KR101660958B1 - Bi-directional optical module - Google Patents

Abstract

The present invention relates to: a case; A receptacle including an optical fiber for outputting a first optical signal, the receptacle being coupled to the case; An optical receiver for receiving the first optical signal; An optical transmitter for outputting a second optical signal to the optical fiber; And an optical filter disposed between the optical fiber and the optical transmitter for reflecting the first optical signal to the optical receiver side and the second optical signal to be transmitted, the receptacle including: a holder coupled to the case; A stub coupled to the holder and having the optical fiber disposed therein; And a fixing ring that is fitted in the stub and fixed to the holder.

Description

Bi-directional optical module < RTI ID = 0.0 >

The present invention relates to an optical transceiver module used in an optical communication system.

Generally, an optical transmission / reception module refers to a module in which various optical communication functions are accommodated in one package and connected to an optical fiber. 2. Description of the Related Art In recent years, a bidirectional optical module in which an optical transmitter using a laser diode as a light source and an optical receiver using a photodiode as an optical receiver are modularized is widely used.

The bidirectional optical transmission / reception module basically includes an optical transmitter, an optical receiver, an optical filter, an optical fiber, and a receptacle in which an optical fiber is accommodated. In addition, an isolator is mounted between the optical fiber and the laser diode to prevent the characteristics of the laser diode from becoming unstable due to reflection noise.

In general, the optical transceiver module is connected to a receptacle of a connector of an external host. At this time, the optical fiber disposed in the receptacle and the optical fiber disposed in the host connector are physically contacted and optically coupled. If the receptacle and the optical fiber of the connector are not correctly coupled, the performance of the optical transmitter or the optical receiver deteriorates due to optical feedback generated at the interface.

The present invention provides a bidirectional optical transceiver module that is easily optically coupled to an optical connector of an external host.

A bidirectional optical T / R module according to one aspect of the present invention includes: a case; A receptacle including an optical fiber for outputting a first optical signal, the receptacle being coupled to the case; An optical receiver for receiving the first optical signal; An optical transmitter for outputting a second optical signal to the optical fiber; And an optical filter disposed between the optical fiber and the optical transmitter for reflecting the first optical signal to the optical receiver side and the second optical signal to be transmitted, the receptacle including: a holder coupled to the case; A stub coupled to the holder and having the optical fiber disposed therein; And a retaining ring fitted in the stub and fixed to the holder.

In the bidirectional optical T / R module according to one aspect of the present invention, the fixing ring includes at least one flat surface and a curvature surface formed on the outer circumferential surface.

In the bidirectional optical transceiver module according to one aspect of the present invention, the stub includes a first surface, a second surface opposed to the first surface, and a through hole through which the optical fiber is disposed in a longitudinal direction. The first surface includes a flat portion and a flat portion An inclined portion having a predetermined angle as a reference, and a boundary portion formed between the flat portion and the inclined portion.

In the bidirectional optical transceiver module according to an aspect of the present invention, at least one of the plurality of flat surfaces and the imaginary line extending the boundary portion are substantially parallel.

In the bidirectional optical transceiver module according to one aspect of the present invention, the other surface of the stub may be inclined at a predetermined angle with respect to the flat portion.

In the bidirectional optical transceiver module according to one aspect of the present invention, the imaginary line extending the boundary does not intersect the virtual line extending the through hole.

In the bidirectional optical transceiver module according to one aspect of the present invention, the flat surface substantially parallel to the imaginary line extending the boundary portion may be disposed substantially horizontally or vertically with respect to the side surface of the case.

In the bidirectional optical transceiver module according to one aspect of the present invention, a sleeve inserted into the holder and covering the stub; And a connector housing inserted into the holder to cover the sleeve and having a housing space therein.

In the bidirectional optical transceiver module according to one aspect of the present invention, a slit may be formed in the longitudinal direction of the stub.

According to the present invention, the optical coupling surface of the stub that contacts the ferrule of the external connector can be disposed at an accurate angle and direction.

Therefore, the optical coupling between the external connector and the optical transceiver module to be combined is excellent.

