KR20150099474A - Connecter insert of expanded beam connecter - Google Patents

Abstract

The present invention relates to a beam expansion-type optical connector insert member, and more specifically, to a structure for maintaining a separation distance between an optical fiber and a lens composing a connector insert member connecting the two optical connectors including at least one optical channel in which the optical fibers to transmit an optical signal and the lens are embedded. The beam expansion-type optical connector insert member according to the present invention has at least one optical channel disposed therein to transmit an optical signal, and comprises: the optical fiber to transmit the optical signal; a ferrule in which the optical fiber is embedded; the lens separated from longitudinal ends of the optical fiber; and a metal flange in which the ferrule, which aligns an optical axis of the lens with an optical axis of the optical fibers embedded in the ferrule, is embedded. The longitudinal ends of the optical fiber are drawn inwards from a longitudinal end of the ferrule by a certain distance.

Description

[0001] The present invention relates to a beam-expanding optical connector insert member,

The present invention relates to a connector insert member of a beam-expanding optical connector, and more particularly to a connector insert member for interconnecting two optical connectors including at least one optical channel in which an optical fiber for transmitting an optical signal and a lens are embedded And a structure for maintaining a distance between the optical fiber and the lens.

Generally, in order to transmit a large amount of information at a high speed over a long distance, optical communication using an optical fiber made of glass or plastic material is utilized. In recent years, optical fiber based signal transmission methods have also been introduced due to advantages such as bandwidth, light weight, and miniaturization in interfaces between various devices based on conventional metal wires and data communication inside the devices. As optical fiber-based communication applications are expanded, optical connectors for connection between optical fibers are required to have high reliability and easy operability in various environments.

At present, a general optical connector is inserted at one side of a ferrule inserted from both sides of a ferrule so that the end of the optical fiber is matched with one end face of the ferrule by polishing and the like in the center hole of the ferrule made of ceramic, glass, And a physical contact is made in an aligned state and connected. However, when such a contact type optical connector is repeatedly connected or disconnected by the physical contact of the optical fiber with the end face of the optical fiber, there is a high possibility that the contact of the core is hindered by small fine dust or dirt. The surface of the substrate is permanently damaged, and signal transmission becomes difficult. In addition, since the contact type optical connector requires very precise alignment between both ends of the optical fiber, there is a disadvantage that it is difficult to use in a case where the installation environment such as outdoor is varied.

To overcome these drawbacks, a non-contact type beam-expanding optical connector has been developed which has high reliability in various environments. A beam-expanding optical connector is a connector that includes an optical fiber for outputting or receiving a signal and a lens for forming an optical signal into an expanded parallel beam or a parallel beam to an optical fiber core, It is resistant to contamination and provides high positional tolerance between connectors to provide reliability in poor communication environments.

Korean Patent No. 1137229 entitled " Non-contact type optical fiber connector ") has a first ferrule having a through-hole penetrating the body straight through which a first optical fiber is inserted, And a second ferrule having a through hole penetrating through the body linearly and having a second optical fiber inserted into the through hole, the first ferrule being spaced apart from a front end of the second ferrule, And a second lens positioned to be spaced from the first lens while the first optical fiber or the second optical fiber has a front portion having a diffusion portion having a larger outer diameter toward the front end.

In the case of the conventional non-contact type beam-expanding optical fiber connector, since the signal is transmitted through the parallel beam of the extended size, the permissible misalignment error between the two lenses is large, so repeated connection is easy. And high reliability can be ensured.

In addition, existing optical connectors comprise at least one optical channel including a lens and an optical fiber, and a guide pin, an insert member including a guide hole, and a connector shell providing a physical fastening to the network operator, And a receptacle built in the communication equipment and capable of receiving the plug. As described above, the structure of a general optical connector (or connector insert member) includes a lens and an optical fiber. When the lens is spherical, regardless of the radius, when the refractive index is 2, the back focal length becomes zero, It is not necessary to calculate the optimum separation distance between the optical fiber and the optical fiber. However, it is generally difficult to fabricate a lens having a refractive index of 2 at the optical communication wavelength, and the same lens can not be used depending on the structure of the optical connector. Therefore, it is required to calculate the optimum separation distance between the lens constituting the optical connector (or the connector insert member) and the optical fiber, and arrange the lens and the optical fiber so as to have the calculated separation distance.

