KR20170060839A

KR20170060839A - optical engine

Info

Publication number: KR20170060839A
Application number: KR1020150165548A
Authority: KR
Inventors: 이은구; 이상수; 이정찬
Original assignee: 주식회사 옵텔라
Priority date: 2015-11-25
Filing date: 2015-11-25
Publication date: 2017-06-02
Also published as: KR101769034B1

Abstract

An optical device circuit device mounted on an upper surface of the mount and having at least one of a plurality of optical device arrays, a drive driver for driving the optical device, and a processing device for processing a signal by light received by the optical device; And a spacer provided above the optical element for securing a space for an optical interface in the periphery of the optical element. The optical element includes a stem forming an electrical interface with an external circuit, And a cover block for receiving the light from the light source and outputting the light to the side surface or receiving light from the side surface and outputting the light to the side surface. In the cover block, the number of the optical guide layers corresponding to the number of the optical element rows And the optical guide layer corresponding to the optical element row is formed in a multi- Reflects the light of the optical device and transmits the light along the optical guide layer laterally or reflects the light transmitted to the side along the optical guide layer and transmits the reflected light to the optical device The optical engine is characterized in that
According to the present invention, it is possible to provide an optical engine having a structure in which a plurality of rows of optical elements can be installed on one stem and a coupling between the optical element and the optical guide can be accurately and easily performed even when a plurality of optical elements are installed have.

Description

Optical engine

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication device, and more particularly, to an optical communication device capable of increasing the degree of integration of an optical device that can be used for optical communication and capable of increasing communication traffic capacity and simplifying coupling between an optical device and a light guide will be.

Increasing capacity of content based on large-capacity contents, rapid increase of penetration rate of smartphone, and rapid increase of data center have been continuously researched. To solve this problem, the International Organization for Standardization (IETF) has published a standard using the same wavelength multi-channel technology and wavelength division multiplexing technology, and many organizations and researchers are studying how to implement these technologies. These standards and technologies must address cost reduction, speed, miniaturization and low power issues, and laser array based optical transmitters have been developed and used in practical applications as a solution to the optical transceiver component of the network.

In order to increase the optical coupling efficiency between the laser and the optical waveguide in the optical transmitter, a lens is generally used. Lenses can be used to implement optical coupling, which can increase optical coupling efficiency, increase tolerance, or optimize the package structure at an appropriate level between the two, depending on the characteristics of the system. However, when the distance between the laser and the laser is set to 250 μm for optical coupling with the conventional optical fiber array and optical waveguide array, a lens used for optical coupling must be formed into an array shape, which causes a disadvantage that the cost increases. If the pitch of the laser is increased in order to reduce the manufacturing cost of the lens array, the number of lasers that can be manufactured in one wafer decreases, which causes an increase in the price of the laser.

The conventional optical engine uses a 45-degree mirror, so the distance between the light source (or photodetector) and the optical waveguide (optical fiber) is too long to use two lenses or one lens. In this case, since many mechanisms such as a guide post, a latch, and the like are inserted for optical coupling, a complicated structure and a packaging process become difficult. In addition, most conventional optical engines use optical waveguide arrays that do not use optical multiplexers (wide-area multiplexers), making them unsuitable for use in multi-wavelength systems.

When a plurality of lasers are formed on one chip, it becomes difficult to use them in a standard using four wavelengths, such as 40G BASE-LR4 or 100G BASE-LR4. The reason why it is difficult to make different wavelengths when a plurality of lasers are formed on one chip is as follows. First, since a large number of lasers use the same active layer, a wide gain curve must be obtained. Second, the oscillation wavelength varies depending on the length of the resonator. If a plurality of lasers are formed on one chip, it is difficult to make the length of the resonator different. Although it is possible to make the laser operate in a relatively wide range on a single chip, there is a disadvantage that the manufacturing cost is increased, so that it is difficult to cope with the increase of the current traffic.

