WO2020202692A1

WO2020202692A1 - Light source device and optical device

Info

Publication number: WO2020202692A1
Application number: PCT/JP2020/000887
Authority: WO
Inventors: 力山崎
Original assignee: 株式会社村田製作所
Priority date: 2019-04-03
Filing date: 2020-01-14
Publication date: 2020-10-08
Also published as: JP2022112520A

Abstract

A light source device 30 is provided with: a light source 20 that creates a plurality of mutually parallel light beams; and a plurality of cores 11 that corresponds to the plurality of light beams. Each core 11 transmits a light beam that is incident on an incident surface 11a from the light source 20 and emits the light beam from an emission surface 11b. Each core 11 has a longitudinal direction DL and a transverse direction DT perpendicular to the longitudinal direction DL; each core 11 has a refractive index distribution in which the refractive index decreases as the distance increases in the transverse direction DT from an optical axis OA that extends along the longitudinal direction DL and intersects with the incident surface 11a and the emission surface 11b. Each light beam is incident on the incident surface 11a at a location shifted from the optical axis OA in the transverse direction DT.　This configuration allows one or more light beams to be obliquely emitted.

Description

Light source device and optical device

The present invention relates to a light source device capable of emitting one or more light beams, and an optical device using such a light source device.

Conventionally, a multi-core optical fiber for optical communication having two cores in a clad has been disclosed (for example, Patent Document 1). Light enters each core along the longitudinal direction of the optical fiber, travels through the center of each core, and is emitted along the longitudinal direction of the optical fiber.

Japanese Patent No. 6258618 Special Table 2015-531861 International Publication No. 2018/159706 Japanese Unexamined Patent Publication No. 2012-137688

In the method of Patent Document 1, light is only emitted along the longitudinal direction of the optical fiber, and no reference is made to the emission direction of light.
An object of the present invention is to provide a light source device capable of emitting one or more light beams so as to be inclined. Another object of the present invention is to provide an optical device using such a light source device.

The light source device according to one aspect of the present invention includes a light source that generates a light beam and a light source.
An optical element that transmits a light beam incident on an incident surface from the light source and emits it from an emitting surface is provided.
The optical element has a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, extends along the longitudinal direction, and extends in the transverse direction from an optical axis intersecting the entrance surface and the emission surface. It has a refractive index distribution in which the refractive index decreases as the distance increases.
The light source is arranged at a position where the light beam is incident on the incident surface at a position shifted from the optical axis in the transverse direction.

The light source device according to another aspect of the present invention includes a light source that generates a plurality of light beams parallel to each other and a light source.
A plurality of optical elements provided corresponding to a plurality of light beams, and each optical element transmits a light beam incident on an incident surface from the light source and emits the light beam from the exit surface.
With
Each optical element has a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, extends along the longitudinal direction, and extends in the transverse direction from an optical axis intersecting the entrance surface and the emission surface. It has a refractive index distribution in which the refractive index decreases as the distance increases.
The light source is arranged at a position where each light beam is incident on the incident surface at a position shifted in the transverse direction from the optical axis.

The optical device according to another aspect of the present invention includes the above-mentioned light source device and a holder for holding a sample irradiated with a light beam emitted from the light source device.

According to the light source device according to the present invention, it is possible to emit one or a plurality of light beams so as to be inclined.

FIG. 1A is a perspective view showing an example of a light source device according to the first embodiment of the present invention. FIG. 1B is a cross-sectional view taken along the line XX in FIG. 1A and shows one aspect of the light beam path. FIG. 1C is a cross-sectional view taken along line XX in FIG. 1A, showing another aspect of the light beam path. FIG. 2A is an explanatory diagram showing the path of light rays in a core having a GI type refractive index distribution. FIG. 2B is a graph showing the refractive index distribution. It is explanatory drawing which shows the appearance that a plurality of light emitting parts are arranged in a 2 × 2 matrix in a light source, FIG. 3A shows an XY coordinate table of a light emitting part, and FIG. 3B shows a schematic perspective view. 4A is a side view showing an example of the dimensions of the core and the clad, FIG. 4B is a perspective view seen from the entrance surface side, and FIG. 4C is a perspective view seen from the exit surface side. FIG. 5A is a perspective view showing an example of the emission direction of the light beam emitted from the emission surface of each core. FIG. 5B is an explanatory diagram showing a light beam spot at the target. FIG. 5C is a graph showing the refractive indexes of the core and the clad. It is explanatory drawing which shows an example of the manufacturing method of an optical unit. It is a perspective view which shows an example of the light source apparatus which concerns on Embodiment 2 of this invention. It is a perspective view which shows another example of the light source apparatus which concerns on Embodiment 2 of this invention. FIG. 9A is a perspective view showing an example of the emission direction of the light beam when the refraction element is integrally provided on the emission surface. FIG. 9B is an explanatory diagram showing a light beam spot at the target. FIG. 10A is a perspective view showing an example of the emission direction of the light beam when the refracting element is provided apart from the emission surface. FIG. 10B is an explanatory diagram showing a light beam spot at the target. FIG. 11A is a configuration diagram showing an optical device according to a third embodiment of the present invention, and FIG. 11B is a perspective view thereof.

