JP2017207788A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical receptacle that can appropriately perform optical transmission involving monitoring, simplify a configuration, and improve mechanical strength and the degree of freedom in design, and an optical module including the optical receptacle.SOLUTION: An optical receptacle includes: a first lens surface 11 arranged on a first surface 2a at a photoelectric conversion device 3 side of an optical receptacle body so that part of light of a light-emitting element 7 goes into it; a first reflection surface 14 arranged on a second surface 2b opposite to the first surface 2a and reflecting the light going into the first lens surface 11; and a second reflection surface 16 arranged next to the first lens surface 11 on the first surface 2a so that another part of the light of the light-emitting element 7 goes into it, and reflecting the incident other part of the light toward a light-receiving element 8 as monitor light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical receptacle and an optical module including the same, and more particularly, to an optical receptacle suitable for optically coupling a light emitting element and an optical transmission body, and an optical module including the optical receptacle.

  Conventionally, an optical module including a light emitting element such as a surface emitting laser (for example, VCSEL: Vertical Cavity Surface Emitting Laser) has been used for optical communication using an optical fiber.

  In this type of optical module, an optical module component called an optical receptacle is used, and this optical receptacle is formed by coupling light including communication information emitted from a light emitting element to an end face of an optical fiber. It has been used for optical transmission via an optical fiber.

  Conventionally, in an optical module, for the purpose of stabilizing the output characteristics of the light emitting element with respect to temperature changes and adjusting the light output, the light (intensity and light quantity) emitted from the light emitting element has been monitored. Various proposals have been made.

  For example, in Patent Document 1, a part of light emitted from a light emitting element is used as monitor light by using Fresnel reflection by a reflection / transmission surface formed by an inner surface of a first recess formed in a lens array. A technique for reflecting light is proposed.

JP2011-039151A

  The technique described in Patent Document 1 described above has an advantage that the number of components required for obtaining monitor light can be reduced by using Fresnel reflection, while the emitted light of the light emitting element is used as the monitor light and the optical fiber. It is indispensable to form the first recess for splitting the light into the coupled light to the light and to form the second recess for directing the traveling direction of the monitor light to the light receiving element side using reflection. There is a limit to the simplification of the structure and the improvement of the mechanical strength.

  Further, the technique described in Patent Document 1 is configured such that the monitor light after being reflected by the reflection / transmission surface is subjected to two direction changes such as refraction and reflection in the second concave portion. It is difficult to design the light receiving element for receiving light freely.

  Therefore, the present invention has been made in view of the above points, and can appropriately realize optical transmission with a monitor, simplify the configuration, and improve the mechanical strength and the degree of design freedom. It is an object of the present invention to provide an optical receptacle that can be used, and an optical module including the same.

  In order to achieve the above object, the optical receptacle according to claim 1 of the present invention is characterized in that a light emitting element and a light receiving element for receiving monitor light for monitoring light emitted from the light emitting element are mounted on a substrate. An optical receptacle in which the light emitting element and the optical transmission body can be optically coupled with each other in a state of being disposed between the photoelectric conversion device and the optical transmission body. A first lens surface disposed so that a part of the light of the light emitting element is incident on a first surface on the conversion device side, and a side opposite to the first surface of the optical receptacle body The second surface has a predetermined first tilt angle with respect to the first surface, and is arranged so that the part of the light incident on the first lens surface reaches the first surface. Reflect the part of the light A first reflecting surface, an exit surface for emitting the part of the light reflected by the first reflecting surface toward the optical transmission body, and the first lens on the first surface. And the light emitted from the light emitting element is arranged so that a part of the light other than the part of the light is incident thereon, and the other part of the incident light is used as the monitor light. A part of the chordal portion of the first lens surface, which is a second reflecting surface that is reflected toward the light receiving element and has a top portion through which the optical axis passes and a chord-like portion surrounding the top portion. Is formed in place of the chord-like portion that continues to the top portion, and is formed only by the surface shape of the portion adjacent to the first lens surface in the optical receptacle main body, and the other part that is incident As the monitor light by total reflection or Fresnel reflection only A second reflecting surface that reflects toward the light receiving element, and a center portion of the light emitting element is shifted to the second reflecting surface side with respect to the optical axis on the first lens surface. Is located at the point.