In order to output different wavelengths, a method of implementing a laser array by mounting independent single lasers on one mount may be used. In this case, the distance between the lasers can be widened without decreasing the number of lasers per wafer, and the interval between the lens arrays can be widened, so that it is possible to use a low cost lens array having a relatively long distance between the lenses. However, despite the use of low cost lens arrays, the use of conventional packaging methods still has disadvantages in terms of components used in the package, packaging time and packaging cost.

For example, in the case of a high-speed optical transmitter, a mini DIL package using a ceramic-feedthrough is used to ensure a high-speed electrical interface and high reliability. The cost of the optical subassembly (OSA: optic subassembly) increases because of the high cost and the work in a narrow space inside the case.

The fundamental reason for such a problem is that the optical transceiver that connects the physical layer due to the rapidly increasing data traffic requires high performance in terms of operation, while the size of the components constituting the network must be reduced in terms of management, This is due to the contradictory situation that prices should be lowered.

In order to solve the problems and contradictions of the prior art, there is a need for an optical module having high performance, low cost, low power and small size.

Particularly, in the case where a plurality of optical elements of different types such as a light source and a photodetector are formed in a single optical engine at a high degree of integration, compared to the case of dividing such structures and combining them to form an overall optical communication device, And the optical coupling efficiency can be improved. However, considering the internal structure such as the stem of the optical engine and the optical coupling portion of the conventional optical engine, and the coupling type, it is difficult to form such an optical engine It will be a very difficult task, and the cost can be very high.

U.S. Patent Application Publication No. 2004/0264884: compact package design for vertical cavity surface emitting laser array to optical fiber cable connection. U.S. Patent Application Publication No. 2006/0162104: High speed optical sub-assembly with ceramic carrier.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described problems of the conventional optical engine, and it is an object of the present invention to provide an optical device having a plurality of optical elements arranged in a single stem, And an object of the present invention is to provide an optical engine having a configuration that can be easily and easily achieved.

The present invention is capable of forming a plurality of optical element rows of different kinds in one stem and precisely and easily combining the optical element and the optical guide even when the multiple optical element rows are provided RTI ID = 0.0 > optical < / RTI >

The present invention relates to a method of fabricating an optical communication device such as an optical transceiver such as an optical transceiver with low cost and high performance by reducing the cost of manufacturing and packaging by increasing the spatial efficiency and optical coupling efficiency of the device configuration by connecting the light source and the light receiving device together at adjacent distances And to provide an optical engine that enables the light source to emit light.

According to an aspect of the present invention,

An optical device circuit device mounted on the upper surface of the mount and having at least one of a plurality of optical element arrays, a driving driver for driving the optical element, and a processing device for processing a signal by the light received by the optical device; A stem provided at an outer periphery of the optical device at a mount, the spacer being provided above the optical device so as to secure a space for an optical interface above the optical device, and having an electrical interface with an external circuit;

And a cover block which receives the light from the light source and outputs the light to the side surface or receives light from the side surface and outputs the light to the bottom surface,

The cover block is provided with a plurality of optical guide layers having a different number of optical guide layers corresponding to the numbers of the optical element rows, and the optical guide layer corresponding to the optical element columns has an end portion on the upper side of the optical element So that the light reflected by the optical device is transmitted laterally along the optical guide layer or reflected by the optical guide layer and reflected by the optical guide layer to be transmitted to the optical device.

In the present invention, the cover block may be provided with an optical coupling port or other device on a side of the cover block that forms an optical interface with the outside of the cover block to serve as an optical coupling part.

In the present invention, optical fibers corresponding to the individual optical elements constituting the optical element array may be arranged side by side on the same plane, and the mirror constituting the inclined surface may be formed at each end of the individual optical fibers.

In the present invention, the optical guide layer is composed of one light guide plate layer, and the mirror constituting the inclined surface may be common to all the individual optical elements constituting the optical element array through the entire one end surface of the light guide plate. The optical multiplexer may further include an arrayed waveguide grating (AWG), a waveguide grating (AWG), and a waveguide grating (AWG) And at least one element of a thin film filter (TFF). In this state, a side end constituting the optical interface of the cover block may form an optical coupling port or other device with the outside.