The optical element according to one aspect of the present invention includes a light source that generates a light beam and
An optical element that transmits the light beam incident on the incident surface from the light source along the optical axis and emits the light beam from the exit surface is provided.
The optical element has a longitudinal direction along the optical axis and a transverse direction orthogonal to the longitudinal direction, and the light extends along the longitudinal direction and intersects the incident surface and the emitting surface. It has a refractive index distribution in which the refractive index decreases as the distance from the axis increases in the transverse direction.
The light source is arranged at a position where the light beam is incident on the incident surface at a position shifted from the optical axis in the transverse direction.

According to this configuration, since the optical element has a refractive index distribution in which the refractive index decreases as the distance from the optical axis increases in the transverse direction, the trajectory of the light beam passing through the optical element is a curve in which the distance from the optical axis changes. Is shown. The light beam is incident on the incident surface at a position shifted in the transverse direction from the optical axis. This allows the optical element to emit a light beam so as to be inclined with respect to the optical axis.

The optical element according to another aspect of the present invention includes a light source that generates a plurality of light beams parallel to each other and a light source.
A plurality of optical elements provided corresponding to a plurality of light beams, and each optical element transmits a light beam incident on an incident surface from the light source and emits the light beam from the exit surface.
With
Each optical element has a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, extends along the longitudinal direction, and extends in the transverse direction from an optical axis intersecting the entrance surface and the emission surface. It has a refractive index distribution in which the refractive index decreases as the distance increases.
The light source is arranged at a position where each light beam is incident on the incident surface at a position shifted in the transverse direction from the optical axis.

According to this configuration, since each optical element has a refractive index distribution in which the refractive index decreases as the distance from the optical axis increases in the transverse direction, the trajectory of the light beam passing through the optical element changes in distance from the optical axis. Shows a curve. Each light beam is incident on the incident surface at a position shifted in the transverse direction from the optical axis. As a result, the light source device can emit a plurality of light beams so as to be inclined with respect to the optical axis.

Each light beam may be incident on the incident surface at a position shifted from the optical axis so as to approach each other along the transverse direction.

According to this configuration, each light beam diverges away from the optical axis when it is emitted from the exit surface.

Each light beam may be incident on the incident surface at a position shifted so as to move away from the optical axis along the transverse direction.

According to this configuration, when each light beam is emitted from the exit surface, it is focused once so as to approach the optical axis, then intersects the optical axis, and then diverges so as to move away from the optical axis.

The light source device may further include a holding unit that holds the plurality of optical elements.

According to this configuration, the holding unit can stably position a plurality of optical elements.

The holding portion may be a clad provided on the outer periphery of the plurality of optical elements and having a refractive index lower than that of the optical elements.

According to this configuration, the outer circumference of the optical element is protected, so that the light beam can travel stably in the core.

The light source may be embedded in the clad.

According to this configuration, the positioning accuracy between the light source and the optical element can be improved.

The locus of the light beam passing through the optical element shows a curve in which the distance from the optical axis changes, and the curve has an antinode whose tangent line is parallel to the optical axis and its tangent line to the optical axis. Including the inclined area that is inclined with respect to
The exit surface may be provided in the inclined region.

According to this configuration, the exit surface can emit a light beam in a direction inclined with respect to the optical axis.