Korean Patent No. 1137229 U.S. Patent No. 6,012,852 U.S. Patent No. 7,775,725 U.S. Patent No. 7,722,261 U.S. Patent No. 7,104,701 International Patent Publication No. 2011/014264 International Patent Publication No. 2007/119036 European Patent No. 2,270,561

In order to solve the above-mentioned problems, the present invention proposes a structure in which a lens and an optical fiber can maintain an established optimum separation distance in an optical channel including a lens and an optical fiber.

For this purpose, a connector insert member including at least one optical channel for transmitting an optical signal inside the present invention includes an optical fiber for transmitting an optical signal, a ferrule incorporating the optical fiber, a lens disposed at a certain distance from the end of the optical fiber, And a metal flange incorporating the ferrule for aligning an optical axis of the lens and an optical axis of an optical fiber embedded in the ferrule, wherein the end of the optical fiber is drawn a distance from the end of the ferrule.

For this purpose, a connector insert member including at least one optical channel for transmitting an optical signal inside the present invention includes an optical fiber for transmitting an optical signal, a ferrule incorporating the optical fiber, a lens disposed at a certain distance from the end of the optical fiber, And a metal flange incorporating the ferrule for aligning the optical axis of the lens and the optical axis of the optical fiber embedded in the ferrule, wherein the end of the optical fiber and the end of the ferrule coincide with each other, In the direction in which the lens is arranged relative to the end of the lens.

For this purpose, a connector insert member including at least one optical channel for transmitting an optical signal inside the present invention includes an optical fiber for transmitting an optical signal, a ferrule incorporating the optical fiber, a lens disposed at a certain distance from the end of the optical fiber, A metal flange incorporating the ferrule for aligning an optical axis of the lens with an optical axis of an optical fiber embedded in the ferrule, and a spacer disposed between the lens and the optical fiber.

The connector insert member for interconnecting two connectors including at least one optical channel in which an optical fiber for transmitting an optical signal in accordance with the present invention is embedded and at least one optical channel having a built-in lens, Or maintaining the set distance by making the end length of the ferrule different from the end length of the optical fiber. As described above, there is an advantage that the distance between the lens and the optical fiber can be freely adjusted as required by the method proposed by the present invention.

In addition, the present invention can adjust the separation distance between the lens and the optical fiber by filling the empty space between the lens and the optical fiber with a material having a specific refractive index, and in particular, by performing reflection coding on both sides of the spacer, It is effective.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration of a beam-expanding optical fiber coupling apparatus according to an embodiment of the present invention; FIG.
2 is a diagram illustrating a configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention.
3 is a diagram illustrating a configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention.
4 is a diagram illustrating the configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention.
FIG. 5 illustrates the light transmission efficiency according to the alignment error between the connector insert and another connector insert according to an embodiment of the present invention.
Figure 6 illustrates the structure of a connector insert member in accordance with an embodiment of the present invention.
Fig. 7 shows the structure of the optical fiber and the lens constituting the optical channel.
8 is a view for explaining a process of calculating an optimum separation distance between a lens and an optical fiber according to an embodiment of the present invention.
FIG. 9 shows a structure for maintaining an optimum separation distance between a lens and an optical fiber according to an embodiment of the present invention.
10 illustrates a structure for maintaining an optimum separation distance between a lens and an optical fiber according to another embodiment of the present invention.
11 illustrates a structure for maintaining an optimum separation distance between a lens and an optical fiber according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further aspects of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration of a beam-expanding optical fiber coupling apparatus according to an embodiment of the present invention; FIG. Hereinafter, a configuration of a beam-expanding optical fiber coupling apparatus according to an embodiment of the present invention will be described in detail with reference to FIG.

Referring to FIG. 1, the beam-expanding optical fiber connector includes a first optical fiber for outputting an optical signal, a first main lens, a second main lens, a first auxiliary lens to a fourth auxiliary lens, and a second optical fiber. In the beam-expanding optical fiber connector according to one embodiment, the first main lens and the second main lens are composed of spherical lenses. Of course, other configurations than the above-described configuration may be included in the beam-expanding optical fiber coupling apparatus proposed by the present invention.

Hereinafter, a beam-expanding optical fiber coupling device including only the first main lens and the second main lens without the first auxiliary lens to the fourth auxiliary lens will be described.