  According to the first aspect of the invention, the second reflecting surface connected to the first lens surface causes the other part of the light of the light emitting element to be directed to the light receiving element as monitor light. Since it can be reflected, it is possible to eliminate the need for a concave portion for spectroscopy, and light transmission with a monitor can be realized with a simple and robust configuration. Further, since the monitor light is configured to be incident on the light receiving element without being redirected on the optical path after the second reflecting surface, the light receiving element can be selected only by selecting the surface shape of the second reflecting surface. Therefore, it is possible to easily design the optical path of the monitor light suitable for the free arrangement position. In addition, since the second reflecting surface is formed in place of a part of the chord-like portion of the first lens surface, it is a portion that is reliably irradiated with light from the light emitting element. It is possible to reflect the monitor light and to realize a highly reliable monitor. Further, the second reflecting surface is formed only by a surface shape of a part adjacent to the first lens surface in the optical receptacle body, and the monitor light is reflected by Fresnel reflection of the other part of the light. Since it is generated, it can be realized only by the surface shape of the optical receptacle body, and the number of parts can be suppressed. Further, since the central portion of the light emitting element is disposed at a position shifted to the second reflecting surface side with respect to the optical axis on the first lens surface, monitor light can be obtained more reliably. it can.

  Further, the optical receptacle according to claim 2 is characterized in that, in claim 1, the second reflecting surface has an inclined plane that forms a predetermined second inclination angle with respect to the first surface. It is in.

  And according to the invention concerning this Claim 2, the surface shape of the 2nd reflective surface can be simplified.

  Furthermore, the optical receptacle according to claim 3 is characterized in that, in claim 1 or 2, the second reflecting surface has a concave curved surface directed toward the light receiving element.

  According to the third aspect of the present invention, the function of condensing the monitor light can be imparted to the second reflecting surface, so that the monitor light can be efficiently coupled to the light receiving element.

  According to a fourth aspect of the present invention, there is provided the optical receptacle according to any one of the first to third aspects, wherein the emission surface is a second lens surface that converges and emits the partial light. There is in point.

  According to the fourth aspect of the present invention, the light of the light receiving element can be efficiently coupled to the optical transmission body.

  Furthermore, the optical receptacle according to claim 5 is characterized in that, in any one of claims 1 to 4, the first reflecting surface has an incident angle at which the part of light is larger than a critical angle. It is in that it is a total reflection surface that totally reflects the part of the incident light that is incident and incident internally.

  According to the fifth aspect of the present invention, since the first reflecting surface can be realized only by the surface shape of the optical receptacle body, the number of parts can be reduced.

  Furthermore, the optical module according to claim 6 is characterized in that it includes the optical receptacle according to any one of claims 1 to 5 and the photoelectric conversion device according to claim 1.

  According to the sixth aspect of the present invention, optical transmission with a monitor can be realized with a simple and robust configuration, and the arrangement position of the light receiving element and the optical path of the monitor light suitable for the light receiving element can be realized. Can also be designed freely. In addition, by using a substrate mounting type photoelectric conversion device, it is possible to avoid the problem of crosstalk that may occur when using TO-CAN.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to implement | achieve optical transmission with a monitor appropriately, the simplification of a structure and the improvement of mechanical strength and the freedom degree of design can be aimed at.

