser heat treatment, the Ge epitaxial layer on the Si substrate is melted and recrystallized, the dislocation defect of the Ge epitaxial layer is released transversely, not only can the Ge epitaxial layer with high quality be obtained, meanwhile, because the LRC process can accurately control the crystallization area, on one hand, the problem of Si and Ge mutual expansion between the Si substrate and the Ge epitaxial layer in the conventional process is avoided, and on the other hand, the material interface characteristic between Si and Ge is good.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A light module, comprising:

the light emitting device is used for receiving the electric signal and generating an optical signal after processing, and the light receiving device is used for receiving the optical signal and outputting the electric signal after processing.

2. Optical module according TO claim 1, characterized in that the PIN detector (3) comprises an opto-electronic TO-CAN (31), a metal tube (32), a connection block (33) and an optical fiber (34) connected in sequence.

3. An optical module as claimed in claim 2, characterized in that the opto-electronic TO-CAN (31) comprises a tube cap (311) and a lens (312).

4. A light module as claimed in claim 3, characterized by further comprising an error detector (6) electrically connected to the signal output of the main amplifier (5) for detecting the error rate of the signal transmission.

5. The optical module of claim 4, further comprising a signal delay circuit (7), wherein the signal delay circuit (7) is electrically connected to a signal output of the main amplifier (5) and an input of the error detector (6) for delaying the electrical signal output by the main amplifier (5).

6. A light module as claimed in claim 5, characterized in that it further comprises a switch (8) connected in parallel with the signal delay circuit (7).

7. A light module as claimed in claim 6, characterized in that the infrared light source (1) comprises an infrared LED (10), a substrate (11), a lens (12), a gold wire (13) and a resin material (14); wherein,

8. The optical module according to claim 7, wherein the infrared LED (10) has an emission wavelength of 1550nm to 1650 nm.

9. A light module as claimed in claim 5, characterized in that the infrared LED (10) comprises: the semiconductor device comprises a substrate (101), a P-type crystallized Ge layer (102), an intrinsic Ge layer (103), an N-type Ge layer (104) and a passivation layer (105);

10. The light module according to claim 9, characterized in that the infrared LED (10) further comprises a positive electrode (106) and a negative electrode (107), the positive electrode (106) and the negative electrode (107) being connected to the P-type crystallized Ge layer (102) and the N-type Ge layer (104), respectively.