The first main lens must be disposed at a position spaced a certain distance from the optical axis of the first optical fiber in order to convert the optical signal output from the first optical fiber into parallel light. The spacing distance and the width of the optical signal emitted from the first main lens are determined by the diameter and the refractive index of the first main lens. Also, in order to collect the optical signal emitted from the first main lens and transmit it to the core of the second optical fiber, the second main lens must be disposed at a position spaced apart from the second optical fiber by a certain distance. As described above, in order to convert the optical signal emitted from the first main lens into parallel light, there is a limit in the separation distance, and the optical coupling efficiency may vary depending on the separation distance. Therefore, since the distance between the optical fiber and the lens and the lens is limited by the diameter and the refractive index of the lens, it is difficult to arrange the lens at the optimum position. Also, since the refractive index of the lens differs depending on the wavelength of light, the focus position changes and the optimum distance is changed.

Hereinafter, a beam-expanding optical fiber coupling apparatus proposed by the present invention will be described with reference to FIG. A lens for converting an optical signal output from the first optical fiber 111 into a parallel light is a first compound lens 141 and a lens for condensing the optical signal received from the first compound lens is referred to as a second compound lens 142 do.

The first optical fiber 111 forms a core through which an optical signal can be transmitted. Hereinafter, an optical signal output from the first optical fiber 111 is referred to as a first optical signal a. The first main lens 121 is disposed at a position spaced from the optical axis of the first optical fiber 111 by a predetermined distance. The first main lens 121 is composed of a spherical lens having a first refractive index and a first curvature.

The present invention proposes a beam expanding type optical fiber connector in which a first auxiliary lens 131 is provided at a front end of a first main lens 121 and a second auxiliary lens 133 is provided at a rear end thereof. The first auxiliary lens 131 has a second refractive index and a second curvature, and the second auxiliary lens 133 has a third refractive index and a third curvature.

The first auxiliary lens 131 and the second auxiliary lens 133 are preferably disposed closely to the first main lens 121 but may be spaced apart from each other by a predetermined distance.

When the first auxiliary lens 131 and the second auxiliary lens 133 are disposed at both ends of the first main lens 121 as described above, The lenses are arranged at a position spaced apart from the optical fiber 111 by a predetermined distance. At this time, the separation distance and the width of the optical signal emitted from the second auxiliary lens 133 are determined by the diameter and the refractive index of the first main lens 121, the refractive index and thickness of the first auxiliary lens 131, The refractive index and thickness of the auxiliary lens 133, and the curvature of the cross section. Therefore, by adjusting the shape and the refractive index of the first auxiliary lens 131 and the second auxiliary lens 133 in a state in which the diameter and the refractive index of the first main lens 121 are fixed, the spacing distance can be varied . That is, even when the first optical fiber 111 and the second optical fiber 112 have different distances from each other, the first auxiliary lens 131 or the second auxiliary lens 131 having a different shape or refractive index, Optical fibers having different distances from each other can be optically coupled between the first optical fiber 111 and the second optical fiber 112 by using the auxiliary lens 133. [

Further, by using the auxiliary lens having a refractive index different from that of the main lens, the refractive index and the curvature of the main lens, the curvature and the refractive index of the auxiliary lens are appropriately adjusted to minimize the focus change (chromatic aberration) This is possible.

1, the curvature of the first auxiliary lens 131 and the second auxiliary lens 133 is shown to be smaller than the curvature of the first main lens 121, but the present invention is not limited thereto. That is, as described above, the curvature of the first auxiliary lens 131 and the second auxiliary lens 133 may be designed to be larger or smaller than the curvature of the first main lens 121.

Further, in designing the auxiliary lens so that the spacing distance is '0', the optical fiber and the lens can be disposed closely to each other without considering the separation distance. Of course, in this case, the optical signal b emitted from the second auxiliary lens 133 becomes parallel light. In addition, the curvature, thickness, and refractive index of the auxiliary lens are adjusted, and the walking distance of the optical signal output from the second auxiliary lens is adjusted to be long so that the distance between the lens disposed on the first optical fiber side and the lens disposed on the second optical fiber side The width of the optical signal can be adjusted.