1 is a schematic configuration diagram showing an embodiment of an optical receptacle according to the present invention and an optical module including the same. Plan view of the optical receptacle shown in FIG. 1 is a bottom view of the optical receptacle shown in FIG. 1 is an enlarged bottom view of the main part of the optical receptacle shown in FIG. FIG. 1 is an enlarged vertical sectional view of a main part showing a spectral state in the optical module of FIG. Schematic diagram showing an example of the spot shape of the fiber coupled light in the optical module of FIG. Schematic diagram showing an example of the spot shape of monitor light in the optical module of FIG. The principal part expanded longitudinal cross-sectional view which shows the 1st modification of this invention The principal part enlarged bottom view of the optical receptacle which shows the 2nd modification of this invention FIG. 9 is an enlarged vertical cross-sectional view of a main part showing a spectral state by the optical receptacle of FIG. Schematic block diagram of an optical module showing a third modification of the present invention The right side view of the optical receptacle shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an optical receptacle according to the present invention and an optical module including the optical receptacle will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram showing an outline of an optical module 1 in the present embodiment together with a longitudinal sectional view of the optical receptacle 2 in the present embodiment (corresponding to the AA sectional view in FIG. 2). FIG. 2 is a plan view of the optical receptacle 2 shown in FIG. FIG. 3 is a bottom view of the optical receptacle 2 shown in FIG.

  As shown in FIG. 1, the optical receptacle 2 (optical receptacle main body) in this embodiment is arrange | positioned between the photoelectric conversion apparatus 3 and the optical fiber 5 as an optical transmission body.

  Here, the photoelectric conversion device 3 in FIG. 1 is a substrate-mounted photoelectric conversion device 3. That is, as shown in FIG. 1, the photoelectric conversion device 3 includes an optical receptacle 2 in a semiconductor substrate (circuit board) 6 arranged in parallel to the lower end surface 2 a (plane) of the optical receptacle 2 as a first surface. On the side surface (upper surface), there is one light emitting element 7 that emits (emits) laser light La in a direction perpendicular to the surface (upward direction). Vertical cavity surface emitting laser). Further, the photoelectric conversion device 3 is provided on the surface of the semiconductor substrate 6 on the side of the optical receptacle 2 and on the right side in FIG. 1 with respect to the light emitting element 7 (for example, the output of the laser light La emitted from the light emitting element 7 (for example, It has one light receiving element 8 that receives monitor light M for monitoring intensity and light quantity. The light receiving element 8 may be a photo detector. Further, although not shown, on the surface of the semiconductor substrate 6 on the side of the optical receptacle 2, the output of the laser light La emitted from the light emitting element 7 based on the intensity and light quantity of the monitor light M received by the light receiving element 8. An electronic component such as a control circuit for controlling the electronic component is mounted, and the electronic component is electrically connected to the light emitting element 7 and the light receiving element 8 through wiring. Such a photoelectric conversion device 3 is attached to the optical receptacle 2 by known fixing means such as an adhesive (for example, heat / ultraviolet curable resin) disposed between the semiconductor substrate 6 and the optical receptacle 2. Thus, the optical module 1 is configured together with the optical receptacle 2.

  As shown in FIG. 1, the optical fiber 5 has a cylindrical optical fiber mounting portion formed on the optical receptacle 2 along with a cylindrical ferrule 9 having a predetermined length on the end face 5a side. The unit 4 is detachably attached. In this attached state, a part of the optical fiber 5 on the side of the end surface 5 a (part accommodated in the optical fiber attaching part 4) is parallel to the semiconductor substrate 6. The optical fiber 5 may be either a single mode optical fiber or a multimode optical fiber.

  The optical receptacle 2 optically couples the light emitting element 7 and the end face 5a of the optical fiber 5 in a state where the optical receptacle 2 is disposed between the photoelectric conversion device 3 and the optical fiber 5. .

  The optical receptacle 2 will be described in more detail. As shown in FIG. 1, the optical receptacle 2 has an outer shape of a main part having various optical surfaces formed in a substantially rectangular parallelepiped shape. That is, as shown in FIGS. 1 to 3, the main part of the optical receptacle 2 is composed of a lower end surface 2a, an upper end surface 2b as a second surface, a left end surface 2c, a right end surface 2d, a front end surface 2e, and a rear end surface 2f. Each surface forms a rough outline. The upper and lower end faces 2a, 2b are parallel to each other, and the left and right end faces 2c, 2d are also parallel to each other. Furthermore, the upper and lower end faces 2a, 2b and the left and right end faces 2c, 2d are perpendicular to each other. In addition, the optical fiber attachment part 4 mentioned above is formed so that it may extend rightward from the right end surface 2d. However, it is not necessary to be limited to such a configuration. For example, when the optical receptacle 2 is obtained by injection molding using a translucent resin material such as polyetherimide, the left and right end faces 2c, 2d, etc. A taper for releasing the molded product from the mold may be formed.