1 is a conceptual diagram of a bidirectional optical T / R module according to an embodiment of the present invention,
2 is an exploded perspective view of a receptacle according to an embodiment of the present invention,
3 is a conceptual view showing a state where an external connector is coupled to a receptacle according to an embodiment of the present invention,
4 is a conceptual view showing the optical coupling between the external connector and the receptacle according to the present invention,
5 is a perspective view for explaining a state in which a stub of a receptacle and a retaining ring are engaged with each other according to the present invention,
6 is a perspective view showing a state in which an inclined portion is formed on one surface of a stub according to the present invention,
FIG. 7 is a cross-sectional view showing a state where a stub according to the present invention is coupled to a holder,
Fig. 8 is a view seen from Fig. 7 in direction A,
9 is a cross-sectional view showing a state where the sleeve and the connector housing according to the present invention are coupled to the holder,
10 is a perspective view of a bidirectional optical T / R module according to the present invention,
11 is a conceptual diagram showing a state in which a parallel optical lens is mounted on a receptacle according to an embodiment of the present invention,
12 is a conceptual diagram for explaining a state in which a light signal incident on a second optical filter by a parallel optical lens according to an embodiment of the present invention is converted into parallel light.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the present invention, the terms "comprising" or "having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It is to be understood that the drawings are to be construed as illustrative and not restrictive.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

1 is a conceptual diagram of a bidirectional optical T / R module according to an embodiment of the present invention.

Referring to FIG. 1, an optical module according to an embodiment of the present invention includes a case 100, a receptacle 200 including an optical fiber 211 for outputting one optical signal, An optical transmitter 400 for outputting a second optical signal to the optical fiber 211 and a first optical filter 510 disposed between the optical fiber 211 and the optical transmitter 300 .

The case 100 is formed with a plurality of openings into which the optical fiber 211, the optical transmitter 300, and the optical receiver 400 are inserted. The optical fiber 211 and the optical transmitter 300 are disposed to face each other in the case 100 and the optical receiver 400 may be disposed in a direction perpendicular to the direction in which the optical fiber 211 is inserted. However, the present invention is not limited thereto, and the optical transmitter 300 may be disposed in a direction perpendicular to the direction in which the optical fiber 211 is inserted.

The receptacle 200 is connected to an external connector and outputs a first optical signal output from the outside to the first optical filter 510. The receptacle 200 includes a holder 230 coupled to the case 100, a stub 210 fitted to the holder 230 and having an optical fiber 211 disposed therein, a sleeve 240 coupled to the stub 210, And a connector housing 250 coupled to the holder 230.

The ends of the optical fibers 211 may be disposed inside the case 100. The optical fiber 211 transmits the second optical signal output from the optical transmitter 300 to an external connector or outputs a first optical signal received from the outside.

The optical transmitter 300 transmits the first optical signal to the outside through the optical fiber 211. The first optical signal has a wavelength different from that of the second optical signal output from the optical fiber 211. The optical transmitter 300 may be applied to all structures of a general TiO can including a light source 310, a header 320, and a lens 330.

The light source 310 is formed of a semiconductor light emitting element, converts an electrical signal into an optical signal, and outputs the optical signal. As the light source 310, a laser diode may be used. The laser diode is suitable as a light source for optical communication because it has a low power consumption and narrow spectrum and can collect light of high output finely.

The header 320 on which the light source 310 is mounted is formed in a disk shape, and a plurality of connection pins 340 are inserted through the header 320. The connection pin 340 forms an electrical path between the light source 310 and an external circuit board (not shown). For example, a positive (+) signal, a negative (-) signal, and a ground signal may be output to each connection pin 340.

The lens 330 transmits the optical signal output from the light source 310 to the optical fiber 211 side. The lens 330 may be disposed at an appropriate position to transmit the optical signal to the optical fiber 211 side.

The distance adjusting member 600 includes a first adjusting member 610 disposed on the other side of the case 100 and a second adjusting member 620 inserted and fixed to the first adjusting member 610. The distance by which the second optical signal emitted from the optical transmitter 300 reaches the optical fiber 211 is adjusted according to the degree of insertion of the second adjusting member 620 and the first adjusting member 610. Accordingly, the output of the optical transmitter 300 can be adjusted according to the degree of insertion of the second adjusting member 620 and the first adjusting member 610. The optical transmitter 300 is inserted and fixed to one side of the second adjusting member 620.