In the present invention, the distance between the rows of optical elements may be equal to the height difference between the optical guide layers and the inclination angle of the inclined surfaces may be 45 degrees. At this time, the inclined surface constituting the mirror of the end portion of the upper optical guide layer and the inclined surface constituting the mirror of the end portion of the lower optical guide layer exist in one inclined plane, and the side end face of the entire cover block may be processed into a single inclined plane .

In the present invention, the distance between the optical element rows is different from the height difference between the optical guide layers, and the inclined surface constituting the mirror of the end portion of the optical guide layer and the inclined surface constituting the mirror of the end portion of the optical guide layer of the lower portion, And may be formed so as to form a step at a side cross-sectional view of the entire cover block.

In the present invention, an electrical pad for electrical interfacing with the exterior of the stem may be formed on the mount side, or may be formed on the mount bottom by a via through the mount.

In the present invention, the spacer is formed to form a closed curve on the four sides around the optical element, and the cover block including the optical guide layer is coupled with the spacer to seal a part of the plane surrounded by the closed curve, An auxiliary cover may be provided which is coupled with the spacer to be sealed therethrough.

At this time, the lower surface of the cover block and the auxiliary cover may be such that the size and the shape of the cover are at least partially matched with the spacer so that the inclined mirror surface of the optical element and the light guide are opposed to each other at the closest position. May be first integrally a-coupled, and in that state, may be sealingly coupled such that the spacer and outer angle are matched.

In the optical engine of the present invention, the light source may be a laser diode (LD), the light receiving element may be a photodetector (PD), the driver for driving each optical element may be a laser diode driver, TIA: trans-impedance amplifier), and the optical device-related circuit device may be integrally formed by including a laser diode driving driver and ATI, or may be formed by separately forming a driving driver chip and an AIT chip, It is possible.

In the optical engine of the present invention, the mount may be a flexible printed circuit board (FPCB), and may be a box integrally formed with the spacer and having a closed face of the hexahedron.

In the present invention, a high reflection layer (HR coating) for enhancing the reflection efficiency may be provided on the inclined mirror surface of the end portion of the optical guide layer, and the light distribution with the optical element may be provided on the lower surface of the cover block below the inclined mirror surface It is preferable that an AR coating is provided so that it can be well formed.

In the present invention, the material between the light guide layers constituting the cover block is a transparent material that allows light to pass therethrough and is made of a material having a lower refractive index than that of the light guide plate or optical fiber so that the light guide plate or the optical fiber .

According to the present invention, it is possible to provide an optical engine having a structure in which a plurality of rows of optical elements can be installed on one stem and a coupling between the optical element and the optical guide can be accurately and easily performed even when a plurality of optical elements are installed have.

The present invention can provide an optical engine in which a plurality of heterogeneous optical elements are installed in one stem, and the coupling between the elements and the optical guide can be accurately and easily performed. In particular, It is possible to provide an optical engine having a configuration capable of simply and accurately associating a light guide train for each optical element row.

Accordingly, the present invention can improve the spatial efficiency and optical coupling efficiency of a device configuration by connecting a light source and a light receiving device together at adjacent distances, and it is possible to reduce the cost of manufacturing and packaging and to provide an optical communication device such as an optical transceiver, It is possible to provide an optical engine that makes it possible to fabricate an optical system.

1 is a perspective view showing an optical engine according to an embodiment of the present invention,
FIG. 2 is a perspective oblique view showing an optical coupling part of an optical fiber constituting an optical device and a light guide in an embodiment of the present invention,
Fig. 3 is a cross-sectional view showing one section of the optical fiber cut perpendicularly to the portion of Fig. 2,
4 is a cross-sectional view showing a cross-section of an embodiment other than that of Fig. 3,
5 is a perspective view showing another embodiment showing a state in which the optical element installation space of the stem is sealed by adding an auxiliary cover.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 to 3, the optical engine includes a stem 10 and a cover block 20 (cover 1).