  As shown in FIG. 1, on the lower end surface 2a of the optical receptacle 2, a first recess 10 having a substantially trapezoidal cross section recessed upward with respect to the lower end surface 2a is formed. The inner bottom surface 10a of the recess 10 is formed in parallel to the lower end surface 2a. As shown in FIGS. 1 and 3, one first lens surface 11 is formed at a position near the left end in FIGS. 1 and 3 on the inner bottom surface 10 a of the first recess 10. . Here, as shown in FIGS. 3 and 4, the first lens surface 11 has a circular part (a portion in a predetermined range on the right end side) cut out in a straight line (string shape) in the bottom view. In addition, as shown in FIG. 1, it is formed on a spherical or aspherical convex lens surface with a convex surface facing the light emitting element 7 side. The axial direction of the optical axis OA (1) on the first lens surface 11 may be orthogonal to the lower end surface 2a.

  As shown in FIG. 5 (corresponding to the BB cross-sectional view of FIG. 4), the first lens surface 11 has a light-emitting element 7 in a state where the photoelectric conversion device 3 is attached to the optical receptacle 2. A part of the emitted laser beam La is incident from below. Then, the first lens surface 11 advances a part of the incident laser light La to the inside of the optical receptacle 2 as fiber coupling light Lc to be coupled to the end surface 5a of the optical fiber 5.

  As shown in FIGS. 1 and 2, the position on the traveling direction side of the fiber coupled light Lc with respect to the first lens surface 11 on the upper end surface 2b of the optical receptacle 2 (a position directly above in FIG. 1). A first reflecting surface 14 having a predetermined first tilt angle with respect to the lower end surface 2a, which tilts to the right as it goes upward, is formed. As shown in FIG. 1, the first reflecting surface 14 is composed only of the inner slope of the second recessed portion 15 having a substantially trapezoidal cross-section that is recessed downward on the upper end surface 2 b.

  As shown in FIG. 1, the fiber-coupled light Lc that has passed through the first lens surface 11 has such a critical angle from the lower side (inner side of the optical receptacle 2) in FIG. Internal incidence (arrival) at a larger incident angle than. The first reflecting surface 14 totally reflects the internally incident fiber coupled light Lc toward the right in FIG.

  The tilt angle of the first reflecting surface 14 may be 45 ° counterclockwise in FIG. 1 with the lower end surface 2a as a reference (0 °) from the viewpoint of simplification of design and dimensional accuracy measurement.

  Furthermore, as shown in FIG. 1, one second lens surface 12 as an emission surface is formed at a position facing the end surface 5 a of the optical fiber 5 on the right end surface 2 d of the main part of the optical receptacle 2. . The second lens surface 12 is formed in a spherical or aspherical convex lens surface with a convex surface facing the end surface 5 a side of the optical fiber 5 while the outer peripheral shape is formed in a circular shape. The optical axis OA (2) on the second lens surface 12 is preferably coincident with the central axis of the end surface 5a of the optical fiber 5.

  As shown in FIG. 1, the fiber coupled light Lc totally reflected by the first reflecting surface 14 is incident on the second lens surface 12 as described above. The second lens surface 12 emits the internally incident fiber coupled light Lc toward the end surface 5a of the optical fiber 5 while converging.

