JP5920813B2 - Optical module - Google Patents

Description

  The present invention relates to an optical module, and more particularly to an optical module suitable for controlling the light traveling direction of a light emitting element.

  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 via an optical transmission body such as an optical fiber or an optical waveguide.

  In this type of optical module, an optical element for controlling the traveling direction of light emitted from the light emitting element is mounted as a means for optically coupling the light emitting element and the end face of the optical transmission body.

  FIG. 17 shows an example of an optical module equipped with such a conventional optical element.

  As shown in FIG. 17, the optical module 1 includes a light emitting element 2 such as a VCSEL that emits (emits) laser light, and an optical element 3 that is disposed to face the light emitting element 2. The optical element 3 is integrally formed of a translucent material such as a transparent resin material (for example, polyetherimide).

  As shown in FIG. 17, the optical element 3 has a lens surface 4 as an incident surface disposed at a position facing the light emitting element 2, and this lens surface 4 has a convex surface facing the light emitting element 2 side. It is a convex lens surface. As shown in FIG. 17, the optical axis OA of the lens surface 4 is arranged (positioned) on the same straight line as the central light beam Ls of the laser light L (light beam) emitted from the light emitting element 2.

  As shown in FIG. 17, the laser beam L emitted from the light emitting element 2 is incident on such a lens surface 4. The lens surface 4 collimates the incident laser light L and advances it into the optical element 3.

  In addition, as shown in FIG. 17, a light separation surface 5 is disposed at a position facing the lens surface 4 on the traveling direction (transmission direction) side of the laser light L. Laser light L (collimated light) transmitted through the lens surface 4 is incident on the light separation surface 5. The light separation surface 5 separates the incident laser light L.

  Further, as shown in FIG. 17, the light is separated at the position facing the light separation surface 5 on the first direction (right side in FIG. 17) orthogonal to the incident direction of the laser light L with respect to the surface 5. Surface 6 is arranged. A part of the laser light L (hereinafter referred to as communication light Lc) separated by the light separation surface 5 is vertically incident on the emission surface 6. Then, the emission surface 6 emits the incident communication light Lc to the outside of the optical element 3 (to the right in FIG. 17). In addition, as shown in FIG. 17, the end surface 7a of the optical transmission body 7 is arranged at a position facing the emission surface 6 on the emission direction side of the communication light Lc. The communication light Lc emitted from the emission surface 6 is combined and used for optical communication via the optical transmission body 7.

Here, the light separation surface 5 will be described in detail. As shown in FIG. 17, the light separation surface 5 is a planar shape arranged on the extension line of the optical axis OA of the lens surface 4 so as to be orthogonal to the optical axis OA. The transmission surface 51 is provided. The first light L ₁ (light beam) including the central ray Ls of the laser light L that has reached the light separation surface 5 from the lens surface 4 side is perpendicularly incident on the transmission surface 51. Then, the transmission surface 51, the first light L ₁ incident, and transmits to the outside of the optical element 3 without the refraction. The transmitted light in such a transmission surface 51 is detected by a light receiving element (not shown) as a monitor light for monitoring (monitoring) the communication light Lc (intensity and light amount) emitted from the emission surface 6, for example. Sometimes it is done.

  As shown in FIG. 17, the light separation surface 5 has a first total reflection surface 52 connected to the transmission surface 51 on the first direction side. The first total reflection surface 52 is formed on an inclined plane that is inclined to the opposite side (upward in FIG. 17) from the lens surface 4 as it goes toward the first direction. The inclination angle of the inclined plane is 45 ° clockwise in FIG. 17 with reference to the optical axis OA of the lens surface 4 (0 °), in other words, 45 in the counterclockwise direction in FIG. It is °.