The second optical fiber 112 forms a core through which an optical signal can be transmitted. The second main lens 122 is disposed at a position spaced apart from the optical axis of the second optical fiber 112 by a certain distance. The second main lens 122 is composed of a spherical lens having a first refractive index and a first diameter.

The present invention proposes a beam expanding type optical fiber connector in which a third auxiliary lens 132 is provided at the front end of the second main lens and a fourth auxiliary lens 134 is provided at the rear end. The third auxiliary lens 132 has a second refractive index and a second diameter, and the fourth auxiliary lens 134 has a third refractive index and a third diameter. That is, the third auxiliary lens 132 is a lens having the same shape and refractive index as the first auxiliary lens 131, and the fourth auxiliary lens 134 is a lens having the same shape and refractive index as the second auxiliary lens 133, to be. Hereinafter, an optical signal input to the fourth auxiliary lens is referred to as a second optical signal b, and an optical signal output from the third auxiliary lens 132 is referred to as a third optical signal c.

The third auxiliary lens 132 and the fourth auxiliary lens 134 are preferably disposed closely to the second main lens 122, but they may be spaced apart from each other by a certain distance.

In addition, the optical signal transmission efficiency can be improved by optimizing the thickness, curvature, and refractive index of the auxiliary lens although the transmission efficiency of the optical signal is lowered due to the alignment error of the components and the aberration of the lens.

1 shows a case where one auxiliary lens is formed on the front end of the main lens, but the present invention is not limited thereto. That is, at least two auxiliary lenses can be formed on the front end of the main lens, and the rear end of the main lens can also form at least two auxiliary lenses. Of course, in this case, it is preferable that any one of the refractive index, the thickness, and the curvature of the auxiliary lens formed is different.

2 is a diagram illustrating a configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention. Hereinafter, a configuration of a beam expanding type optical fiber connection device according to another embodiment of the present invention will be described in detail with reference to FIG.

Referring to FIG. 2, the beam-expanding optical fiber connector includes a first optical fiber for outputting an optical signal, a first main lens, a second main lens, a first auxiliary lens, a second auxiliary lens, and a second optical fiber. Of course, other configurations than the above-described configuration may be included in the beam-expanding optical fiber coupling apparatus proposed by the present invention.

2, the first auxiliary lens 131 is disposed at the front end of the first main lens 121, and the second auxiliary lens 132 is disposed at the front end of the second main lens. It can be seen that the first auxiliary lens 131 and the second auxiliary lens 132 have a planar shape (curvature is infinite) on one side. Of course, the distance between the optical fiber and the main lens can be adjusted by adjusting the thickness or refractive index of the auxiliary lens.

3 is a diagram illustrating a configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention. Hereinafter, a configuration of a beam-expandable optical fiber coupling apparatus according to another embodiment of the present invention will be described in detail with reference to FIG.

Referring to FIG. 3, the beam-expanding optical fiber connector includes a first optical fiber for outputting an optical signal, a first main lens, a second main lens, a first auxiliary lens, a second auxiliary lens, and a second optical fiber. Of course, other configurations than the above-described configuration may be included in the beam-expanding optical fiber coupling apparatus proposed by the present invention.

3, the first auxiliary lens 131 is disposed at the front end of the first main lens 121, and the second auxiliary lens 132 is disposed at the front end of the second main lens 122, as in FIG. However, the first auxiliary lens 131 and the second auxiliary lens 132 are designed not to have a planar shape but to have a constant curvature. Of course, the distance between the optical fiber and the main lens can be adjusted by adjusting the thickness or refractive index of the auxiliary lens.

4 is a diagram illustrating the configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention. Hereinafter, a configuration of a beam-expanding optical fiber coupling apparatus according to another embodiment of the present invention will be described in detail with reference to FIG.

Referring to FIG. 4, the beam-expanding optical fiber connector includes a first optical fiber for outputting an optical signal, a first main lens, a second main lens, a first auxiliary lens, a second auxiliary lens, and a second optical fiber. Of course, other configurations than the above-described configuration may be included in the beam-expanding optical fiber coupling apparatus proposed by the present invention.

4, the first auxiliary lens 131 is disposed at the front end of the first main lens 121, and the second auxiliary lens 132 is disposed at the front end of the second main lens 122, as in FIG. The first auxiliary lens 131 and the second auxiliary lens 132 are not arranged to be in close contact with the first main lens 121 or the second main lens 122, And is disposed in close contact with the optical fiber 112. Since the first auxiliary lens 131 is in close contact with the first optical fiber 111 and the second auxiliary lens 132 is disposed in close contact with the second optical fiber 112, One side of the lens 132 is designed in a planar shape.

