WO2018092950A1

WO2018092950A1 - Optical reception module

Info

Publication number: WO2018092950A1
Application number: PCT/KR2016/013357
Authority: WO
Inventors: 박준희; 박호산; 김동후; 전병중; 박진우
Original assignee: 주식회사 지피
Priority date: 2016-11-18
Filing date: 2016-11-18
Publication date: 2018-05-24

Abstract

The present invention relates to an optical reception module comprising: a receptacle connected to an optical fiber connector provided with optical fibers which are mediums for optical input signals; a housing main body provided with a receptacle connection part connected to the receptacle; a filter, disposed in an accommodation part of the housing main body, for converting an optical input signal into multi-channel branched beams; an optical reception element, comprising a first or second optical reception element, for converting the multi-channel branched beams into electrical signals, the first and second optical reception elements being optical reception elements of differing types; and a feed-through pattern unit comprising a first signal processing pattern unit for processing a first electrical signal from the first optical reception element, and a power pattern unit installed adjacent to the signal processing pattern unit, the power pattern unit acting as a second signal processing pattern unit for processing a second electrical signal from the second optical reception element.

Description

Optical Receive Module

The present invention relates to an optical receiving module capable of receiving an optical signal without being limited to the type of the light receiving element.

As the demand for data gradually increases, the speed and capacity of optical communication are also rapidly increasing. An optical communication system having a transmission capacity of 10 Gbps or more using a single wavelength optical signal has already been commercialized and used. However, in recent metro and periodic transmission networks, a transmission capacity of 40 Gbps or 100 Gbps is required for one strand of optical fiber, and multiplexed optical signals of four different wavelengths having a transmission rate of 10 Gbps or 25 Gbps in one optical fiber are used to multiplex 40 Gbps or 100 Gbps. Optical communication using a wavelength division multiplexing (WDM) method for transmitting data is used.

In the optical division of the wavelength division multiplexing method, the optical transmission module for wavelength division multiplexing the laser light of the four wavelengths and the optical signal transmitted through the optical path are demultiplexed into the respective wavelengths and detected by the optical detection element as an electrical signal. The “wavelength division multiplexed optical reception module”, which amplifies the detected electrical signals, constitutes the most essential component of the optical communication system. The wavelength multiplexing optical reception module is a demultiplexing element for demultiplexing optical signals of different wavelengths by receptacle, optical coupling lens, and optical fiber connector located at the end of the optical path. And a photodetecting device for converting light separated at each wavelength into an electrical signal (photocurrent), and an amplifying device of a transfer impedance type for amplifying these electrical signals.

In such a wavelength multiplexing optical reception module, a photodetector for converting an optical signal into an electrical signal uses a photodiode (PD) or an Alan photo diode (APD). In the case of using the photodiode and in the case of using the APD, the configuration of the photodetecting device will be different, and each of them must be designed separately.

In addition, the light receiving module has a problem that the manufacturing time and cost increase because the light alignment process is performed several times.

Accordingly, the present invention has been made as a result of the following research project.

[Department] Ministry of Science, ICT and Future Planning

[Research Project Name] Nano Convergence 2020 Project

[Project Name] 100Gbps Optical Receiver and Optical Transmitter Module Applying Cu Nanopowder Coated with Ag

[Research Management Agency 나 Nano Convergence 2020 Division

Contribution rate: 100%.

[Organized Research Institution] GPI

[Research Period] 2015.12. 01. ~ 2016. 11. 30.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a light receiving module that can be used for all of the different types of light receiving elements.

An optical reception module according to an embodiment of the present invention, which is designed to solve the above problems, includes a receptacle unit connected to an optical fiber connector having an optical fiber as a medium of an input optical signal; A housing body having a receptacle connection portion connected to the receptacle portion; A filter unit installed at a housing of the housing main body to convert the input light signal into multi-channel split light; The light-receiving element, the first light-receiving element, and the second light-receiving element, each of which includes a first light receiving element or a second light receiving element, respectively converting the multi-channel split light into electric signals; And a first signal processing pattern portion for processing the first electrical signal from the first light receiving element and a power supply pattern portion disposed adjacent to the signal processing pattern portion, wherein the power supply pattern portion is formed from the second light receiving element. May serve as a second signal processing pattern portion for processing a second electrical signal of;

Here, the light receiving module may further include a ferrule installed inside the receptacle to align the optical fiber.