The first total reflection surface 52 has a second light L ₂ (light beam) adjacent to the first light L ₁ of the laser light L reaching the light separation surface 5 on the first direction side. Is larger than the critical angle from the relationship between the refractive index n of the optical element 3 material corresponding to the wavelength of the laser beam L and the refractive index of the air layer (= 1), and the incident angle θi (> sin ⁻¹ (1 / n)). The first total reflection surface 52 totally reflects the second light L ₂ incident as part of the communication light Lc toward the exit surface 6. At this time, the second light reflecting direction L ₂ becomes perpendicular to the incident direction.

  Further, as shown in FIG. 17, the light separation surface 5 is adjacent to the transmission surface 51 in the second direction (leftward in FIG. 17) opposite to the first direction (not connected). Two total reflection surfaces 53 are provided. The second total reflection surface 53 is formed on the same inclined plane as the first total reflection surface 52. The second total reflection surface 53 and the transmission surface 51 are connected by a step surface 54 that is orthogonal to the transmission surface 51.

In such a second total reflection surface 53, the third light L ₃ (light beam) adjacent to the _first light L ₁ of the laser light L reaching the light separation surface 5 on the second direction side. However, the incident angle is larger than the critical angle. Then, the second total reflection surface 53 totally reflects (reflects at right angles) the incident third light L ₃ in the same direction as the second light L ₂ as a part of the communication light Lc.

  Moreover, as a prior art document relevant to such an optical module 1, the following patent document 1 can be mentioned, for example. The optical module described in Patent Document 1 includes light reflecting means for reflecting a part of light emitted from the photoelectric conversion element for the purpose of attenuation of light quantity.

Japanese Patent No. 4610478

However, conventionally, the first total reflection surface 52 and the second total reflection surface 53 have a gap corresponding to the step surface 54 in the direction orthogonal to the reflection direction of the reflected light L ₂ and L _3. since that was placed, communication light Lc emitted from the emission surface 6 (combined light and the second light L ₂ and the third light L ₃₎ is in a cross section perpendicular to the traveling direction, the second light L ₂ And the third light L ₃ have a region where the light intensity is significantly reduced (gap) reflecting the stepped surface 54.

  When such communication light Lc is used for optical communication, in particular, the beam shape should be a single spot and the light intensity distribution should be a single mountain distribution having a single peak intensity at the center. When is important (for example, when optical transmission is performed using a single mode optical fiber), adversely affecting the optical characteristics has been a problem.

  Therefore, the present invention has been made in view of such problems, and can optimize the beam shape and intensity distribution of the reflected light separated from the transmitted light, thereby improving the optical characteristics. It is an object of the present invention to provide an optical module capable of satisfying the requirements.

In order to achieve the above-described object, a feature of the optical module according to claim 1 of the present invention includes a light emitting element that emits light and an optical element that controls a traveling direction of the light emitted from the light emitting element. The optical element includes a light incident surface on which the light from the light emitting element is incident, an incident surface that propagates the incident light to the inside of the optical element as collimated light, and the collimated light on the incident surface. The collimated light is incident on the side of the traveling direction of the light, and the collimated light is incident thereon. The light separating surface separates the incident collimated light, and the light separating surface is orthogonal to the incident direction of the collimated light with respect to the surface. A part of the light separated by the light separation surface is incident and an emission surface for emitting the part of the incident light. Light separation surface, the first light is incident, including a central ray in the collimated light, a planar transmission surface perpendicular to the incident direction of the collimated light to be transmitted without the refracting a first light the incident And is connected to the transmission surface on the first direction side, and is inclined to the opposite side to the incident surface toward the first direction side. Second light adjacent to the light on the first direction side is incident at an incident angle larger than a critical angle, and the incident second light is totally reflected toward the exit surface as the partial light. The first total reflection surface is connected to the transmission surface on the second direction side opposite to the first direction, and is inclined toward the incident surface side toward the second direction side. Formed and Third light adjacent to the first light in the mate light on the second direction side is incident at an incident angle larger than a critical angle, and the incident third light is used as the part of the light. 2 is formed by a second total reflection surface that totally reflects in the same direction as the light reflection direction, the end of the first total reflection surface on the transmission surface side, and the second total reflection surface the end portion of the transmitting side, in that it is connected to Oite the transmitting surface at the same position to each other in the second light and the third direction orthogonal to the direction of reflection of light.