The light source device may be further provided with a refracting element which is provided on or away from the emitting surface and changes the traveling direction of the light beam.

According to this configuration, the refracting element can change the traveling direction of the light beam to emit the light beam so as to diverge more from the optical axis.

The light source device may be further provided with a refracting element that is integrally provided on the exit surface and changes the traveling direction of the light beam.

The light source may be provided in contact with the incident surface of the optical element.

According to this configuration, the optical device can be miniaturized and the light utilization efficiency can be improved.

The light source may be a multi-emitter surface emitting laser.

According to this configuration, the optical device can be miniaturized.

The refractive index distribution may be a graded type in which the refractive index changes in a quadratic curve with respect to the distance from the optical axis.

According to this configuration, the trajectory of the light beam passing through the optical element changes in a sinusoidal shape.

According to this configuration, it is possible to emit a plurality of light beams so as to diverge from the optical axis and irradiate the sample.

(Embodiment 1)
FIG. 1A is a perspective view showing an example of the light source device 30 according to the first embodiment of the present invention. FIG. 1B is a cross-sectional view taken along the line XX in FIG. 1A and shows one aspect of the light beam path. FIG. 1C is a cross-sectional view taken along line XX in FIG. 1A, showing another aspect of the light beam path.

The light source device 30 includes an optical unit 10 including a plurality of cores 11 and a clad 12, and a light source 20. The core 11 functions as an optical element that transmits an optical beam. Here, the case where the four cores 11 are arranged in a 2 × 2 matrix will be illustrated.

The clad 12 is provided so as to be solidly filled on the outer circumference of each core 11, and functions as a holding portion for holding each core 11. The core 11 and the clad 12 can be made of a material transparent to light, for example, an inorganic material such as glass or quartz, or an organic material such as a synthetic resin, like a general optical fiber. The refractive index of the core 11 is generally designed to be greater than the refractive index of the clad 12. The clad 12 protects the outer circumference of the core 11 and contributes to the stable progress of light in the core 11, but it can be omitted if necessary.

Each core 11 has a longitudinal DL and a transverse DT orthogonal to the longitudinal DL. Each core 11 has an incident surface 11a on which light is incident and an exit surface 11b on which light is emitted. The entrance surface 11a and the exit surface 11b are arranged so as to face each other in the longitudinal direction DL. In the first embodiment, the entrance surface 11a and the exit surface 11b are parallel to the transverse direction DT. Each core 11 has an optical axis OA so as to extend along the longitudinal direction DL and intersect (for example, orthogonally) the entrance surface 11a and the exit surface 11b. In the first embodiment, the optical axis OA is an axis passing through the center of the entrance surface 11a and the center of the exit surface 11.

A light source 20 that generates a plurality of light beams parallel to each other is arranged in front of the incident surface 11a. As the light source 20, a multi-emitter surface emitting laser in which a plurality of light emitting units are arranged two-dimensionally, for example, a VCSEL (Vertical Cavity Surface Emitting Laser) or the like can be used. Here, a case where the light emitting portions of the light source 20 are arranged in a 2 × 2 matrix corresponding to the four cores 11 arranged in a 2 × 2 matrix to generate four light beams is illustrated.

The light source 20 may be provided apart from the incident surface 11a of the core 11, but may be provided in contact with the incident surface 11a. As a result, the positioning accuracy between the light source 20 and the core 11 can be improved, and the light source device 30 can be downsized.

The light source 20 is fixed on a substrate SB such as a printed wiring board and is electrically connected to a drive circuit (not shown). Below the clad 12, a skirt portion 12a that fits with the outer shape of the light source 20 is provided so as to extend to the substrate SB, and the light source 20 is embedded inside the skirt portion 12a. As a result, the positioning accuracy between the light source 20 and the core 11 is further improved. In addition, the airtightness and watertightness of the light source device 30 can be improved.

FIG. 2A is an explanatory diagram showing the path of light rays in the core 11 having a GI (Graded Index) type refractive index distribution. FIG. 2B is a graph showing the refractive index distribution. An optical element having a GI type refractive index distribution is also referred to as a GRIN lens. The core 11 has a refractive index distribution that decreases as it moves away from the optical axis OA in the transverse direction DT. That is, the refractive index in the core 11 is distributed in a quadratic curve with respect to the radius r from the optical axis OA, for example, in a parabolic shape, becomes the highest on the optical axis OA, and decreases as the radius r increases. Specifically, the refractive index n (r) in the core 11 is represented by the following equation (1). Here, n1 is the refractive index on the optical axis OA, √A is the gradient coefficient, and r is the radial position from the optical axis OA.