Of course, the auxiliary lens can be formed of an adhesive having a transparent material. In this case, the auxiliary lens can simultaneously hold the main lens and the optical fiber firmly.

Hereinafter, a connector insert member including at least one optical channel including a lens and an optical fiber will be described. Generally, a connector shell for providing physical fastening between connectors is divided into a plug and a receptacle type, and the connector insert member is built in such that mutual fastening is possible. At this time, the end surfaces of the connector insert members are in contact with each other, so that the optical axes formed in the insert are aligned parallel to each other, and the channels are aligned by engaging the guide pins formed in the end surfaces of both connector insert members and the guide holes. Hereinafter, a problem occurring due to misalignment between connector insert members will be described.

Transmission loss is very sensitive to light transmission efficiency when the alignment between the connector insert members is distorted, particularly when the fastening angle is incorrect (the optical channel in the connector insert member can not be formed horizontally). That is, as shown in FIG. 5, when a difference of angle of 0.09 degrees occurs, a loss of about 20% is caused. When a difference of 0.15 degrees occurs, a loss of about 50% occurs. In general, the end surface of the connector insert member is formed to be perpendicular to the optical axis of the internal optical channel, so that the parallelism between the optical axes can be maintained when the end surfaces of the connector insert members are in contact with each other. However, I can not.

Also, when the optical center axes of the optical channels in the connector insert member are not aligned with each other and are vertically rotated, a loss of about 20% occurs when an alignment error of 120 μm occurs as shown in FIG.

Figure 6 illustrates the structure of a connector insert member in accordance with an embodiment of the present invention. Hereinafter, the structure of the connector insert member according to one embodiment of the present invention will be described in detail with reference to FIG.

According to Fig. 6, the connector insert member includes a guide groove, a guide hole, a guide pin, and an optical channel. Of course, other configurations than those described above may be included in the connector insert member proposed in the present invention. Hereinafter, the function of each component constituting the connector insert member will be described.

The body 660 of the connector insert member and the guide pin 640 may be formed of a material such as metal or plastic.

The guide groove 610 determines a coupling position when engaged with the outer cell. That is, the guide protrusion formed on the outer cell is inserted into the guide groove 610 of the connector insert member, thereby coupling the guide groove 610 and the guide protrusion.

The guide hole 650 is engaged with a guide pin formed on another connector insert member, and the guide pin 640 is engaged with a guide hole formed on another connector insert member. The optical axes of the optical channels formed on the connector insert member to be engaged (coupled) with the optical channel 630 formed on the connector insert member by the engagement of the guide hole 650 and the guide pin 640 are aligned.

Fig. 7 shows the structure of the optical channel constituting the connector insert member. Hereinafter, the structure of the optical channel will be described with reference to FIG.

7, the optical channel includes an optical fiber 730, a ferrule 720 incorporating the optical fiber 730, a lens (not shown) for shaping the light output from the optical fiber into a parallel beam or condensing the parallel beam into a core of the optical fiber And a metal flange 750 for aligning the optical axis of the lens with the ferrule having the optical fiber of different outer diameter.

As described above, the structure of the connector insert member includes the lens 710 and the optical fiber. When the lens has a spherical shape, the back focal length becomes 0 when the refractive index is 2 irrespective of the radius, It is not necessary to calculate the optimum separation distance. However, it is generally difficult to make the refractive index of the lens at 2 at the optical communication wavelength, and it is therefore required to calculate the optimum separation distance between the lens and the optical fiber, and arrange the lens and the optical fiber so as to have the calculated separation distance.

8 shows an example of calculating the optimum separation distance between the spherical lens and the optical fiber. 8, the optimum separation distance between the lens and the optical fiber according to an embodiment of the present invention can be simply calculated by the following equation.