According to the first aspect of the present invention, the planar transmission surface perpendicular to the incident direction of the collimated light that transmits the incident first light without refraction is formed, and the first total reflection surface is formed. end and a Oite the transmitting surface at the same position to each other in a direction perpendicular to the direction of reflection of the second light and the third light transmitting surface side of the end portion and the second total reflection surface of the transmissive surface side of the By connecting them to each other, the second light and the third light emitted from the emission surface can exhibit a centrally symmetric single spot shape integrated with each other in a cross section perpendicular to the traveling direction. Since a centrally symmetric intensity distribution having a peak intensity at the part can be shown, the beam shape and intensity distribution of the reflected light separated from the transmitted light can be improved. The surface shape of the transmission surface can be a flat shape and can be formed into a shape suitable for the straight transmission of the central ray of the first light. Further, since the light separation surface can be formed only by surfaces that effectively function optically (transmission surface, first total reflection surface, and second total reflection surface), the optical element is molded using a mold. In this case, the mold releasability can be ensured satisfactorily by suppressing the contact area between the mold and the optical element molded product.

The feature of the optical module according to claim 2, in claim 1, the pre-Symbol first total reflection surface and the second total reflection surface, the second light and the third light, the It is in the point arrange | positioned so that it may totally reflect in the direction orthogonal to the incident direction of the said 1st light with respect to a transmissive surface.

  According to the second aspect of the present invention, the light of the light emitting element can be configured to be separated using the straight transmission and the right angle reflection, so that the design and the dimensional accuracy measurement can be simplified. Can do.

Furthermore, the optical module according to claim 3 is characterized in that, in claim 1 or claim 2 , the incident surface is formed on a lens surface for collimating light from the light emitting element.

And according to this invention concerning Claim 3 , collimated light can be obtained simply and reliably.

  According to the present invention, it is possible to optimize the beam shape and intensity distribution of the reflected light separated from the transmitted light, thereby improving the optical characteristics.

The block diagram which shows embodiment of the optical module which concerns on this invention The top view which shows the optical element in the optical module of FIG. The bottom view which shows the optical element in the optical module of FIG. Configuration diagram of optical module showing first modified example Bottom view of optical element showing second modification Configuration diagram showing optical module with conventional product 1 The figure which shows the pattern image of the light intensity distribution on the 1st measurement surface about the optical module which mounts the conventional product 1 The figure which shows the pattern image of the light intensity distribution on the 2nd measurement surface about the optical module which mounts the conventional product 1 The figure which shows the pattern image of the light intensity distribution on the 3rd measurement surface about the optical module which mounts the conventional product 1 The graph which shows the light intensity distribution of the X / Y-axis direction on the 1st-3rd measurement surface about the optical module which mounts the conventional product 1. The figure which shows the pattern image of the light intensity distribution on the 2nd measurement surface about the optical module which mounts the conventional product 2 The figure which shows the pattern image of the light intensity distribution on the 3rd measurement surface about the optical module which mounts the conventional product 2 The graph which shows the light intensity distribution of the X / Y-axis direction on the 1st-3rd measurement surface about the optical module which mounts the conventional product 2. The figure which shows the pattern image of the light intensity distribution on the 2nd measurement surface about the optical module carrying the product of this invention The figure which shows the pattern image of the light intensity distribution on the 3rd measurement surface about the optical module carrying the product of this invention The graph which shows the light intensity distribution of the X / Y-axis direction on the 1st-3rd measurement surface about the optical module carrying the product of this invention. Configuration diagram showing a conventional optical module (optical module equipped with the conventional product 2)

  Hereinafter, an embodiment of an optical module according to the present invention will be described with reference to FIGS. 1 to 16, focusing on differences from the conventional configuration shown in FIG.