At this time, the light rays in the core 11 show a sinusoidal curve that changes periodically at the pitch P, and the node that approaches the optical axis OA and minimizes the distance from the optical axis OA for each length P / 2. , The belly that moves away from the optical axis OA and maximizes the distance from the optical axis OA appears repeatedly. The relationship of 2πP = LC × √A is established by using the length LC of the core 11.

Such a refractive index distribution may be extended to a higher-order function of second order or higher with respect to the radius r from the optical axis OA. The refractive index distribution in this case is represented by the following equation (2). Here, n _rn (n = 0, 2, 4, ..., 12) is a coefficient.

The individual light emitting parts of the light source 20 are arranged to face each other so as to have a one-to-one correspondence with the individual cores 11. As a result, the light beams emitted from the individual light emitting portions of the light source 20 are maintained parallel to the optical axis OA of the corresponding core 11 and are incident on the incident surface 11a as they are. When the light beam travels from the entrance surface 11a to the exit surface 11b inside the core 11, the main ray of the light beam shows a path in which the distance from the optical axis OA changes periodically at the pitch P. Here, the path of the light beam can be divided into two regions, that is, 1) a divergent region RD from the internode Q1 to the antinode Q2 and 2) a focusing region RC from the antinode Q2 to the internode Q1.

The path of such a light beam is uniquely determined according to the position where the light beam is incident on the incident surface 11a. As an example, as shown in FIG. 2A, focusing on a single light beam OB1, the light beam OB1 is incident on the incident surface 11a at a position shifted from the optical axis OA by a distance ΔD along the transverse direction DT. .. After passing through the antinode Q2 corresponding to the incident surface 11a, the light beam OB1 is inclined so as to approach the optical axis OA in the focusing region RC, and intersects the optical axis OA in the node Q1. Subsequently, when entering the divergence region RD, the optical beam OB1 passes through the optical axis OA and inclines so as to move away from the optical axis OA, and then gradually becomes parallel to the optical axis OA when approaching the ventral Q2. It becomes parallel when passing through the belly Q2. Similarly, the light beam OB1 travels periodically along a sinusoidal curve. The amplitude and tilt angle of these curves change with distance ΔD, but the positions of nodes Q1 and antinode Q2 do not.

In the example shown in FIG. 2A, the exit surface 11b of the core 11 is set in the range of the focusing region RC. In this case, when the light beam OB1 emits the exit surface 11b, the light beam OB1 inclines downward with respect to the optical axis OA, travels straight in the air, approaches the optical axis OA and intersects, and then the optical axis OA. It diverges away from.

Next, a case where the exit surface 11b of the core 11 is set within the range of the divergence region RD (for example, the position ZA in FIG. 2A) will be described. In this case, when the light beam OB1 emits the exit surface 11b, it is inclined upward with respect to the optical axis OA, travels straight in the air, and diverges so as to move away from the optical axis OA.

Next, a case where the exit surface 11b of the core 11 is set in the vicinity of the section Q1 will be described. Also in this case, when the light beam OB1 emits the exit surface 11b, it is inclined upward or downward with respect to the optical axis OA, travels straight in the air, and diverges away from the optical axis OA.

On the other hand, a case where the exit surface 11b of the core 11 is set to the belly Q2 or its vicinity will be described. In this case, when the light beam OB1 emits the exit surface 11b, it emits in parallel or substantially parallel to the optical axis OA, and travels straight in the air in parallel or substantially parallel to the optical axis OA.

Therefore, by setting the exit surface 11b of the core 11 to either the focusing region RC, the divergence region RD, or the vicinity of the node Q1, that is, the light beam path is set in the inclined region inclined with respect to the optical axis OA. When the light beam OB1 emits the exit surface 11b, it emits at an angle with respect to the optical axis OA and diverges so as to move away from the optical axis OA.

The emission position and emission angle of the light beam OB1 are periodically repeated at the pitch P. Therefore, the core 11 can be miniaturized by setting the exit surface 11b in the range from the antinode Q2 corresponding to the incident surface 11a to the next antinode Q2.