 [Mathematical Expression]

8, the refractive index and the diameter of the spherical lens are 'n' and 'D', respectively. The focal distance from the center of the lens, the effective focal length is 'EFL' The distance and the back focal length are 'BFL'. At this time, when the refractive index of the spherical lens is 2, BFL = 0, so that the lens can be aligned without a separation distance, but it is difficult to manufacture a lens in which the refractive index is exactly 2 at the optical communication wavelength. Therefore, it is generally necessary to realize an optimum distance according to the refractive index of the lens. Of course, the spacing can be calculated using simple formulas as above, but it is desirable to use professional optical tools such as Code V to calculate the optimum distance.

As such, the lens and the optical fiber must be aligned to have an optimal separation distance. Hereinafter, a structure of an optical channel for alignment between a lens and an optical fiber will be described.

As described above, the connector insert member includes a guide pin and a guide hole. A channel through hole having the same outer diameter as the lens is formed so that the adapter member has a positional tolerance within 10 [micro] m with respect to the guide pin and the guide hole. Shall have a vertical tolerance of less than 0.02 degrees with respect to the full cross-section of the connector insert member.

The connector insert member forms a light through hole 740 for forming the ferrule 720 constituting the optical channel and the cylindrical metal flange having the same outer diameter as the lens is responsible for the lateral alignment of the optical axis of the optical fiber with the core of the optical fiber , Precision within 1 um is required.

FIG. 9 shows a structure for providing an optimal distance between a lens and an optical fiber according to an embodiment of the present invention. Hereinafter, a structure for achieving an optimum separation distance between the lens and the optical fiber according to the embodiment of the present invention will be described in detail with reference to FIG.

In particular, FIG. 9 (a) is a view showing a state in which the front end face of the ferrule 720 incorporating the optical fiber is assembled so as to be retracted from the front end face of the metal flange 750 by a predetermined distance and the lens 710 is fixed by the front end face of the metal flange, And a distance.

9 (b) shows an assembly jig for a ferrule assembly. The ferrule 720 and the metal flange 750, which house the optical fiber 730, are assembled in a state of not damaging the end face of the optical fiber by the jig , And the jig has a shape corresponding to the distance between the calculated lens 710 and the optical fiber 730. 9A, the optical channels 720 and 730 are spaced from the lens 710 by a length corresponding to the optimum distance F between the lens 710 and the optical fibers 720 and 730, When the horizontal distance at which the end of the lens is drawn into the metal flange 750 when the lens 710 is fixed to the front end of the metal flange 750 from the front end face of the metal flange 750 is defined as L, As shown in FIG. That is, the jig shows that the depth step between the two-region groove 760 into which the metal flange 750 is inserted and the groove 770 in one region into which the ferrule 720 is drawn is 'L + F' Able to know.

And has small grooves 780 and 790 at positions where the optical fiber end faces of the upper and lower plates of the assembly jig can be brought into contact with each other so that the surface of the optical fiber on the front end or the rear end face of the ferrule is not damaged.

Further, in order to reduce the reflection loss, an anti-reflective coating may be formed on the surface of the optical fiber and the lens, or may be filled with a transparent material having a refractive index similar to that of the core in an empty space between the lens and the optical fiber. .

In addition, according to FIG. 9, by adjusting the length of the ferrule to be inserted into the metal flange by using the grooved jig, the optical path structure and the lens are not deformed according to the separation distance depending on the single mode, And the optimum distance between the optical fibers can be realized.

FIG. 10 is another view showing a structure for providing an optimum separation distance between a lens and an optical fiber according to an embodiment of the present invention. Hereinafter, a structure for providing an optimum distance between the lens and the optical fiber according to an embodiment of the present invention will be described in detail with reference to FIG.

In particular, FIG. 10 shows a structure in which a lens 810 and a spacer 810 having a specific thickness and refractive index at the end of a lens or a ferrule are used to provide an optimum separation distance between the lens 710 and the optical fibers 720 and 730 Respectively.

10, a spacer 810 is disposed between the lens 710 and the optical fibers 720 and 730, and the cross section of the spacer 810 may be formed as a plane or a spherical shape having a curvature. Of course, as described above, a transparent material such as an adhesive having a specific refractive index other than the spacer 810 may be filled between the lens 710 and the optical fibers 720 and 730.

In addition, when the optimum spacing distance varies depending on the wavelength of the transmitted signal, the spacer 810 may be designed to have an optimum spacing distance by adjusting the material and the thickness of the spacer 810 while leaving other components unchanged. In addition, in order to reduce the reflection loss caused by the spacer 810, AR coding can be applied to both ends of the spacer 810. Of course, when the refractive index of the spacer 810 is equal to or similar to the refractive index of the core or the lens, The spacer 810 does not need to be subjected to another anti-reflection coding.