  For the sake of convenience, portions having the same or similar basic configuration as those in the related art will be described using the same reference numerals.

  FIG. 1 is a configuration diagram showing an optical module 1 in the present embodiment. FIG. 2 is a plan view of the optical element 3 in the optical module 1 shown in FIG. FIG. 3 is a bottom view of the optical element 3 in the optical module 1 shown in FIG.

As shown in FIG. 1, the optical module 1 according to the present embodiment collimates the laser light L emitted from the light emitting element 2 on the lens surface 4 (spherical surface or aspherical surface) as an incident surface, and the inside of the optical element 3. The light separating surface 5, the second light L ₂ that is totally reflected by the first total reflection surface 52, the third light L ₁ that is transmitted through the transmission surface 51, and the third light L _2. The point of separation into three light beams with the third light L ₃ totally reflected by the total reflection surface 53 is the same as in the conventional case.

However, the optical module 1 in the present embodiment has a characteristic difference from the conventional optical module 1 in the specific configuration of the first total reflection surface 52 and the second total reflection surface 53. That is, as shown in FIG. 1, in the present embodiment, the first total reflection surface 52 and the second total reflection surface 53 are not on the same plane as in the conventional configuration, but on the same plane. It is shifted from the top in the reflection direction of the reflected lights L ₂ and L ₃ . Further, as shown in FIG. 1, there is no step surface 54 (see FIG. 17) connecting the both surfaces 53, 51 as in the prior art between the second total reflection surface 53 and the transmission surface 51, Both surfaces 53 and 51 are directly connected. Further, as shown in FIG. 1, the end of the first total reflection surface 52 on the transmission surface 51 side (the connecting portion with the transmission surface 51, that is, the left end), and the second total reflection surface 53 on the transmission surface 51 side. Are disposed at the same position in a direction (vertical direction in FIG. 1) perpendicular to the reflection direction of the reflected lights L ₂ and L ₃ . In other words, the end of the first total reflection surface 52 on the transmission surface 51 side and the end of the second total reflection surface 53 on the transmission surface 51 side are parallel to the reflection direction of the reflected light L ₂ and L _3. Are included in the same virtual plane. Since the configuration other than this is basically the same as the conventional one, the details are omitted.

Then, according to the optical module 1 configured in this way, the second total reflection surface 53 totally reflects the second light L ₂ totally reflected by the first total reflection surface 52 in FIG. it is possible to form the optical path, such as the upper end is in contact in Figure 1 of the third light L ₃ reflected. Thus, the second light L ₂ and the third light L ₃ (communication light Lc) emitted from the emission surface 6 are centrally symmetric single spot shapes integrated with each other in a cross section perpendicular to the traveling direction. (Substantially elliptical shape) can be exhibited, and a centrally symmetric intensity distribution (a distribution close to a Gaussian distribution) having a peak intensity at the center can be shown. However, the axis of symmetry of the spot shape and intensity distribution at this time, the tangent of the second light L ₂ and the third light L ₃ after total reflection (straight line perpendicular to the traveling direction of the light included in the tangent plane) It corresponds to. Such second light L ₂ and third light L ₃ can exhibit good optical characteristics (for example, optical coupling efficiency) in optical communication. Moreover, according to this embodiment, since the light separation surface 5 can be formed only by the surfaces 51 to 53 that function effectively optically, when the optical element 3 is resin-molded using a mold, By suppressing the contact area between the mold and the optical element molded product, it is possible to ensure good release properties.

  Various modifications as described below can be applied to the present invention.

(First modification)
For example, as shown in FIG. 4, when the monitoring light receiving element 11 is mounted on the same circuit board 10 as the light emitting element 2, the first light L ₁ is located at a position in the transmission direction side of the first light L ₁ with respect to the transmission surface 51. , the first light L ₁ may be arranged optical surface 12 for guiding to the light receiving element 11. In addition, although the optical surface 12 in FIG. 4 is comprised by the two total reflection surfaces 12a and 12b, it does not need to be limited to such a structure. Of course, the optical surface 12 may be integrated into the optical element 3 as one of the surfaces of the optical element 3.