Returning to FIG. 1, in the example shown in FIG. 1B, each light beam emitted from the light source 20 is incident on each incident surface 11a at a position shifted from the optical axis OA so as to approach each other along the transverse direction DT. ing. Further, the exit surface 11b is set in the range from the first focusing region RC to the first divergence region RD counting from the incident surface 11a. Therefore, as shown in FIG. 2A, the light beam that has passed through the incident surface 11a is inclined so as to approach the optical axis OA in the first focusing region RC after passing through the antinode Q2 corresponding to the incident surface 11a. When the exit surface 11b is emitted, it is inclined with respect to the optical axis OA and travels straight so as to move away from the optical axis OA. Therefore, as shown in FIG. 1B, the light beams emitted from the exit surface 11b diverge as they are away from each other.

In the example shown in FIG. 1C, each light beam emitted from the light source 20 is incident on each incident surface 11a at a position shifted away from the optical axis OA along the transverse direction DT. Further, the exit surface 11b is set in the range from the first focusing region RC to the first divergence region RD counting from the incident surface 11a. Therefore, as shown in FIG. 2A, the light beam that has passed through the incident surface 11a is inclined so as to approach the optical axis OA in the first focusing region RC after passing through the antinode Q2 corresponding to the incident surface 11a. When the exit surface 11b is emitted, it is inclined with respect to the optical axis OA and travels straight so as to move away from the optical axis OA. Therefore, as shown in FIG. 1C, the light beams emitted from the exit surface 11b once approach each other and intersect with each other, but then diverge so as to move away from each other.

As described above, in the present invention, each light beam is incident on the incident surface 11a at a position shifted from the optical axis OA along the transverse direction DT. This makes it possible to emit a plurality of light beams so as to diverge from the optical axis OA.

FIG. 3 is an explanatory view showing how a plurality of light emitting parts are arranged in a 2 × 2 matrix in the light source 20, FIG. 3A shows an XY coordinate table of the light emitting parts, and FIG. 3B shows a schematic perspective view.

As an example, a total of 4 XY coordinates are defined by combining two X coordinates (-0.40 mm, -0.10 mm) and two Y coordinates (0.15 mm, 0.35 mm), for a total of 4 The light emitting parts are arranged. At this time, the pitch in the X direction between the light emitting portions is 0.3 mm, and the pitch in the Y direction is 0.2 mm.

In the present embodiment, the case where the four cores 11 are arranged two-dimensionally is illustrated, but the present invention can also be applied when two, three or five or more cores 11 are arranged two-dimensionally. Is. In this case, the light emitting portion of the light source 20 is also provided so as to correspond to the number and arrangement of the cores 11. Further, the arrangement spacing of the light emitting portions may be other than 0.20 mm and 0.30 mm.

Further, in the present embodiment, the case where the core 11 is columnar is illustrated, but the present invention can also be applied when the core 11 is prismatic, for example, square columnar, hexagonal columnar, octagonal columnar or the like.

4A is a side view showing an example of the dimensions of the core 11 and the clad 12, FIG. 4B is a perspective view seen from the entrance surface 11a side, and FIG. 4C is a perspective view seen from the exit surface 11b side. is there. The columnar core 11 and clad 12 have a length of 1.325 mm. The core 11 has an outer diameter of 0.4 mm. The clad 12 has an outer diameter of 1.6 mm. The cores 11 are arranged so that the optical axes have a pitch of 0.5 mm. The distance from the exit surface 11b to the target TG is 1.675 mm.

FIG. 5A is a perspective view showing an example of the emission direction of the light beam emitted from the emission surface 11b of each core 11. FIG. 5B is an explanatory diagram showing a light beam spot at the target TG. FIG. 5C is a graph showing the refractive indexes of the core 11 and the clad 12.

Similar to FIG. 1B, the four light beams pass through the four cores 11 and are emitted from the exit surface 11b and diverged so as to move away from each other. At this time, the inclination angles (θx, θy) of each light beam with respect to the optical axis OA are, for example, (−5.8 °, 8.6 °), (5.8 °, 8.6 °), (5. 8 °, -8.6 °), (5.8 °, -8.6 °).