The optical receiving module may further include a lens installed in the receptacle connecting portion concentrically with the ferrule.

Here, the lens may be a spectroscopic lens.

Here, the light receiving module may further include a metal optical bench installed on the bottom of the housing body.

Here, the light receiving module may further include an impedance amplifier installed at the front end of the feed-through pattern portion.

The light receiving module may further include a mount installed on the metal optical bench and configured to supply power to the light receiving device.

Here, the mount may include a first sub-mount installed in the front long side of the impedance amplifier, a second sub-mount and a third sub-mount installed in the side end of the impedance amplifier.

Here, the power pattern unit may include a power pin, an RSSI pin, a ground pin, and an external resistor pin.

Here, some of the ground pins and the external resistor pins may function as signal pins when the second light receiving element is installed.

Here, some of the ground pins are formed in a "c" shape, and the power pin, an inner ground pin, the RSSI pin, and the external resistance pin of the ground pin may be located inside the power pin.

The number of the RSSI pins may be the same as the number of the split light and the number of the ground pins.

Here, the first light receiving element may be a pin photo diode, and the second light receiving element may be APD.

Here, the APD is electrically connected to the ground pin of the power pattern part through wire bonding, and thus the ground pin may operate as a signal pin.

The filter unit may split the input light into at least four multi-channel split light, and the first or second light-receiving device may be configured with the same number of photodiodes as the number of multi-channel split light. Can be.

According to one embodiment of the present invention having the above-described configuration, by producing a light receiving module with excellent compatibility for the type of light receiving element, it is possible to mass production and to lower the design cost can increase productivity and economics.

In addition, according to one embodiment of the present invention, it is possible to improve the yield of the manufacturing process by providing a simple process with excellent light loss characteristics by improving the structure of the optical system for forming parallel light.

1 is a cross-sectional view of an optical receiving module according to an embodiment of the present invention.

Figure 2 is an exploded perspective view of an optical receiving module is an embodiment of the present invention.

Figure 3 is a partially enlarged cross-sectional view for explaining the optical path in the optical receiving module of an embodiment of the present invention.

4 is a view for explaining an optical path in the filter unit of the optical receiving module according to an embodiment of the present invention.

5 is a view for explaining the feed-through pattern portion of the optical receiving module is an embodiment of the present invention.

Hereinafter, a light receiving module according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, different embodiments are given the same reference numerals, and description thereof is replaced with the first description.

As shown in FIG. 1 and FIG. 2, the light receiving module according to the embodiment of the present invention includes a receptacle unit 1, a ferrule 11, a spectroscopic lens 22, a housing body 2, and a filter unit 3. Array lens 9, light receiving elements (including 4:41 to 44), impedance amplifier 5, feedthrough pattern portion 6: feedthrough pattern, metal optical bench 7, mounts 8: 81 to And 83).

The receptacle part 1 is a structure for connecting with the optical connector (not shown) which is located in the optical fiber terminal and contains an optical fiber. The inside of the cylindrical ferrule 11 is arranged to align the optical fiber, the ferrule 11 is coaxially connected to the indented lens 22 (collimator lense) described later to fasten without a separate optical alignment process Light alignment is achieved immediately.

The house body 2 has the overall shape of the light receiving module, and the material is made of metal or synthetic resin. The house main body 2 is provided with a receiving part, and many parts mentioned later will be installed in this receiving part.

The receptacle connecting portion 21, which is fastened to the receptacle portion 1, protrudes from the house body 2, and the spectroscopic lens 22 is installed in the receptacle connecting portion 21. This spectroscopic lens 22 is provided coaxially with the ferrule 11 of the receptacle portion 1.

