KR20180057014A - Optical receiving module - Google Patents

Abstract

The present invention relates to an optical reception module, which comprising: 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 portion installed in a receiving portion of the housing body, and converting the input optical signal into multi-channel branching light; a light receiving element including a first light receiving element or a second light receiving element for converting the multi-channel branching light into an electrical signal, wherein the first light receiving element and the second light receiving element are different in kind; and a feedthrough pattern portion including a first signal processing pattern portion for processing a first electrical signal from the first light receiving element and a power pattern portion provided adjacent to the signal processing pattern portion, wherein the power pattern portion serves as a second signal processing pattern portion for processing a second electrical signal from the second light receiving element. The present invention is able to improve productivity and economic efficiency by reducing design costs.

Description

[0001] OPTICAL RECEIVING MODULE [0002]

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

As the demand for data increases, the speed and capacity of optical communication have also been increasing rapidly. Optical communication systems having a transmission capacity of 10 Gbps or more have already been commercialized by using optical signals of a single wavelength. However, in recent metro and periodic transmission networks, a transmission capacity of 40 Gbps or 100 Gbps is required for one optical fiber, so that optical signals of four different wavelengths having a transmission rate of 10 Gbps or 25 Gbps are multiplexed on one optical fiber to transmit 40 Gbps or 100 Gbps (WDM) type optical communication for transmitting data is used.

In this wavelength division multiplexing optical communication, an optical transmission module for wavelength division multiplexing laser light of four wavelengths and an optical signal transmitted through an optical line are demultiplexed into respective wavelengths, "Wavelength Division Multiplexed Optical Receiving Module" which amplifies the detected electric signal is constituted as a core component of the optical communication system. The wavelength multiplexing light receiving module includes a receptacle for coupling an optical fiber connector and an optical receiving module located at the end of an optical line, an optical coupling lens, a demultiplexing device for demultiplexing received optical signals of different wavelengths into respective wavelengths, A photodetecting device for converting the lights separated into respective wavelengths into an electric signal (photocurrent), and a transfer-impedance-type amplifying device for amplifying these electric signals.

In such a wavelength multiplexed light receiving module, a photodetector element that converts an optical signal into an electric signal uses a photodiode (PD) or an APD (Alanche photo diode). In the case of using the photodiode and the case of using the APD, the configuration of the photodetecting device is different, and they must be separately designed.

In addition, since the optical alignment process is performed a plurality of times in the light receiving module, the manufacturing time and cost are increased.

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

[Department name] Future Creation Science & Industry Ministry of Commerce & Industry

[Research Project] Nano Fusion 2020 Project

[Project Title] 100Gbps Optical Receiver and Optical Transmitter Module Applying Ag-coated Cu Nanoparticle Material

[Research and Management Institution (Foundation) Nano Fusion 2020 Project Team

[Contribution rate] 100%.

[Main research institute]

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

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light receiving module in which different types of light receiving elements can be used.

According to an aspect of the present invention, there is provided a light receiving module including: a receptacle portion connected to an optical fiber connector having an optical fiber as a medium of an input optical signal; A housing main body having a receptacle connection portion connected to the receptacle portion; A filter unit installed in the receiving portion of the housing body to convert the input optical signal into multi-channel demultiplexed light; The light receiving element, the first light receiving element, and the second light receiving element each including a first light receiving element or a second light receiving element for converting the multi-channel demultiplexed light into an electric signal are different in kind; And a power supply pattern portion provided adjacent to the signal processing pattern portion for processing a first electrical signal from the first light receiving element, wherein the power supply pattern portion comprises: And a second signal processing pattern unit for processing the second electrical signal of the second signal processing unit.

The light receiving module may further include a ferrule installed inside the receptacle and aligning the optical fiber.

 The light receiving module may further include a lens installed on the receptacle connection portion concentrically with the upper device ferrule.

Here, the lens may be a spectroscopic lens.

The light receiving module may further include a metal optical bench mounted on a bottom surface of the housing main body.

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

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

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

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

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

Here, some of the ground pins may be formed in a "C" shape, and the power supply pin, the inner ground pin among the ground pins, the RSSI pin, and the external resistor pin may be located inside the power supply pin.

Here, the number of the RSSI pins and the number of the ground pins may be the same.

Here, the first light receiving element may be a pin photodiode, and the second light receiving element may be an APD.

Here, the APD is electrically connected to the ground pin of the power supply pattern part through wire bonding, so that the ground pin can operate as a signal pin.