As shown in FIG. 5B, the four light beams form four spots in the target TG. The pitch in the X direction between the spots is about 0.70 mm, and the pitch in the Y direction is about 0.85 mm. The inter-spot pitch at the target TG is magnified about 2.3 times in the X direction and about 4.3 times in the Y direction as compared with the pitch between the light emitting portions.

As shown in FIG. 5C, the central refractive index of the core 11 is, for example, 1.45250, which decreases in a quadratic curve. The refractive index of the clad 12 is, for example, 1.42813. The numerical values shown in FIGS. 4 and 5 are merely examples, and other numerical values can be adopted.

FIG. 6 is an explanatory diagram showing an example of a manufacturing method of the optical unit 10. As shown in FIG. 6A, the container 50 is filled with the raw material 51 of the clad 12. Next, as shown in FIG. 6B, a plurality of nozzles NZ for supplying the raw material 52 of the core 11 are inserted into the raw material 51, and the opening of the nozzle NZ is positioned near the bottom of the container 50. As an example, when manufacturing the core 11 arranged in a 2 × 2 matrix, the nozzle NZ is also arranged in a 2 × 2 matrix. Next, as shown in FIG. 6C, the raw material 52 is sent out while pulling up each nozzle NZ. At this time, the pulling speed of the nozzle NZ and the delivery amount of the raw material 52 are adjusted so that the raw material 52 remaining in the raw material 51 becomes cylindrical.

Next, as shown in FIG. 6D, after the nozzle NZ has been pulled up, leave it for a predetermined time. As a result, the raw material 51 and the raw material 52 are gradually cured while being mixed with each other. When completely cured, the raw material 51 becomes a clad material 51a, and the raw material 52 becomes a core material 52a. At this time, the mixing ratio of the

raw materials

51 and 52 changes from the outside to the inside of the core material 52a, and a desired refractive index distribution can be obtained by appropriately setting the production conditions.

As the

raw materials

51 and 52, an uncured fluid, for example, a synthetic resin before curing can be used, and for example, a silicone resin, an acrylic resin, an epoxy resin, a polyimide resin, a polyolefin resin, a polynorbornene resin, etc. can be used, and after curing, Are selected so that their epoxies are different from each other.

Next, as shown in FIG. 6E, the clad material 51a and the core material 52a are taken out from the container 50 and processed by machining such as cutting or chemical treatment such as etching to form the optical unit 10 shown in FIG. Is obtained.

In the above description, the GI type core 11 whose refractive index distribution changes continuously has been illustrated, but the present invention also describes the SI (Step Index) type core 11 whose refractive index distribution changes stepwise. Can be applied as well.

(Embodiment 2)
FIG. 7 is a perspective view showing an example of the light source device 30 according to the second embodiment of the present invention. In the present embodiment, the refraction element 15 is provided on the exit surface of the core 11.

The light source device 30 includes an optical unit 10 including a plurality of cores 11 and a clad 12 and a light source 20 as in the first embodiment. Since the details of the light source device 30 are the same as those in the first embodiment, duplicate description will be omitted.

The refracting element 15 has a function of changing the traveling direction of the light beam emitted from the exit surface of the core 11. For example, when the light beam is emitted from the exit surface of the core 11 at an angle inclined by about 40 degrees with respect to the optical axis, when passing through the refracting element 15, the light beam is inclined at an angle of about 70 degrees with respect to the optical axis. Is configured to be emitted from the exit surface of the refracting element 15. The refracting element 15 is made of, for example, a hemispherical transparent material. Such an inclination angle can be set to a desired value by adjusting the height of the refracting element 15, the radius of curvature, the refractive index, the distance between the core 11 and the refracting element 15, and the like, thereby increasing the degree of freedom in optical design. Become.

FIG. 8 is a perspective view showing another example of the light source device 30 according to the second embodiment of the present invention. The refracting element 15 is made of, for example, a conical transparent material, and has a function of changing the traveling direction of the light beam emitted from the exit surface of the core 11. Such a refracting element 15 can also increase the emission angle on the exit surface, which increases the degree of freedom in optical design.

The above-mentioned refracting element 15 may be joined as a separate component on the exit surface of the core 11, may be integrally formed at the time of manufacturing the core 11, or may be formed as a separate component apart from the exit surface of the core 11. It may be installed.