(Second modification)
In addition, as shown in FIG. 5, the present invention is configured to support multi-channel optical transmission with a monitor by providing a plurality of lens surfaces 4 so as to correspond to a plurality of light emitting elements 2. Also good. In FIG. 5, each lens surface 4 is orthogonal to both the incident direction of the first light L ₁ with respect to the transmission surface 51 and the reflection directions of the reflected lights L ₂ and L _{3 on} the total reflection surfaces 52 and 53 ( They are aligned in the vertical direction in FIG.

  Next, in this embodiment, the optical cross-sectional shape and the light intensity distribution are evaluated for the optical module 1 on which the three samples of the conventional product 1, the conventional product 2 and the product of the present invention are mounted as the optical element 3, respectively. went. This evaluation was performed based on the result of the light intensity simulation on the measurement surface of the light intensity set perpendicular to the optical path at a plurality of different locations on the optical path of the laser light L of the light emitting element 2. In addition, the structure of the conventional product 1 is provided with only the total reflection surface 50 without having the transmission surface 51 as shown in FIG. The configuration of the conventional product 2 is as shown in FIG. Furthermore, the structure of the product of the present invention is as shown in FIGS.

  Hereinafter, the evaluation results for the optical module 1 on which the respective samples are mounted will be sequentially described together with the results of the light intensity simulation.

[Evaluation of optical module with conventional product 1]
As shown in FIG. 6, the conventional product 1 has first to third measurement surfaces S ₁ and S 3 as light intensity measurement surfaces perpendicular to the traveling direction (optical path) of the laser light of the light emitting element 2. _2, was set _{S 3.}

Specifically, the first measurement surface S ₁ was set as an XY coordinate plane perpendicular to the optical axis OA of the lens surface 4 on the optical path between the light emitting element 2 and the lens surface 4. However, at the first measuring surface S _1, X-axis direction is taken in the lateral direction in FIG. 6, also, Y-axis direction is taken in the direction perpendicular to the paper surface in the figure, further, the origin is on the extension of the optical axis OA I took it. The second measuring surface S ₂ is the position of the output side of the reflected light Lr for emission surface 6 was set as perpendicular XY coordinate plane in the traveling direction of the reflected light Lr. However, in the second measuring surface S _2, X-axis direction is taken in the vertical direction in FIG. 6, also, Y-axis direction is taken in the direction perpendicular to the paper surface in the figure, further, origin of the luminous flux cross-section of the reflected light Lr The position corresponding to the center point was taken. Further, a third measuring surface S ₃ is an extension of the optical axis OA of the lens surface 4 in the external optical element 3 was set as perpendicular XY coordinate plane to the optical axis OA. However, in the third measurement surface S _3, X-axis direction is taken in the lateral direction in FIG. 6, also, Y-axis direction is taken in the direction perpendicular to the paper surface in the figure, further, the origin is on the extension of the optical axis OA I took it.

The evaluation of the light beam cross-sectional shape is performed by obtaining the pattern image of the light intensity distribution as the light intensity simulation result for each measurement surface S ₁ , S ₂ , S ₃ and then evaluating the shape of the acquired pattern image. Went by.

In addition, the evaluation of the light intensity distribution is performed for each measurement surface S ₁ , S ₂ , S ₃ as a light intensity simulation result using the X-axis coordinate value as a variable (hereinafter, light intensity distribution in the X-axis direction). And a graph of a light intensity distribution (hereinafter referred to as a light intensity distribution in the Y-axis direction) using the Y-axis coordinate value as a variable, and then evaluating the characteristics of the acquired graph. Went by.