In this case, the stem 10 is formed with a square spacer 15 in the form of a sidewall protruding upward in the periphery of the upper surface of the mount 11, which is a rectangular flat plate, and has a substantially frame-like shape, An optical element array 12a in which the laser diodes are arranged in a row and an optical element array 12b in which the individual optical detectors are arranged in a row are arranged parallel to each other, A chip 13a and a transimpedance amplifier (TIA) chip 13b for processing a signal of the photodetector are provided.

Here, the optical device-related circuit devices are separately provided from the laser diode driver chip and the ATI chip, but they may be integrally formed, and the optical device may also be formed of only one kind of light source or photodetector.

Around the chip, there is provided an electric pad for receiving an external signal, which is connected to the electric pads 17 formed on the sidewall of the mount 11 through the built-in lead of the mount. The electrical pad 17 formed on the mount side wall forms an electrical interface with an external circuit (circuit board).

The cover block 20 is placed on the spacer 15 to form a connection surface with the stem. Light from an individual light source of the optical element array 12a, which is a light source, And outputs it to the lower surface of the optical element array 12b made up of the photodetector.

In the cover block, two optical guide layers 21 and 23 corresponding to two optical device columns 12a and 12b made up of a light source array and a photodetector array are provided in a plurality of layers with different heights from each other, The guide layer has a mirror having an inclined surface at an upper portion of an individual optical element forming an optical element array so as to reflect the light of the individual optical element and transfer the light to the side along the optical guide layer 21, And transmits the reflected light to the optical device.

In the present embodiment, the optical guide layers 21 and 23 are formed such that optical fibers corresponding to the individual optical elements constituting the optical device columns 12a and 12b are arranged side by side on the same plane, Each end of the individual optical fiber is installed.

In this embodiment, the light guide layers are made of optical fiber arrays arranged side by side. However, according to the embodiment, the light guide layer is composed of a light guide plate layer which is one flat plate, and the mirror constituting the inclined plane forms a slope at one side end face of the light guide plate, And may be a common mirror that reflects light from all of the individual optical elements that make up the array of optical elements.

The use of such a light guide plate may further include an optical multiplexing device (not shown) for multiplexing wavelengths while receiving light from the side of each light guide plate layer on the side of the optical interface with the outside, so that it can be used to increase the traffic capacity in the optical communication. The optical multiplexing device may be fabricated in the form of a sub-block or, in terms of functionality, multiplexes optical signals of different wavelengths, demultiplexes multiplexed optical signals, or transmits multi-channels of different paths to a photodetector (PD) (MUX / DEMUX) such as a combination of an AWG or a thin film filter (TFF) as an optical multiplexing device. In this state, a side end constituting the optical interface of the cover block is not shown but may form an optical coupling port or other device with the outside.

The shape of the optical input / output unit forming the optical interface with the cover block may vary depending on whether the optical multiplexing apparatus is coupled or not. The optical input / output unit may include an optical fiber block and an optical fiber pigtail, and the optical interface with the outside may be in the form of an optical receptacle or an optical patch cord. At this time, the surface to be bonded to the light guide plate block can be improved in optical performance by using an angled facet, using an AR coating, or both, to reduce the influence of reflection.

The number of connection ports can be configured as a single port when the light guide plate block includes multiplexing and demultiplexing elements. In the case of a simple light guide, a plurality of ports are arrayed, so that the same number of ports as the light guide plate block . For example, if the light guide plate block multiplexes four wavelengths of different wavelengths and outputs the light to one port, the light input / output unit also has one port, and the light guide plate block has four channels (in this case, When outputting, the optical input / output unit also has four connection ports.

The optical input / output unit may include various types of known optical units such as a fiber ferrule, a fiber ferrule including a fiber block, a fiber block and a patch cord, Or a receptacle may be mixed and receptacle type.

3, the distance between the two optical device columns 12a and 12b is different from the height difference between the two optical guide layers 21 and 23, 23a and the mirror 21a at the end of the lower optical guide layer do not exist in one inclined plane and the step (mirror surface 1, 2 interval) in the side view of the whole of the cover block 20, Respectively.