  As shown in FIGS. 1 and 3 to 5, a second reflecting surface 16 is provided on the right side of the first lens surface 11 on the inner bottom surface 10 a of the first recess 10. The second reflecting surface 16 is configured only by the surface shape of the portion adjacent to the first lens surface 11 in the optical receptacle 2. More specifically, as shown in FIGS. 3 and 4, the second reflecting surface 16 is connected to the right end of the first lens surface 11 in a chord shape and has a rectangular shape in the bottom view. ing. As shown in FIG. 5, the second reflecting surface 16 is formed in an inclined plane having a predetermined second inclination angle θ [°] with respect to the lower end surface 2a. As the second inclination angle θ, a suitable angle may be set according to the irradiation direction of the monitor light M (in other words, the arrangement position of the light receiving element 8), the size of the light receiving surface of the light receiving element 8, and the like.

  Further, the central portion of the light emitting element 7 (in other words, the center of the laser light La) indicated by a two-dot chain line in FIG. 5 is second reflected with respect to the optical axis OA (1) on the first lens surface 11. It is arranged at a position shifted to the surface 16 side.

  As shown in FIGS. 1 and 5, the second reflecting surface 16 has a portion of the laser light La emitted from the light emitting element 7 other than a part of the laser light La incident on the first lens surface 11. Another part of the laser beam La is incident. The second reflection surface 16 uses the other part of the incident laser light La as the monitor light M having a predetermined reflectance that satisfies the so-called Fresnel formula by using Fresnel reflection. Reflect towards.

  Here, FIG. 7 shows a spot shape on the light receiving element 8 of the monitor light M reflected in this way. On the other hand, FIG. 6 shows a spot shape on the end surface 5a of the optical fiber 5 of the fiber coupled light Lc.

  According to the above configuration, the laser light La of the light-emitting element 7 can be split into the fiber coupling light Lc and the monitor light M by the first lens surface 11 and the second reflection surface 16, and is therefore accompanied by a monitor. Optical transmission can be realized with a simple and robust configuration. Specifically, since it is not necessary to provide a spectroscopic recess as shown in Patent Document 1, the mold shape can be simplified and the mechanical strength can be improved. Further, since the monitor light M is configured to be incident on the light receiving element 8 without being redirected on the optical path after the second reflecting surface 16, only the surface shape of the second reflecting surface 16 is selected. Thus, it is possible to easily design the optical path of the monitor light M adapted to the free arrangement position of the light receiving element 8.

  A reflective film made of a thin film of a metal (for example, Al, Ag, Au) having a high light reflectivity may be formed on the first reflective surface 14 and the second reflective surface 16 as necessary. However, if priority is given to reducing the number of parts, it is desirable to employ a configuration using only total reflection and Fresnel reflection as described above.

  In the present invention, various modifications as shown below may be adopted.

(First modification)
For example, the light intensity ratio between the fiber coupling light Lc and the monitor light M is such that a part of the laser light La incident on the first lens surface 11 and another part of the laser light La incident on the second reflecting surface 16. Can be adjusted by the beam cross-sectional area ratio (area ratio of the cross section perpendicular to the optical axis OA (1)). It can be adjusted by the amount.

  Therefore, when it is desired to increase the light intensity of the monitor light M compared to the case shown in FIG. 5, the central portion (two-dot chain line portion) of the light emitting element 7 is placed on the first lens surface 11 as shown in FIG. 8. What is necessary is just to arrange | position in the position away from the 2nd reflective surface 16 side with respect to upper optical axis OA (1).

(Second modification)
Further, as shown in FIGS. 9 and 10 (corresponding to the CC cross-sectional view of FIG. 9), the second reflecting surface 16 is directed to the light receiving element 8 side having a semicircular shape in the bottom view. You may form in an inclined concave curved surface.

  If comprised in this way, since the condensing function of the monitor light M can be provided to the 2nd reflective surface 16, the coupling | bonding of the monitor light M to the light receiving element 8 can be performed efficiently.

(Third Modification)
Furthermore, as shown in FIG. 11 and FIG. 12, it may be configured so as to be compatible with the multi-channel optical transmission with a monitor.