In such an assumption, the pattern image of the light intensity distribution at the first measuring surface S on ₁ became that shown in Fig. Note that a change in tone in the pattern image indicates a change in light intensity. The pattern image of the light intensity distribution in the second on the measurement surface S ₂ became that shown in Fig. Further, the pattern image of the light intensity distribution in the third on the measurement surface S ₃ became that shown in Fig. Furthermore, the graph of the light intensity distribution in the X-axis direction is as shown in FIG. 10A, and the light intensity distribution graph in the Y-axis direction is as shown in FIG. In FIG. 10A, the horizontal axis is the distance from the origin on the X axis (that is, the X axis coordinate value) [mm], and the vertical axis is the light intensity distribution [W / mm ² ]. In FIG. 10B, the horizontal axis is the distance from the origin on the Y axis (that is, the Y-axis coordinate value) [mm], and the vertical axis is the light intensity distribution [W / mm ² ].

[Evaluation]
As shown in FIGS. 8 and 10, in the conventional product 1, the cross-sectional shape of the reflected light Lr can be a perfect circular shape that is substantially the same as the cross-sectional shape of the light beam before total reflection (see FIG. 7). Since the light intensity distribution can be a distribution close to the Gaussian distribution, it can be said that such reflected light Lr is ideal when only ordinary optical coupling is considered. However, as shown in FIG. 9, the conventional product 1 cannot obtain transmitted light at all, and thus cannot cope with the intended use (monitor) in the present invention.

[Evaluation for optical module with conventional product 2]
Next, as shown in FIG. 17, the conventional product 2 also has the first to third points in the same manner as the conventional product 1 at positions corresponding to the measurement surfaces S ₁ , S ₂ , and S ₃ of the conventional product 1. Three measurement surfaces S ₁ , S ₂ , S ₃ were set.

Then, in the optical module 1 equipped with a conventional product 2, the pattern image of the light intensity distribution at the first measuring surface S on ₁ became similar to FIG. The pattern image of the light intensity distribution in the second on the measurement surface S ₂ became that shown in FIG. 11. Further, the pattern image of the light intensity distribution in the third on the measurement surface S ₃ became those shown in FIG. 12. Furthermore, on each measurement surface S ₁ , S ₂ , S ₃ , the graph of the light intensity distribution in the X-axis direction is as shown in FIG. 13A, and the graph of the light intensity distribution in the Y-axis direction is As shown in FIG. The definitions of the X axis and the Y axis in each measurement surface S ₁ , S ₂ , S ₃ are the same as in the case of the conventional product 1.

[Evaluation]
As shown in FIG. 12, in the conventional product 2, the transmitted light L ₁ can be obtained by the presence of the transmission surface 51. However, as shown in FIG. 11, the cross-sectional shape of the reflected light L ₂ , L ₃ (communication light Lc) is divided into two in the X-axis direction with a long gap in the Y-axis direction, A single spot shape cannot be exhibited. Further, as shown in FIG. 13A, the light intensity distribution in the X-axis direction has two peaks, and at the same time, the light intensity distribution in the Y-axis direction becomes almost zero as shown in FIG. 13B. This is a great departure from the ideal Gaussian distribution. Such characteristics are caused by the presence of the step surface 54 that separates the first total reflection surface 52 and the second total reflection surface 53, so that the end of the first total reflection surface 52 on the transmission surface 51 side is This is because the second total reflection surface 53 is arranged on the opposite side of the lens surface 4 in the direction orthogonal to the reflection direction of the reflected light L ₂ and L ₃ from the end on the transmission surface 51 side. Such reflected lights L ₂ and L ₃ are unsuitable for proper optical communication as pointed out as conventional problems.

[Evaluation of optical module equipped with the product of the present invention]
Next, as shown in FIG. 1, in the product of the present invention, the first to third points are positioned at positions corresponding to the measurement surfaces S ₁ , S ₂ and S ₃ of the conventional product 1 in the same manner as the conventional product 1. Three measurement surfaces S ₁ , S ₂ , S ₃ were taken.