In addition to the hemispherical shape and the conical shape, the above-mentioned refracting element 15 has other shapes such as a semi-elliptical shape, a hyperboloid shape, a parabolic shape, a parabolic shape, or a triangular pyramid shape or a quadrangular pyramid shape. , Hexagonal pyramid or other polygonal pyramid.

FIG. 9A is a perspective view showing an example of the emission direction of the light beam when the refraction element 15 is integrally provided on the emission surface. FIG. 9B is an explanatory diagram showing a light beam spot at the target TG. The dimensions of the core 11 and clad 12 are the same as those described in FIGS. 4 and 5. The distance between the core 11 and the refracting element 15 is zero.

The four light beams pass through the four cores 11 and are emitted from the exit surface, and are diverged by the refracting element 15 so as to be further away from each other. At this time, the inclination angles (θx, θy) of each light beam with respect to the optical axis OA are, for example, (-13.0 °, 19.5 °), (13.0 °, 19.5 °), (-13). 0.0 °, -19.5), (13.0 °, -19.5 °). Therefore, the angular magnification of the refracting element 15 is about 2.25 (= 13.0 ° / 5.8 °).

As shown in FIG. 9B, the four light beams form four spots in the target TG. The pitch in the X direction between the spots is about 1.16 mm, and the pitch in the Y direction is about 1.50 mm. The pitch between spots in the target TG is magnified about 3.9 times in the X direction and about 7.5 times in the Y direction as compared with the pitch between the light emitting parts.

FIG. 10A is a perspective view showing an example of the emission direction of the light beam when the refraction element 15 is provided apart from the emission surface. FIG. 10B is an explanatory diagram showing a light beam spot at the target TG. The dimensions of the core 11 and clad 12 are the same as those described in FIGS. 4 and 5. The distance between the core 11 and the refracting element 15 is 0.2 mm.

The four light beams pass through the four cores 11 and are emitted from the exit surface, and are diverged by the refracting element 15 so as to be further away from each other. At this time, the inclination angles (θx, θy) of each light beam with respect to the optical axis OA are, for example, (-14.0 °, 19.5 °), (14.0 °, 19.5 °), (-14). (0.0 °, -19.5 °), (14.0 °, -19.5 °). Therefore, the angular magnification of the refracting element 15 is about 2.4 (= 14.0 ° / 5.8 °).

As shown in FIG. 10B, the four light beams form four spots in the target TG. The pitch in the X direction between the spots is about 1.2 mm, and the pitch in the Y direction is about 1.4 mm. The pitch between spots in the target TG is magnified about 4.0 times in the X direction and about 7.0 times in the Y direction as compared with the pitch between the light emitting parts.

When the refracting elements 15 are provided apart from the exit surface, if the inclination angles (θx, θy) of each light beam shown in FIG. 9A are the same, the refracting elements 15 are moved in the X direction so as to be away from each other. Shift by 0.03 mm in the Y direction and 0.03 mm in the Y direction.

(Embodiment 3)
FIG. 11A is a configuration diagram showing an optical device 100 according to a third embodiment of the present invention, and FIG. 11B is a perspective view thereof. The optical device 100 according to the present embodiment operates as an observation device for observing the sample SA.

The optical device 100 includes a light source device 30 including the above-mentioned optical unit 10 and a light source 20, a holder 110 that holds the sample SA, a detection element 120 that optically detects the sample SA, and the like. The holder 101 is formed of a transparent material through which light can pass, and is configured as a substrate on which a large number of well WLs capable of holding a liquid are formed. The detection element 120 is composed of an image sensor such as a CMOS image sensor (CIS), for example. A condenser lens 121 is provided in close contact with the front of the detection element 120.

For example, an Au-deposited thin film is provided on the surface of the holder 110, and when a light beam is irradiated, photothermal conversion occurs in which the temperature rises locally due to the plasmon effect. Sample SA is a liquid in which a large number of plastic beads are dispersed. Irradiation of the light beam causes the liquid to vaporize locally to generate microbubbles, which allows the beads to accumulate. The state of accumulation is detected by the detection element 120.

In the present embodiment, each light beam is incident on the incident surface of the core 11 at a position shifted in the transverse direction from the optical axis. As a result, the light source device 30 can emit a plurality of light beams so as to diverge from the optical axis and irradiate the sample SA.