The first adjusting member 610 and the second adjusting member 620 are formed in an empty cylindrical shape and have different diameters. The second adjusting member 620 is inserted into the first adjusting member 610 at a proper position, and then fixed by welding or the like. Here, the proper position refers to a position adjusted to the required second optical signal output level.

The optical receiver 400 converts the optical signal received from the outside through the optical fiber 211 into an electrical signal. The optical receiver 400 may be a photodiode. When the optical signal is incident on the photodiode, a reverse current proportional to the incident light amount flows. That is, the optical receiver 400 can convert the optical signal into an electrical signal by changing the output current according to the amount of incident light. .

The first optical filter 510 is an optical filter and may be disposed between the optical transmitter 300 and the optical fiber 211 to pass the optical signal transmitted from the optical transmitter 300, . At this time, the first filter 510 may be designed to pass only an optical signal of a specific wavelength. For example, the first filter may pass the second optical signal transmitted from the optical transmitter 300, and may reflect the first optical signal received from the outside via the optical fiber 211. At this time, the first optical filter 510 may be a 45-degree filter, and may reflect an optical signal received from the outside through the optical fiber 211 in a direction perpendicular to the incident direction. When the wavelength interval between the first optical signal and the second optical signal is narrow, the first optical filter 510 may divide the optical output instead of splitting the wavelength. (Tap Filter)

The second optical filter 530 is an optical filter that passes the optical signal reflected by the first filter 510. The first optical signal having passed through the second filter 530 is transmitted to the optical receiver 400 and converted into an electrical signal by the optical receiver 400. In one example, the second filter may be disposed on top of the first filter to pass the vertically reflected optical signal by the first filter 510, and may be configured as a zero degree filter.

The isolator 520 blocks the optical signal reflected and received by the optical fiber 211 or an optical component included in the optical module. The isolator 520 may include a polarizer for passing only an optical signal having a predetermined polarization component, an analyzer, and a Faraday rotator for rotating the optical signal input thereto by 45 degrees in linear polarization.

FIG. 3 is a conceptual view showing a state where an external connector is coupled to a receptacle according to an embodiment of the present invention. FIG. Fig. 7 is a conceptual view showing optical coupling of the receptacle according to the first embodiment.

2 and 3, the receptacle 200 includes a holder 230 coupled to a case, a stub 210 fitted in the holder 230 and having an optical fiber 211 disposed therein, a stub 210, A connector 240 coupled to the holder 230, and a connector housing 250 coupled to the holder 230.

The holder 230 may have an isolator accommodating portion 262 and a first optical filter disposing surface 261 at the end and step portions 231, 232 and 233 may be formed in the longitudinal direction.

The stub 210 is constrained to the holder 230 by the fixing ring 220, and the optical fiber 211 is disposed therein. A space 260 is formed in the sleeve 240 and the connector housing 250 to accommodate the external connector 1. Specifically, the sleeve 240 may have a slit 241 formed in the longitudinal direction thereof to press-fit the ferrule 10 of the external connector to be inserted. With this structure, the external connector 1 can be freely mounted or detached.

The stub 210 includes a through hole through which the optical fiber 211 is disposed, and includes a first surface 212 and a second surface 213 on which the optical fiber is exposed. One surface 212 is disposed opposite the first optical filter and the other surface 213 is disposed facing the external connector 1. [

The other surface 213 is formed to be inclined at a predetermined angle and physically contacted with the ferrule 10 of the external connector 1. Referring to FIG. 4, the ferrule 10 of the external connector 1 and the stub 210 of the receptacle 200 are formed with inclined surfaces corresponding to each other and physically contacted with each other. Specifically, the inclination angle of the ferrule 10 and the other surface 213 can be appropriately adjusted according to a predetermined standard. As an example, the inclination angle of the other surface 213 may be about 8 degrees.

This optical connection can be defined as an APC type (Angled Physical Contact). In the APC type, a second optical signal OL2 output from an optical transmitter to an external host and a first optical signal OL1 output from an external host to an optical receiver are input to the external optical fiber 11 and the stub 210, It is possible to suppress the problem of reflection at the interface between the first electrode 210 and the second electrode 210. [

FIG. 5 is a perspective view for explaining a state where a stub of a receptacle and a retaining ring are engaged with each other according to the present invention, FIG. 6 is a perspective view showing a state where a slope is formed on one surface of a stub according to the present invention, Fig. 3 is a cross-sectional view showing a state in which the stub is attached to the holder.