Here, the filter unit may divide the input light into at least four multi-channel demultiplexed lights, and the first light receiving element or the second light receiving element may be composed of the same number of photodiodes as the number of the multi-channel demultiplexed light .

According to an embodiment of the present invention having the above-described configuration, it is possible to mass-produce a light receiving module having excellent compatibility with the types of light receiving elements, and to reduce the design cost, thereby improving productivity and economy.

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

1 is a sectional view of a light receiving module according to an embodiment of the present invention;
2 is an exploded perspective view of a light receiving module according to an embodiment of the present invention.
3 is a partially enlarged cross-sectional view illustrating an optical path in a light receiving module according to an embodiment of the present invention.
4 is a view for explaining an optical path in a filter part of a light receiving module according to an embodiment of the present invention.
5 is a view for explaining a feed-through pattern portion of a light receiving module according to 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 this specification, different embodiments are given the same reference numerals, and the description thereof is replaced with the first explanation.

1 and 2, a light receiving module according to an embodiment of the present invention includes a receptacle portion 1, a ferrule 11, a spectroscopic lens 22, a housing main body 2, a filter portion 3, An array lens 9, a light receiving element 4 including 41 to 44, an impedance amplifier 5, a feedthrough pattern 6, a metal optical bench 7, a mount 8, 83). ≪ / RTI >

The receptacle portion 1 is configured to be connected to an optical connector (not shown) located at the end of the optical path and including an optical fiber. And a cylindrical ferrule 11 for aligning the optical fiber is provided in the inside of the ferrule 11. The ferrule 11 is connected to a press-fit lens 22 (collimator lens) Immediate optical alignment is achieved.

The house body 2 has an overall shape of the light receiving module, and the material thereof is made of a metal material or a synthetic resin material. The house body 2 is provided with a receiving portion, and many parts to be described later are installed in the receiving portion.

A receptacle connection portion 21 to be fastened to the receptacle portion 1 is protruded from the house main body 2 and a spectroscopic lens 22 is installed on the receptacle connection portion 21. [ The spectroscopic lens 22 is installed coaxially with the ferrule 11 of the receptacle portion 1.

At the rear end of the spectroscopic lens 22, a filter unit 3 is formed. The filter unit 3 separates the optical signals received through the optical fiber into respective wavelengths and converts them into multi-channel optical signals. As shown in Figs. 1 and 2, the filter unit 3 includes a parallelogram type glass block 3-1 and a thin film filter (not shown) formed on one side of the glass block 3-1, And the coating portions 3-21 and 3-22 formed on the other side of the glass block 3-1. The filter unit 3 is formed by applying a whitish coating film 3-21 on a part of one side of a glass block 3-1 which is a glass plate having a predetermined refractive index and a thickness, 3-21) and then cut to a predetermined size. The cut glass block 3-1 is polished at a precise angle so that its cross section becomes a parallelogram shape, and then the thin film filters 31 to 34, And sequentially attaching the block 3-1 to a predetermined position on the other side corresponding to one side of the coating portion of the block 3-1. The demultiplexing of the light of the filter unit 3 will be described in more detail with reference to FIGS. 3 and 4. FIG.

The array lens 9 is formed by integrating lenses for converting divergent light into focal light into one component. In the case of the four-channel light receiving module as shown in the figure, four lenses or four lens regions are formed to form multi-channel demultiplexed light, respectively, through the filter portion 3, To focus light.

The light receiving element 4 is composed of photodiodes or APDs of the number of the demultiplexed lights and converts the respective demultiplexed lights into electric signals and then transmits the signals to the impedance amplifiers 5 located at the rear end.

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

The pin photodiode is an intrinsic semiconductor layer (i is intrinsic) inserted between a p-type semiconductor and an n-type semiconductor. Since the drift current is generated in the depletion layer, it responds rapidly in response to the influence of the electric field. Conversely, the diffusion current generated outside the depletion layer has a characteristic that the response speed is slow. The wider the depletion layer, And frequency response. Since 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, the i-type semiconductor bonded between the P-type and the N-type semiconductor functions to widen the width of the depletion layer .