  In other words, in this modification, the photoelectric conversion device 3 includes a plurality of (12) light emitting elements 7 and light receiving elements 8 aligned in the direction perpendicular to the paper surface in FIG. In the present modification, the same number of optical fibers 5 as the light emitting elements 7 and the light receiving elements 8 are arranged in the same direction as the alignment direction of the light emitting elements 7 and the light receiving elements 8. In FIG. 11, each optical fiber 5 is attached to the optical receptacle 2 through a known attachment means in a state of being accommodated in a multi-core collective connector 19.

  Further, according to the configuration of the photoelectric conversion device 3 and the optical fiber 5, the optical receptacle 2 has an optical path between each light emitting element 7 and each optical fiber 5 and an optical path between each light emitting element 7 and each light receiving element 8. As shown in FIG. 11, the dimension in the direction perpendicular to the paper surface of FIG. 11 is larger than that of FIG. Further, the same number of lenses 11, 12 and second reflecting surfaces 16 as light emitting elements 7, optical fibers 5, and light receiving elements 8 are located at positions corresponding to light emitting elements 7, end face 5 a of optical fiber 5 and light receiving elements 8, respectively. It is formed one by one.

  According to this modification, the laser beam La for each light emitting element 7 is coupled to each light emitting element 7 on each first lens surface 11 and each second reflecting surface 16 corresponding to each light emitting element 7. Since the light can be split into the light Lc and the monitor light M, multi-channel optical transmission with a monitor can be realized with a simple and robust configuration, and a flexible design according to the arrangement position of the light receiving element 8 can be realized. It becomes possible.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the characteristics of the present invention.

  For example, an optical transmission body other than the optical fiber 5 such as an optical waveguide may be applied to the present invention.

DESCRIPTION OF SYMBOLS 1 Optical module 2 Optical receptacle 3 Photoelectric conversion apparatus 5 Optical fiber 5a End surface 6 Semiconductor substrate 7 Light emitting element 8 Light receiving element 11 1st lens surface 14 1st reflective surface 16 2nd reflective surface

Claims (6)

In the state where the light emitting element and the light receiving element for receiving the monitor light for monitoring the light emitted from the light emitting element are disposed between the photoelectric conversion device mounted on the substrate and the optical transmission body, the light emission An optical receptacle capable of optically coupling an element and the optical transmission body,
A first lens surface arranged so that a part of the light of the light emitting element is incident on the first surface of the optical receptacle body on the photoelectric conversion device side;
The optical receptacle main body has a predetermined first tilt angle with respect to the first surface on the second surface opposite to the first surface, and is incident on the first lens surface. A first reflecting surface that is arranged so that a part of the light reaches and reflects the reached part of the light;
An emission surface for emitting the part of the light reflected by the first reflection surface toward the optical transmission body;
On the first surface, the first lens surface is connected to the first lens surface, and is arranged so that a part of the light other than the part of the light of the light emitting element is incident thereon. The second reflection surface that reflects the other part of the light as the monitor light toward the light receiving element, and includes a top portion through which the optical axis passes and a chord-like portion surrounding the top portion. A part of the string-shaped portion of the first lens surface is formed in place of the string-shaped portion continuous to the top portion, and only the surface shape of the portion adjacent to the first lens surface in the optical receptacle body is provided. And a second reflecting surface that reflects the other part of the incident light as the monitor light toward the light receiving element only by total reflection or Fresnel reflection, and
The optical receptacle is characterized in that a central portion of the light emitting element is disposed at a position shifted toward the second reflecting surface with respect to the optical axis on the first lens surface. The optical receptacle according to claim 1, wherein the second reflecting surface has an inclined plane that forms a predetermined second inclination angle with respect to the first surface. The optical receptacle according to claim 1, wherein the second reflecting surface has a concave curved surface directed toward the light receiving element. The optical receptacle according to any one of claims 1 to 3, wherein the emission surface is a second lens surface that converges and emits the partial light. The first reflection surface is a total reflection surface that internally enters the part of light with an incident angle larger than a critical angle and totally reflects the part of the light incident on the first reflection surface. The optical receptacle according to claim 1. The optical receptacle according to any one of claims 1 to 5,
An optical module comprising the photoelectric conversion device according to claim 1.

Images