FIG. 11 is another diagram showing a structure for providing an optimum distance between a lens and an optical fiber according to an embodiment of the present invention. FIG. Hereinafter, a structure for achieving an optimum separation distance between the lens and the optical fiber according to an embodiment of the present invention will be described in detail with reference to FIG.

Referring to FIG. 11, the length of the ferrule 720 is relatively longer than the length of the introduced optical fiber 730. That is, as shown in FIG. 11, the end of the ferrule 720 is formed to be longer than the end of the optical fiber 730 by an optimum separation distance. An anti-reflection coating may be formed on the surface of the lens 710 and the end of the optical fiber 730 in order to reduce reflection loss.

Of course, the inside A of the extended ferrule 720 may be filled with a material having a specific refractive index, the empty space B between the ferrule 720 and the lens 710 may be filled with a material having a specific refractive index, And the refractive indices of the materials filled in A are similar, it is possible to omit the antireflection coating on the cross section of the core. In this case, since the optimum separation distance may be long due to the refractive index of the material filled in the empty space between the lens 710 and the ferrule 720, the size of the mode of the light emitted from the optical fiber is larger than the inner diameter of the ferrule It is desirable that the optimum spacing distance is designed to be shorter than the propagation distance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention .

111: first optical fiber 112: second optical fiber
121: first main lens 122: second main lens
131 to 134: auxiliary lens
141: first complex lens 142: second complex lens
200: guide hole 202: guide groove
204: guide pin 206: optical channel
208: chin 710: lens
720: ferrule 730: optical fiber
740: channel through-hole 750: metal flange

Claims (8)

A connector insert member comprising at least one optical channel for transmitting an optical signal therein,
An optical fiber for transmitting an optical signal;
A ferrule incorporating the optical fiber;
A lens disposed at a predetermined distance from an end of the optical fiber;
And a metal flange incorporating the ferrule for aligning an optical axis of the lens with an optical axis of an optical fiber embedded in the ferrule,
And the end of the optical fiber is drawn a distance from the end of the ferrule.
The optical fiber according to claim 1, further comprising: a first space formed by an end of the optical fiber and an antireflection coating on the lens, a first space created when the end of the optical fiber is drawn a predetermined distance from the end of the ferrule, Wherein at least one of the spaces is filled with a material having a specific refractive index.
3. The connector insert member according to claim 2, wherein the refractive index of the material filled in the first space or the second space is equal to or less than a refractive index of the lens.
A connector insert member comprising at least one optical channel for transmitting an optical signal therein,
An optical fiber for transmitting an optical signal;
A ferrule incorporating the optical fiber;
A lens disposed at a predetermined distance from an end of the optical fiber;
And a metal flange incorporating the ferrule for aligning an optical axis of the lens with an optical axis of an optical fiber embedded in the ferrule,
Wherein an end of the optical fiber coincides with an end of the ferrule and an end of the metal flange is drawn out in a direction in which the lens is disposed relative to an end of the optical fiber.
The optical fiber according to claim 4, wherein a refractive index similar to the refractive index of the optical fiber core is formed in a space between the lens and the optical fiber, which is generated by the anti-reflection coating on the end of the optical fiber and the lens, or the end of the metal flange is drawn out from the end of the optical fiber, The anti-reflective coating may be omitted at the end of the optical fiber.
A connector insert member comprising at least one optical channel for transmitting an optical signal therein,
An optical fiber for transmitting an optical signal;
A ferrule incorporating the optical fiber;
A lens disposed at a predetermined distance from an end of the optical fiber;
A metal flange incorporating the ferrule for aligning an optical axis of the lens with an optical axis of an optical fiber embedded in the ferrule;
And a spacer disposed between the lens and the optical fiber.
7. The optical recording medium according to claim 6, wherein when the AR coating (anti-reflective coating) is formed on both end faces of the spacer, or if the difference between the refractive index of the spacer and the refractive index of the optical fiber is within a set error, And the connector insert member.
7. The method according to any one of claims 1 to 6,
Wherein the lens can be a spherical lens, an aspherical lens, or a composite lens.

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