The filter part 3 is formed in the rear end of the spectroscopic lens 22. The filter unit 3 functions to separate the optical signal received through the optical fiber for each wavelength and convert it into multi-channel split light. As shown in FIGS. 1 and 2, the filter unit 3 is formed on a parallelogram-type glass block 3-1 and on one side of the glass block 3-1 and is a thin film filter that transmits the divided light, respectively. Fields 31 to 34, which are equal to the number of split lights, and coating portions 3-21 and 3-22 formed on the other side of the glass block 3-1. The filter unit 3 is first applied to the non-film coating (3-21) of a portion of one side of the glass block (3-1), which is a glass plate having a predetermined refractive index and thickness, and a reflective film coating ( 3-21), cut out to have a predetermined size, and then polish the cut glass block 3-1 at a precise angle so that its cross section is in the form of a parallelogram, and then pre-fabricate the thin film filters 31 to 34. The coating part of the block 3-1 may be manufactured through a process of sequentially attaching the coating part to a predetermined position on the other side surface corresponding to the one side surface. The branching of the light of the filter unit 3 will be described in more detail with reference to FIGS. 3 and 4.

The array lens 9 integrates a lens for converting divergent light into focus light into one component. That is, for the four-channel optical receiving module, as shown in the figure, for making the multi-channel split light through the filter unit 3 as the focused light, respectively, four lenses or four lens regions are formed, respectively. It converts the light into focus light.

The light receiving element 4 is composed of as many photodiodes or APDs as the number of branched light, and converts each branched light into an electric signal, and then transmits the signal to the impedance amplifier 5 located at the rear end.

The light receiving element 4 can be roughly divided into a pin photodiode (or Pin-PD) and an APD (Alanche Photo diode). In the case of the optical reception module according to the present invention, both the pin-PD is mounted or the APD is operated. This will be described later.

In the pin photodiode, an intrinsic semiconductor i layer (i is an intrinsic) is inserted between a P-type semiconductor and an N-type semiconductor. Since the drift current is made in the depletion layer, it responds quickly according to the influence of the electric field. On the contrary, the diffusion current made outside the depletion layer has a slow response time. The wider the depletion layer, the wider the quantum efficiency. It is advantageous in terms of over frequency response speed. The width of the depletion layer becomes wider as the concentration of electrons and holes in the P-type and N-type semiconductor layers becomes lower, so that the i-type semiconductor bonded between the P-type and N-type semiconductors plays a role in widening the width of the depletion layer. .

The structure of APD (APD; avlanche photo diode) is almost the same as that of PIN-PD. Here, the p-layer is a P-type semiconductor with a small amount of acceptor, and the P layer is a high resistance layer. In the APD, a high reverse bias is applied to generate a strong electric field, so that a guide ring is set to prevent damage to the device by making the electric field uniform. Apply a reverse bias of 100 to 150 [V] higher than that of the PIN-PD. Most of this voltage is applied to the P- and P layers, but especially near the high-resistance P layer, the electric field is up to 105 [V / cm]. As it is absorbed, pairs of electrons and holes are created and electrons enter the high field region beyond the slope of energy. The electrons are accelerated by the strong electric field and collide violently with the electrons of the P layer or the P-layer, and the collided electrons get energy and bounce off to form a new pair of electrons and holes. In addition, the electrons are accelerated to increase the electrons and holes in the strong electric field, causing an avalanche effect and increasing the photocurrent. Therefore, since the generation of one electron in the PIN-PD can be amplified several times in the APD, light having a small incident power can be detected, thereby improving the light receiving sensitivity.

In the present invention, a pin photodiode or APD may be used as the light receiving element in some cases. That is, the signal processing pattern portion 61 of the feedthrough pattern portion 6 to be described later is for processing the signal of the pin photodiode, and the power supply pattern portion 62 is a part of the ground pin when APD is used. The role is changed to process the APD signal. That is, some of the ground pins are connected to the APD by wire bonding.

In the present invention, the light-receiving element is composed of the same number as the number of divided light, so that each of the divided light is converted into an electrical signal.

The impedance amplifier 5 is provided at the rear end of the light receiving element 4, and functions to amplify the electric signal converted by the light receiving element. As such an impedance amplifier 5, an array preamplifier 5 in which transfer amplifier type preamplification elements are integrated into one configuration can be used.