The structure of the APD (avlanche photo diode) is almost the same as the PIN-PD. Here, the p-layer means a p-type semiconductor to which an acceptor is slightly added, and the p-layer means a high-resistance layer. In addition, in APD, a guide ring is set in order to generate a strong electric field by applying a high reverse bias to uniform the electric field to prevent damage to the device. A reverse bias of about 100 to 150 [V] higher than the PIN-PD is applied. The electric field is up to 105 [V / cm] in the vicinity of the high-resistance P layer. If light is incident on the n-layer, most of the voltage in the thick P- Absorbed, electrons and holes are generated, and the electrons enter the high electric field region beyond the slope of the energy. The electrons are accelerated by this strong electric field and collide violently with the electrons in the P layer or the P-layer, and the collided electrons protrude with energy and become a pair of electrons and holes newly. In addition, the electrons are accelerated and electrons and holes are increased in the strong field region, causing avalanche effect, and the photocurrent is multiplied. Therefore, in the PIN-PD, the occurrence of one electron can be amplified several times in the APD, so that the light with a small incident power can be detected, and the light receiving sensitivity is improved.

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

In the present invention, the number of light receiving elements is the same as the number of branched optical signals, and each branched optical signal 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 this impedance amplifier 5, an array preamplifier 5 in which transmission impedance type preamplifiers are integrated into one configuration can be used.

The metal optical bench 7 is provided on the bottom surface of the housing main body 2 and includes a filter portion 3, an array lens 9, a light receiving element 4, an impedance amplifier 5, and a feedthrough pattern portion 6 Are respectively seated and aligned and fixed, respectively. Concretely, an alignment groove corresponding to the glass block 3-1, the array lens 9 and the light receiving element 4 of the zigzag filter portion 3 can be formed on the upper side of the metal optical bench 7 have.

The feedthrough 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 unit 6 includes a signal processing pattern unit 61 and a power supply pattern unit 62. This configuration will be described with reference to FIG.

A mount for mounting the impedance amplifier 5 is formed around the impedance amplifier 5. The mount 8 includes a first submount 81 provided on the front end side of the impedance amplifier 5 and a second submount 82 and a third submount 82 provided on the side of the impedance amplifier 5 83). These mounts can be configured for signal transmission and power supply needs.

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

Referring to FIG. 4, the filter unit 3 (zigzag filter unit) is a demultiplexing device, which includes a glass block 3-1 having a parallelogram shape, And thin film filters 31 to 34 for passing the optical signal of the corresponding band. At this time, the coating portions 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 portions 3-21 and 3-22 are formed in the regions other than the regions where the anti-reflection coatings are formed and the anti-reflection coatings 3-21 formed in the regions corresponding to the regions where the optical signals are incident through the spectroscopic lenses, And a reflective coating 3-22 formed thereon. At this time, the anti-reflection film coating 3-21 formed on one side of the glass block 3-1 minimizes the loss due to reflection of the optical signal inputted through the spectroscopic lens 22 on the glass block 3-1 And the reflection coating 3-22 reflects the optical signal reflected from the first thin film filter 31 formed on the opposite side and is then reflected again and then incident on the second through fourth thin film filters 32-34 It plays a role.

FIG. 3 is a partially enlarged cross-sectional view for explaining an optical path in a light receiving module according to an embodiment of the present invention, and FIG. 4 is a view for explaining an optical path in a filter portion of a light receiving 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 spectral lens 22. These parallel lights are demultiplexed lights having different wavelengths through the filter portion 3 and the demultiplexed light is changed to focus light in the array lens 9 to form a light receiving element 4 (first to fourth light receiving elements 41 to 44), and the light receiving element 4 converts the demultiplexed light, which is the focus light, into an electric signal.

On the other hand, as shown in FIG. 4, the filter unit 3 includes thin film filters 31 to 34 that pass only respective wavelengths through a demultiplexing device for separating the wavelength of the multiplexed light into four wavelengths The optical signals (branched lights) of the respective wavelengths are reflected inside the zigzag filter, so that only the light of the transmission wavelength band defined by each thin film filter passes through the thin film filters 31 to 34 to generate the demultiplexed light .

Hereinafter, the feedthrough pattern portion 6 formed in the metal optical bench 7 will be described with reference to FIG.

5 is a view for explaining a feed-through pattern unit 6 in a light receiving module according to an embodiment of the present invention. The feed-through pattern unit 6 may include a signal processing pattern unit 61 and a power supply pattern unit 62. The signal processing pattern unit 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 unit 62 functions to supply power to the light receiving element. When the pin photodiode is provided, the power supply pattern portion 62 includes a power pin 622 that functions to input power to the pin photodiode simply, an outer ground pin 621 and an inner ground pin 621 ' An RSSI pin 623 for signal measurement at the pin photodiode, and an external resistor pin (R-Ext pin). When the 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 resistor pin 624 of the power supply pattern portion 62 function as signal pins . That is, when the APD is mounted, the APD connecting pin (not shown) in the light receiving element mounting module is connected to the inner ground pin 621 'of the power source pattern portion 62 and the external resistor pin 624 through wire bonding, The pin 621 'and the external resistor pin 624 each operate as the signal pin of each of the light receiving elements.