Referring to FIG. 5, the assembling process of the receptacle 200 first inserts the fixing ring 220 into the stub 210. The fixing ring 220 has a through hole 221 formed therein and a plurality of flat surfaces 222 and curvature surfaces 223 on the outer circumferential surface thereof. Any one of the flat surfaces 222 may be a reference flat surface 222 formed with an alignment mark 222a. A flat surface 222 perpendicular to the reference flat surface 222 having the alignment marks 222a may be formed in the flat surface 222. [ For example, the flat surface 222 and the curvature surface 223 may be alternately formed, and the line extending the flat surface 222 may have a virtual polygonal shape.

Thereafter, one surface 212 of the stub 210 is processed as shown in FIG. Specifically, the flat surface 222 of the stationary ring 220 is mounted on a jig to process the one surface 212 of the stub 210.

On one surface 212 of the stub 210 is formed a flat portion 212a, an inclined portion 212b having a predetermined angle with respect to the flat portion 212a, and an inclined portion 212b formed between the flat portion 212a and the inclined portion 212b A boundary portion 212c is formed.

The inclined portion 212b is processed at a predetermined angle so that the path of the light emitted from the optical fiber coincides with the optical transmitter. Therefore, since the cross section of the optical fiber is also processed at the same angle, the extension line of the boundary portion 212c does not cross the optical fiber. For example, the inclined portion 212b can be machined at about 5 to 10 degrees with reference to the flat surface of the flat portion 212a (VA in Fig. 3).

At this time, the virtual line L1 extending the inclined portion 212b is processed so as to be parallel to the reference flat surface 222 on which the alignment mark 222a is formed. Thus, the alignment mark 222a can be accurately positioned on the top of the stub 210. [

Then, the other surface 213 of the stub 210 is machined. The other surface 213 of the stub 210 is machined to have an appropriate slope capable of being physically bonded to the above-described ferrule of the external connector. The reference surface 222 is positioned on the upper side of the stub 210 because the reference surface 222 is processed on the basis of a state in which the reference flat surface 222 is positioned on the upper side of the stub 210. [ State optical transceiver module, it can be placed in contact with the ferrule precisely.

FIG. 7 is a cross-sectional view showing a state where the stub according to the present invention is coupled to a holder, FIG. 8 is a view seen from a direction A in FIG. 7, and FIG. 9 is a view showing a state in which a sleeve and a connector housing according to the present invention are coupled to a holder 10 is a perspective view of a bidirectional optical T / R module according to the present invention.

7, the holder 230 includes a first insertion hole h1 through which the fixing ring 220 is inserted, a third insertion hole h3 through which the connector housing 250 is coupled, and a first insertion hole h1 And a second insertion hole h2 connecting the third insertion hole h3. The stub 210 to which the stationary ring 220 is coupled is inserted into the first insertion hole h1 of the holder 230. [

Referring to FIG. 8, the curved surface 223 of the stationary ring 220 is fitted to the inner surface of the first insertion hole h1, thereby fixing the stub 210 to the holder 230. The imaginary line L4 extending from the cut-out portion 233a formed on the outer circumferential surface of the holder 230 and the extension line L3 of the flat surface 222 are arranged to be parallel or perpendicular.

That is, the reference flat surface 222 on which the alignment mark is formed is arranged so as to be perpendicular to the virtual line L4, and the extension line L3 of the flat surface 222 perpendicular to the reference flat surface 222 is located on the imaginary line L4 As shown in Fig. Then, as shown in FIG. 9, the sleeve 240 and the connector housing 250 are coupled to the holder 230 in order to complete the assembling of the receptacle 200.

10, the imaginary line L4 extending from the cut-out portion 233a of the holder 230 is kept horizontal with the imaginary line L5 extending the side surface of the case 100 The receptacle 200 is inserted into the case.

That is, the reference flat surface 222 on which the alignment mark is formed is perpendicular to the imaginary line L5 extending the side surface of the case 100, so that the reference flat surface 222 is coupled to the optical transceiver module in a state of being disposed on the upper part of the stub 210 . Thus, the other surface 213 of the stub 210 can be placed in contact with the ferrule precisely.