The metal optical bench 7 is installed at the bottom of the housing main body 2, and includes a filter unit 3, an array lens 9, a light receiving element 4, an impedance amplifier 5, and a feedthrough pattern unit 6 described later. The mounting portions may be each formed to be machined so that they may be seated and aligned and fixed, respectively. Specifically, an alignment groove of a shape corresponding to the glass block 3-1, the array lens 9, and the light receiving element 4 of the zigzag filter unit 3 may be formed on the upper side of the metal optical bench 7. have.

The feed-through pattern portion 6 is formed on the metal optical bench 7 on the rear end side of the impedance amplifier 5. The feed-through pattern section 6 is composed of a signal processing pattern section 61 and a power supply pattern section 62. This configuration will be described with reference to FIG. 5.

The mount for installing the impedance amplifier 5 is formed around the impedance amplifier 5. The mount 8 includes a first sub-mount 81 provided at the front end side of the impedance amplifier 5, a second sub-mount 82 and a third sub-mount provided at the side ends of the impedance amplifier 5 ( 83). Such a mount may be configured by the need for signal transmission and power supply.

Hereinafter, a propagation process and a conversion process of an optical signal will be described with reference to FIGS. 3 and 4.

Referring to FIG. 4, the filter unit 3: the zigzag filter unit is a demultiplexing element, and the glass block 3-1 and the one side of the glass block 3-1 in parallelogram shape are spaced at regular intervals. It may be formed to include a thin film filters 31 to 34 to pass through the optical signal of the corresponding band. In this case, the coating parts 3-21 and 3-22 may be formed on the other side of the glass block 3-1 on which the thin film filters 31 to 34 are formed. The coating parts 3-21 and 3-22 are applied to the remaining areas except for the anti-reflective coating (3-21) and the non-reflective coating, which are formed in a predetermined area corresponding to the area where the optical signal is incident through the spectroscopic lens. It may be formed by dividing the reflective film coating (3-22) to be formed. At this time, the anti-reflective coating (3-21) formed on one side of the glass block (3-1) minimizes the loss due to the reflection of the optical signal incident through the spectroscopic lens 22 to the glass block (3-1) And the reflective film coating 3-22 causes the optical signal returned from the first thin film filter 31 formed on the opposite side to be reflected again and then incident to the second to fourth thin film filters 32 to 34. Play a role.

3 is a partially enlarged cross-sectional view for describing an optical path in an optical reception module according to an embodiment of the present invention, and FIG. 4 is a view for explaining an optical path in a filter unit of an optical reception module according to an embodiment of the present invention. As shown in Figs. 3 and 4, first, the optical signal aligned in the ferrule 11 is converted into parallel light by the spectroscopic lens 22. As shown in Figs. The parallel light becomes divided light having different wavelengths through the filter portion 3, and the divided light is changed into focus light in the array lens 9, so that the light receiving elements 4: the first to fourth light receiving elements ( 41 to 44), and the light receiving element 4 converts the branched light, which is this focused light, into an electric signal.

Meanwhile, as shown in FIG. 4, the filter unit 3 includes thin film filters 31 to 34 that pass only respective wavelengths as demultiplexing elements for separating the multiplexed light wavelengths into four wavelengths. As the optical signals (split light) of each wavelength are reflected inside the zig-zag filter, only the light of the wavelength band defined by each thin film filter passes through the thin film filters 31 to 34 to generate the split light. Done.

Hereinafter, the feedthrough pattern part 6 formed on the metal optical bench 7 will be described with reference to FIG. 5.