More specifically, as shown in FIG. 5, the ground pin 621 is formed to surround the outer circumference in the C shape. An inner ground pin 621 ', an RSSI pin 623, and an external resistor pin 624 are formed on the inside thereof. The example of FIG. 5 is a case in which the number of optical waveguides is four and the number of light receiving elements is four (first to fourth light receiving elements 411 to 44). The sum of the RSSI pins 623 is 4. The internal ground pin 621 'functions as a ground pin when a pin photodiode is provided but when the APD is attached, And the external resistor pin 624 functions as an external resistor pin when the pin photodiode is provided and the signal pin (of the first photodetector) when the APD is attached, The optical receiving module can be configured regardless of the type of the light receiving element.

According to an embodiment of the present invention having the above-described configuration, it is possible to mass-produce a light receiving module having excellent compatibility with the types of light receiving elements, and to reduce the design cost, thereby improving productivity and economy.

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

The light receiving module described above is not limited to the configuration and method of the embodiments described above, but the embodiments may be modified so that all or some of the embodiments are selectively combined so that various modifications can be made. Lt; / RTI >

1: receptacle portion
11: Ferrule
21: receptacle connection
22: (spectroscopic) lens
2: Housing body
3: (zigzag) filter part
31 to 34: First to fourth filters
4: Light receiving element
41 to 44: First to fourth light receiving elements
5: Impedance amplifier
6: Feedthrough pattern part
61: signal processing pattern section
62: Power supply pattern part
7: Metal optical bench
8: Mount
9: Array lens

Claims (15)

A receptacle portion connected to an optical fiber connector having an optical fiber as a medium of an input optical signal;
A housing main body having a receptacle connection portion connected to the receptacle portion;
A filter unit installed in the receiving portion of the housing body to convert the input optical signal into multi-channel demultiplexed light;
The light receiving element, the first light receiving element, and the second light receiving element each including a first light receiving element or a second light receiving element for converting the multi-channel demultiplexed light into an electric signal are different in kind; And
And a power supply pattern portion that is provided adjacent to the signal processing pattern portion, wherein the power supply pattern portion includes a first signal processing pattern portion for processing a first electrical signal from the first light receiving element, And serves as a second signal processing pattern section for processing the second electrical signal.
The method of claim 1, wherein
And a ferrule provided inside the receptacle portion for aligning the optical fiber.
3. The method of claim 2,
And a lens installed in the receptacle connection portion concentrically with the ferrule.
The method of claim 3,
Wherein the lens is a spectral lens.
The method according to claim 1,
And a metal optical bench mounted on a bottom surface of the housing main body.
6. The method of claim 5,
And an impedance amplifier provided at a front end of the feed-through pattern portion.
The method according to claim 6,
A mount mounted on the metal optical bench and configured for power supply to the light receiving element.
8. The method of claim 7,
The mount
A first submount disposed on a front end side of the impedance amplifier, a second submount disposed on a side of the impedance amplifier, and a third submount.
The method according to claim 1,
The power-
A power supply pin, an RSSI pin, a ground pin, and an external resistor pin.
10. The method of claim 9,
Wherein a part of the ground pin and the external resistor pin function as a signal pin when the second light receiving element is provided.
11. The method of claim 10,
A part of the ground pin
An outer ground pin formed in a "C" shape,
Wherein the power pin, the inner ground pin which is the remainder of the ground pin, and the RSSI pin are located inside the power pin.
12. The method of claim 11,
Wherein the number of the grounding pins, the number of the RSSI pins, and the number of the demultiplexing lights are the same.
The method according to claim 1,
Wherein the first light receiving element is a pin photodiode, and the second light receiving element is an APD.
14. The method of claim 13,
Wherein the APD is electrically connected to the ground pin of the power supply pattern portion through wire bonding, so that the ground pin operates as a signal pin.
The method according to claim 1,
The filter unit includes:
Demultiplexing the input light into at least four multi-channel demultiplexed lights,
The first light-receiving element or the second light-
And a number of photodiodes equal to the number of the multi-channel demultiplexed lights.

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