Preferably, however, the distance between the two optical element rows 12a and 12b 'is equal to the difference in height between the light guide layers, and the inclination angle of the inclined surface forming the entire end of the cover block is 45 degrees. At this time, the inclined surface constituting the mirror 23a at the end portion of the upper light guide layer 23 and the inclined surface constituting the mirror 21a at the end portion of the lower light guide layer 21 are present in one inclined plane, The side cross-section may be machined into a single inclined plane.

This embodiment can also be seen in the sectional view of FIG.

In this embodiment, the inclined surface constituting the mirror of the end portion of the upper optical guide layer and the inclined surface constituting the mirror of the end portion of the lower optical guide layer are present in one inclined plane. This can be produced by processing the entire side surface of the cover block into a single inclined plane and forming a highly reflective film (HR coating) 25 having a high reflectance on the machined surface of the inclined surface.

On the other hand, the auxiliary material layer under the optical guide layer and the auxiliary material layer between the optical guide layers, which form a path for transmitting or receiving light between the optical device and the mirror, are transparent materials that allow light to pass therethrough, (Core) so that the light is totally reflected at the boundary between the light guide plate and the optical fiber (core).

Optical fiber mounting grooves are formed in parallel to each other in the auxiliary material layer in order to form the optical guide layer with the optical fiber column, and the optical fibers can be fixed by using this groove.

In order to reduce the light loss, the antireflection film may be formed as a whole on the bottom surface of the cover block where the light is incident on the cover block, An anti-reflection film (AR coating) 27 is preferably provided.

5 is a perspective view showing another embodiment showing a state in which an optical element installation space of a stem is sealed by adding an auxiliary cover as compared with the embodiment of FIG.

In the present embodiment, the quadrangular spacer forming the upper end of the stem is formed so as to form a closed curve on the four sides of the periphery of the optical element when viewed from above, and the cover block including the plurality of optical guide layers, Lt; / RTI >

At this time, the lower surface of the cover block 20 is matched in size and shape with the spacer so that the optical element and the tilted mirror surface of the light guide face each other at the closest position. In this case, the optical engine is assembled by combining the stem and the cover block The packaging can be made easily and inexpensively.

In the present embodiment, the auxiliary cover 30 is provided in addition to the cover block 20, and the auxiliary cover 30 serves to cover and seal the remaining part of the plane surrounded by the spacer . The auxiliary cover may also serve to assist the optical element and the light guide so that the tilted mirror surface of the optical element is opposed to the closest position at the position where the portion contacting the spacer and the portion contacting the cover block are matched with each other.

The auxiliary cover may be first integrally coupled with the cover block, and in this state, may be sealingly coupled with the spacer to match the outer angle. If the sealing is performed well, the inflow of external air and moisture into the space surrounding the optical element can be suppressed and prevented, and the lifetime of the optical element can be relatively increased. To accomplish this, the cover block, the auxiliary cover, and the spacer are brought into close contact with each other by a sealant or an adhesive having good sealing force in a state of matching. Materials such as metals, ceramics, glass, and silicones may be used for strong bonding and hermetic sealing.

In the present invention, the electrical pad for electrical interfacing with the outside of the stem may be formed on the mount side as shown in FIG. 1, etc., or may be formed on the mount side by a via through the mount.

The electrical interface can consist of high speed signal lines that carry signals and control lines that monitor the performance and control of the laser diode or photodetector. At this time, the electrical interface may be formed using a conductive pattern or via, or a lead pin, which may also vary depending on the material used to fabricate the mount or the function of the mount.

A top pad for mounting a driver chip or ATI chip and a top pad for mounting an optical device may be provided and the top pad may be connected to the bottom of the stem via a via. This is for discharging the generated heat to the outside using the vias and the floor.

If the material of the mount is mainly made of synthetic resin, the vias are preferable, but if the material of the mount is made of a metal, a ceramic or a silicon material, its thermal conductivity is good. Therefore, it is preferable not to use vias in terms of ease of manufacture and cost can do.

The mount may be, for example, a flexible printed circuit board (FPCB), and may be a box integrally formed with the spacer such that the face of the hexahedron is closed. If an electrical element is attached to the mount, an electrical circuit may be constructed on the mount. For example, an electrical filter can be installed to eliminate noise in the power signal injected into the electrical device. Alternatively, a circuit such as an impedance matching circuit can be configured to adjust the signal level.