5 is a view for explaining the feed-through pattern unit 6 of the light receiving module according to an embodiment of the present invention. The feedthrough pattern part 6 may include a signal processing pattern part 61 and a power supply pattern part 62. The signal processing pattern portion 61 functions to connect the signal to the subsequent substrate S when a pin photodiode (first light receiving element) is provided. The power supply pattern portion 62 functions to supply power to the light receiving element. When the pin photo diode is installed, the power supply pattern unit 62 has a power pin 622, an outer ground pin 621 and an inner ground pin 621 ', each of which simply inputs power to the pin photo diode. It functions as RSSI pin 623 and external resistance pin (R-Ext pin) for signal measurement in pin photodiode. By the way, when APD (second light receiving element 4) is provided as the light receiving element of the light receiving module, the inner ground pin 621 'and the external resistance pin 624 of the power supply pattern portion 62 function as signal pins. Will be That is, when the APD is mounted, the APD connection pin (not shown) in the light receiving element mounting module is connected to the inner ground pin 621 ′ and the external resistance pin 624 of the power supply pattern 62 through wire bonding to thereby ground the inner portion. Each of the pin 621 ′ and the external resistor pin 624 acts as a signal pin of each of the light receiving elements.

In more detail, as shown in FIG. 5, the ground pin 621 is formed to surround the outside in a U shape. Inside thereof, an inner ground pin 621 ′, an RSSI pin 623, and an external resistance pin 624 are formed. 5 illustrates a case where the number of the divided light beams is 4, so that the light receiving elements are four (first to fourth light receiving elements 411 to 44. Accordingly, the inner ground pins 621 'and the external resistance pins 624 are formed. The sum is 4 and the number of RSSI pins 623 is 4. Here, the inner ground pins 621 'function as ground pins when a pin photo diode is installed, but if APD is attached, they are signal pins ( Second to fourth light-receiving elements), and the external resistance pin 624 functions as an external resistance pin when a pin photodiode is installed, and a signal pin (of the first light-receiving element) when APD is attached. In this way, the optical receiving module can be configured regardless of the type of the light receiving element.

The optical reception module described above is not limited to the configuration and method of the embodiments described above, but the embodiments may be selectively combined with all or some of the embodiments so that various modifications can be made. Can be configured.

Claims

A receptacle portion connected to an optical fiber connector having an optical fiber as a medium of an input optical signal;

A housing body having a receptacle connection portion connected to the receptacle portion;

A filter unit installed at a housing of the housing main body to convert the input light signal into multi-channel split light;

The light-receiving element, the first light-receiving element, and the second light-receiving element, each of which includes a first light receiving element or a second light receiving element, respectively converting the multi-channel split light into electric signals; And

A feed-through pattern portion including a first signal processing pattern portion for processing the first electrical signal from the first light receiving element and a power supply pattern portion disposed adjacent to the signal processing pattern portion, the power supply pattern portion from the second light receiving element And acting as a second signal processing pattern portion for processing the second electrical signal.
The method of claim 1

And a ferrule installed inside the receptacle to align the optical fiber.
The method of claim 2,

And a lens installed in the receptacle connecting portion concentrically with the ferrule.
The method of claim 3, wherein

The lens is a light receiving module, the spectroscopic lens.
The method of claim 1,

And a metal optical bench installed at the bottom of the housing body.
The method of claim 5, wherein

And an impedance amplifier installed in front of the feed-through pattern portion.
The method of claim 6,

And a mount mounted on the metal optical bench, the mount configured to supply power to the light receiving element.
The method of claim 7, wherein

The mount is,

And a second sub-mount installed at a front end side of the impedance amplifier, a second sub-mount mounted at a side end of the impedance amplifier, and a third sub-mount.
The method of claim 1,

The power supply pattern unit,

A light receiving module comprising a power pin, RSSI pin, ground pin, and external resistor pin.
The method of claim 9,

Some of the ground pins and the external resistance pins function as signal pins when the second light receiving element is installed.
The method of claim 10,

Some of the ground pins,

The outer ground pin is formed in the "c" shape,

The power pin, the inner ground pin that is the remainder of the ground pin, the RSSI pin is located inside the power pin, the optical receiving module.
The method of claim 11,

And the number of ground pins, the number of RSSI pins, and the number of split light are the same.
The method of claim 1,

The first light receiving element is a pin photo diode, and the second light receiving element is an APD.
The method of claim 13,

The APD is electrically connected to the ground pin of the power pattern portion through wire bonding, and thus the ground pin operates as a signal pin.
The method of claim 1,

The filter unit,

Split the input light into at least four multi-channel split light,

The first light receiving element or the second light receiving element,

And a photodiode of the same number as the number of the multi-channel split light.