As an example, when using an optical unit 10 in which four cores 11 are arranged in a 2 × 2 matrix, one light source 20 is used and four light beams are arranged in a 2 × 2 matrix. It becomes possible to simultaneously irradiate and detect a plurality of sample SAs in the four wells WL.

In the present embodiment, the case where the four cores 11 are arranged two-dimensionally is illustrated, but the present invention can also be applied when two, three or five or more cores 11 are arranged two-dimensionally. Is. In this case, the light emitting portion of the light source 20 and the well WL of the holder 101 are also provided so as to correspond to the number and arrangement of the cores 11.

By using the light source device 30 according to the present invention in this way, it becomes possible to irradiate a plurality of sample SAs at the same time. As a result, the optical device 100 can be downsized and the number of parts can be reduced.

Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various modifications and modifications are obvious to those skilled in the art. It should be understood that such modifications and modifications are included therein, as long as they do not deviate from the scope of the invention according to the appended claims.

The present invention is extremely useful in industry because it is possible to realize a light source device capable of emitting one or a plurality of light beams so as to be inclined.

10 Optical unit 11 Core

11a Incident surface

11b Exit surface 12 Clad 12a Skirt part 15 Refractive element 20 Light source DL Longitudinal DT Transverse direction OA Optical axis Q1 Section Q2 Abdominal RC Focusing area RD Divergence area 30 Light source device 100 Optical device 110 Holder 120 element

Claims

A light source that generates a light beam and
An optical element that transmits a light beam incident on an incident surface from the light source and emits it from an emitting surface is provided.
The optical element has a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, extends along the longitudinal direction, and extends in the transverse direction from an optical axis intersecting the entrance surface and the emission surface. It has a refractive index distribution in which the refractive index decreases as the distance increases.
The light source is a light source device in which the light beam is arranged at a position where the light beam is incident on the incident surface at a position shifted from the optical axis in the transverse direction.
A light source that generates multiple light beams parallel to each other,
A plurality of optical elements provided corresponding to the plurality of light beams, and each optical element transmits the light beam incident on the incident surface from the light source and emits the light beam from the exit surface. With,
Each optical element has a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, extends along the longitudinal direction, and extends in the transverse direction from an optical axis intersecting the entrance surface and the emission surface. It has a refractive index distribution in which the refractive index decreases as the distance increases.
The light source is a light source device in which each light beam is arranged at a position where each light beam is incident on the incident surface at a position shifted in the transverse direction from the optical axis.
The light source device according to claim 2, wherein each light beam is incident on the incident surface at a position shifted from the optical axis so as to approach each other along the transverse direction.
The light source device according to claim 2, wherein each light beam is incident on the incident surface at a position shifted from the optical axis so as to move away from each other along the transverse direction.
The light source device according to claim 2, further comprising a holding unit for holding the plurality of optical elements.
The light source device according to claim 5, wherein the holding portion is provided on the outer periphery of the plurality of optical elements and is a clad having a refractive index lower than that of the optical elements.
The light source device according to claim 6, wherein the light source is embedded in the clad.
The locus of the light beam passing through the optical element shows a curve in which the distance from the optical axis changes, and the curve has an antinode whose tangent line is parallel to the optical axis and its tangent line to the optical axis. Including the inclined area that is inclined with respect to
The light source device according to claim 1 or 2, wherein the exit surface is provided in the inclined region.
The light source device according to claim 1 or 2, further comprising a refracting element which is provided on or away from the exit surface and changes the traveling direction of the light beam.
The light source device according to claim 1 or 2, further comprising a refracting element integrally provided on the exit surface and changing the traveling direction of the light beam.
The light source device according to claim 1 or 2, wherein the light source is provided in contact with the incident surface of the optical element.
The light source device according to claim 1 or 2, wherein the light source is a multi-emitter surface emitting laser.
The light source device according to claim 1 or 2, wherein the refractive index distribution is a graded type in which the refractive index changes in a quadratic curve with respect to the distance from the optical axis.
The light source device according to any one of claims 1 to 13.
An optical device comprising a holder for holding a sample to be irradiated with a light beam emitted from the light source device.
The optical device according to claim 14, further comprising a detection element that optically detects the sample.