However, the present invention is not limited thereto. The cut-out portion 233a of the holder 230 may be horizontally arranged with the reference flat surface 222 on which the alignment marks are formed, and then the cut- 233a may be arranged parallel to the upper surface of the case 100. [

That is, the cut-out portion 233a of the holder 230 is coupled to the case 210 in a state in which the stationary ring 220 coupled to the stub 210 is initially placed (as a standard when the stub is machined) If it can be done, it can be variously modified.

FIG. 11 is a conceptual diagram showing a state in which a parallel optical lens is mounted on a receptacle according to an embodiment of the present invention. FIG. 12 is a view showing a state in which the optical signal input to the second optical filter by the parallel optical lens according to an embodiment of the present invention And is converted into parallel light.

Referring to FIG. 11, the receptacle 200 is provided with a fixing member 280 on which the parallel optical lens 540 is mounted. The fixing member 280 may be integrally formed with the receptacle 280 or may be separately manufactured and mounted on the receptacle 200. [ The fixing member 280 is formed in a ring shape, and the parallel optical lens 540 can be inserted and fixed therein.

A seating groove 281 in which the second optical filter 530 is disposed may be further formed on the fixing member 280. According to this structure, the parallel optical lens 540 and the second optical filter 530 can be fixed to the fixing member 280 at the same time, so that the installation is simple and the degree of integration can be improved. The collimated optical lens 540 may be a collimating lens.

12, the first optical signal reflected by the first optical filter 510 includes a plurality of divergent lights L12 and L13 in addition to the parallel light L11 perpendicularly incident on the second optical filter 530 . Since the divergent lights L12 and L13 are incident on the second optical filter 530 at a predetermined angle, there is a problem that the isolation characteristic of the second optical filter 530 is lowered.

However, according to the present invention, the divergent lights L12 and L13 are converted into substantially parallel light by the parallel optical lens 540. [ Therefore, since the first optical signals L11, L12, and L13 are incident substantially perpendicularly to the second optical filter 530, the isolation characteristics of the second optical filter 530 are improved and the communication quality can be improved.

100: Case
200: Receptacle
211: Optical fiber
210: stub
220: Retaining ring
230: holder

Claims (11)

case;
A receptacle including an optical fiber for outputting a first optical signal, the receptacle being coupled to the case;
An optical receiver for receiving the first optical signal;
An optical transmitter for outputting a second optical signal to the optical fiber; And
A first optical filter disposed between the optical fiber and the optical transmitter for reflecting the first optical signal to the optical receiver side and transmitting the second optical signal,
Wherein the receptacle includes:
A holder coupled to the case;
A stub coupled to the holder and having the optical fiber disposed therein; And
And a fixing ring fitted to the stub and fixed to the holder,
Wherein the stationary ring includes at least one flat surface formed on an outer circumferential surface and a curvature surface,
Wherein the stub includes a first surface, a second surface facing the first surface, and a through hole through which the optical fiber is disposed in the longitudinal direction,
Wherein the one surface includes an inclined portion having a flat portion and a predetermined angle with respect to the flat portion, and a boundary portion formed between the flat portion and the inclined portion.
delete delete The method according to claim 1,
Wherein at least one of the plurality of flat surfaces is substantially parallel to a virtual line extending from the boundary portion.
The method according to claim 1,
Wherein the other surface of the stub is inclined at a predetermined angle with respect to the flat portion.
The method according to claim 1,
Wherein the imaginary line extending from the boundary does not intersect a virtual line extending through the through hole.
5. The method of claim 4,
A first insertion groove for receiving the stationary ring is formed in the holder,
Wherein the curved surface of the stationary ring contacts the inner circumferential surface of the first insertion groove.
8. The method of claim 7,
Wherein the flat surface substantially parallel to the imaginary line extending the boundary portion is substantially horizontal or perpendicular to the side surface of the case.
The method according to claim 1,
A sleeve inserted into the holder to cover the stub; And
And a connector housing inserted into the holder to cover the sleeve and having a housing space therein.
10. The method of claim 9,
Wherein the stub has a slit in the longitudinal direction.
The method according to claim 1,
A second optical filter disposed between the first optical filter and the optical receiver,
A parallel optical lens disposed between the first optical filter and the second optical filter, and
And a fixing member fixed to the receptacle to receive the parallel optical lens.

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