As a light source, it is preferable that a laser diode of a vertical cavity surface emitting laser (VCSEL) type having a low degree of divergence according to progress is used as a laser diode in order to increase light transmission efficiency.

The height of the spacer is designed so that the distance from the light emitting surface of the optical device to the cover block through the void space is small, which is effective in reducing the loss of light. It is also possible to manufacture the spacer and the mount as an integral type, and the integral type means that the component is made as a single component and the component is not bonded during the package process. Conversely, the separated type is made into different parts, And the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. .

10: Stem 11: Mounting
12a, 12b: optical element column 13a: drive driver chip
13b: ATI chip 15: spacer
17: electrical pad 20: cover block
21, 23: light guide layer 21a, 23a: mirror
25: high reflection film 27: antireflection film
30: auxiliary cover

Claims

An optical device circuit device mounted on the upper surface of the mount and having at least one of a plurality of optical element arrays, a driving driver for driving the optical element, and a processing device for processing a signal by the light received by the optical device; A stem provided at an outer periphery of the optical device at a mount, the spacer being provided above the optical device so as to secure a space for an optical interface above the optical device, and having an electrical interface with an external circuit;
And a cover block which receives the light from the light source and outputs the light to the side surface or receives light from the side surface and outputs the light to the bottom surface,
The cover block is provided with a plurality of optical guide layers having a different number of optical guide layers corresponding to the numbers of the optical element rows, and the optical guide layer corresponding to the optical element columns has an end portion on the upper side of the optical element And the light is transmitted to the optical waveguide layer along the optical waveguide layer, or the optical waveguide layer reflects the light transmitted along the optical waveguide layer to the optical waveguide.

The method according to claim 1,
Wherein the optical waveguide layer includes optical fibers corresponding to the individual optical elements forming the optical element array arranged side by side on the same plane, and the mirror constituting the inclined plane is formed at each end of the individual optical fibers.

The method according to claim 1,
Wherein the light guide layer comprises one light guide plate,
Wherein the mirror constituting the inclined surface is formed through the entire one end surface of the light guide plate to form a mirror common to all the individual optical elements constituting the optical element array.

The method of claim 3,
Further comprising an optical multiplexer for multiplexing wavelengths on the side of the optical waveguide, the side of the optical waveguide being optically interfaced with the outside of the cover block,
Wherein the optical multiplexer includes at least one of an arrayed waveguide grating (AWG) and a thin film filter (TFF).

The method according to claim 1 or 4,
And an optical coupling port is formed at a lateral side end portion of the cover block which forms an optical interface with the outside so as to form an optical interface with the outside of the cover block.

The method according to claim 1,
The distance between the optical element arrays is different from the height difference between the optical guide layers, and the inclined surface constituting the mirror of the end portion of the optical guide layer and the inclined surface constituting the mirror of the end portion of the optical guide layer of the lower portion, And the inclined surface has a 45-degree inclination.

The method according to claim 1,
Further comprising an auxiliary cover,
Wherein the spacer is formed to form a closed curve on four sides around the optical element and the cover block including the optical guide layer is coupled with the spacer to seal a portion of the plane surrounded by the closed curve,
And the remaining part of the enclosed plane is sealed with the auxiliary cover.

8. The method of claim 1 or 7,
Wherein a bottom surface of the cover block is at least partially sized and shaped to conform to the spacer such that the optical element and the tilted mirror surface of the light guide are facing most closely at a predetermined position.

The method according to claim 1,
A high reflection layer (HR coating) for enhancing the reflection efficiency is provided on the inclined mirror surface of the end portion of the optical guide layer,
And an AR coating is provided on a lower surface of the cover block below the inclined mirror surface so that light can be easily circulated to the optical element.

The method according to claim 1,
The material located between the optical guide layers constituting the cover block or the optical guide layer below the optical guide layer passes through the optical guide layer and passes through the optical guide layer An optical engine comprising a low refractive index material.