Then, in the optical module 1 equipped with the present invention product, the pattern image of the light intensity distribution at the first measuring surface S on ₁ became similar to FIG. The pattern image of the light intensity distribution in the second on the measurement surface S ₂ became those shown in FIG. 14. Further, the pattern image of the light intensity distribution in the third on the measurement surface S ₃ became those shown in FIG. 15. Furthermore, on each measurement surface S ₁ , S ₂ , S ₃ , the light intensity distribution graph in the X-axis direction is as shown in FIG. 16A, and the light intensity distribution graph in the Y-axis direction is 16 (b). The definitions of the X axis and the Y axis in each measurement surface S ₁ , S ₂ , S ₃ are the same as in the case of the conventional product 1.

[Evaluation]
As shown in FIG. 14, in the product of the present invention, the cross-sectional shape of the reflected light L ₂ and L ₃ is a single line symmetric (centrosymmetric) with respect to an axis of symmetry parallel to the Y axis passing through the origin of the X axis. As shown in FIG. 16A, the light intensity distribution in the X-axis direction is a line having a unique peak intensity at the center (origin) near the ideal Gaussian distribution, as shown in FIG. The distribution was symmetric (centrosymmetric). Such a characteristic is that the end of the first total reflection surface 52 on the transmission surface 51 side and the end of the second total reflection surface 53 on the transmission surface 51 side reflect the reflected light L ₂ and L ₃ . This is because they are arranged at the same position in a direction orthogonal to the direction. Such reflected light L _2, L ₃ may correspond fully to the correct optical communications.

  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, the incident surface need not be limited to the collimation lens surface 4, and may be formed on a plane on which laser light is vertically incident, for example. However, in that case, it is necessary to configure so that collimated light is incident on the incident surface from the beginning, for example, by interposing a collimation lens between the light emitting element 2 and the incident surface.

DESCRIPTION OF SYMBOLS 1 Optical module 2 Light emitting element 3 Optical element 4 Lens surface 5 Light separation surface 6 Outgoing surface 51 Transmission surface 52 1st total reflection surface 53 2nd total reflection surface

Claims (3)

An optical module comprising: a light emitting element that emits light; and an optical element that controls a traveling direction of the light emitted from the light emitting element,
The optical element is
An incident surface on which light from the light emitting element is incident, and the incident light travels as collimated light into the optical element;
A light separating surface that is disposed at a position facing the incident surface on the traveling direction side of the collimated light, the collimated light is incident, and the incident collimated light is separated;
A part of the light separated by the light separation surface is incident on the light separation surface at a position opposed to the light separation surface in a predetermined first direction orthogonal to the incident direction of the collimated light. And a light exit surface for emitting a part of the light,
The light separation surface is
A plane-shaped transmission surface perpendicular to the incident direction of the collimated light that is incident on the first light including the central ray in the collimated light and transmits the incident first light without refraction ;
It is connected to the transmission surface on the first direction side, and is inclined to the opposite side to the incident surface toward the first direction side, and is formed on the first light in the collimated light. Second light adjacent on the first direction side is incident at an incident angle larger than a critical angle, and the incident second light is totally reflected toward the exit surface as the partial light. Total reflection surface of
The transmission surface is connected on the second direction side opposite to the first direction, and is inclined to the incident surface side toward the second direction side, and the collimated light in the collimated light Third light adjacent to the first light on the second direction side is incident at an incident angle larger than a critical angle, and the incident third light is used as the partial light of the second light. A second total reflection surface that totally reflects in the same direction as the reflection direction,
The transmission surface side end of the first total reflection surface and the transmission surface side end of the second total reflection surface are in the reflection direction of the second light and the third light. optical module characterized in that it is connected to Oite the transmitting surface at the same position with each other in the orthogonal direction. First total reflection surface and the second total reflection surface before SL is totally reflects the second light and the third light, in a direction perpendicular to the incident direction of the first light relative to the transmitting surface The optical module according to claim 1, wherein the optical module is arranged to be The optical module according to claim 1 , wherein the incident surface is formed on a lens surface that collimates light from the light emitting element .