KR102188411B1 - Optical assembly manufacturing method and optical assembly - Google Patents

Abstract

The optical assembly 10A has a red LD 11, a green LD 12, and a blue LD 13. Each of the red LD11, the green LD12, and the blue LD13 is mounted on the main surface 30a of the base member 30 via each of the submounts 21 to 23. The collimating lens 41 collimates the red laser light L _R from the red LD 11, and the collimating lens 42 collimates the green laser light L _G from the green LD 12, and collimates The lens 43 collimates the blue laser light L _B from the blue LD 13. The collimating lenses 41 to 43 are mounted on the main surface 30a via the sub-base members 51 to 53. The optical axes of the laser beams L _R , L _G and L _B are at substantially the same height with respect to the main surface 30a.

Description

A manufacturing method of an optical assembly, and an optical assembly TECHNICAL FIELD [OPTICAL ASSEMBLY MANUFACTURING METHOD AND OPTICAL ASSEMBLY]

The present invention relates to a method of manufacturing an optical assembly, and to an optical assembly.

Patent Literature 1 discloses a technology related to an optical scanning type image display device that displays an image by two-dimensional scanning of a beam of intensity according to an image signal. In this image display device, the first scanning unit and the second scanning unit scan the light flux emitted from the light source unit. Further, a half mirror is provided on the optical path between the first and second scanning portions, and the intensity and timing of the light beam scanned by the first scanning portion and reflected by the half mirror is detected by the light detection portion. The first reflecting unit and the second reflecting unit are disposed at the position of the image plane formed by the light beam scanned by the second scanning unit, and the first reflecting unit and the second reflecting unit respectively reflect the luminous flux scanned by the second scanning unit. do. The optical path of the luminous flux scanned by the second scanning unit and reflected by the first reflecting unit and the second reflecting unit, respectively, and reflected by the half mirror is the same as the optical path of the luminous flux scanned by the first scanning unit and reflected by the half mirror. It is incident on the light detection unit as an optical path.

Patent Document 2 discloses a technology related to a light source device and a head mounted display. The light source device includes a green laser diode, a blue laser diode, a red laser diode, and a dichroic prism that selectively transmits and refracts light therefrom. The green laser diode has the largest amount of heat generated in the light source device and has a large radiator. The green laser diode is provided at a position facing the exit port with the dichroic prism therebetween. The width of the radiator is formed to be narrower than the width from the outside of the blue laser diode to the outside of the red laser diode.

In Patent Document 3, a technique related to a multi-wavelength light source device is disclosed. The multi-wavelength light source device mounts a plurality of laser diode (LD) chips in a coaxial module, and condenses each emitted light to one point by a single condensing lens. A multi-wavelength light source device includes a light source, a condensing means, and a light guiding means. The light source includes a plurality of light emitting points for emitting light. The condensing means condenses a plurality of lights emitted from a plurality of light emitting points. The light guiding means propagates so that a plurality of lights from a plurality of light-emitting points condensed by the light condensing means overlap and mix with each other.

Patent Document 4 discloses a technology related to a light source device having a light-emitting element such as a light-emitting diode. This light source device includes a light emitting element portion, a light collecting portion, and a multiplexing portion. The light-emitting element unit mounts a plurality of light-emitting elements on a chip, and independently controls light emission of each light-emitting element through an external terminal. In the condensing part, by fitting with the fitting hole provided in the lens stopper, the spherical lens is held close to the light-emitting part by contacting or facing the light-emitting element, and the light emitted from the light-emitting element is spread by a parallel beam of light before spreading. Direction is converted. The combining unit has a dichroic mirror and an aperture, combines parallel beams of light incident from the condensing unit, and selects and emits paraxial rays having excellent parallelism.

Patent Document 1: Japanese Patent Laid-Open No. 2011-227379 Patent Document 2: Japanese Patent Laid-Open No. 2011-171535 Patent Document 3: Japanese Patent Laid-Open No. 2011-066028 Patent Document 4: Japanese Patent Laid-Open No. 2006-013127

2. Description of the Related Art Recently, liquid crystal displays have been widely spread, and technology development for the application of liquid crystal displays to mobile devices is in progress. On the other hand, a display using an LD light source is superior in low power consumption, high precision, and versatility compared to white LEDs used for backlights of liquid crystal displays. For this reason, it is being studied to apply a display using an LD light source to a small projector, a head mounted display, a head-up display, and the like. The LD light source employed in such a display has a plurality of LDs constituting three primary colors of light such as red LD, green LD, and blue LD. Clear image quality is obtained by overlapping a plurality of laser beams output from this LD light source with strength and weakness.

However, unlike a general light source such as LED, in the LD light source, the beam expansion angle is narrow, for example, about 10°×20°. For this reason, it is necessary to align the optical axes of each laser light emitted from each of the red LD, green LD, and blue LD, which is a major disadvantage to the spread of displays using LD light sources.

The present invention has been made in view of such a problem, and provides a method of manufacturing an optical assembly, and an optical assembly capable of accurately adjusting the optical axes of each laser light emitted from each of red LD, green LD, and blue LD. The purpose.

The manufacturing method of an optical assembly according to an embodiment of the present invention is a manufacturing method of an optical assembly that combines and outputs red, green, and blue laser light, and includes a first wavelength among three wavelength regions of red, green, and blue. A first step of mounting a first laser diode that emits the first laser light on the main surface of the base member so that the first laser light included in the region is projected to the first projection point, and three wavelength regions A second laser diode that emits a second laser light so that the second laser light included in the second wavelength region is projected to a second projection point whose height based on the main surface of the base member is the same as the first projection point. The second step of mounting on the main surface of the base member, and the third laser light included in the third wavelength region of the three wavelength regions, have the same height with respect to the main surface of the base member as the first and second projection points. Before or after the third step and the third step of mounting a third laser diode that emits a third laser light on the main surface of the base member so as to be projected to the third projection point, the first laser light is transmitted, 2 A fourth step of mounting a first wavelength filter that reflects the laser light on the main surface of the base member so that the second projection point approaches the first projection point, and the first and second laser beams are transmitted, and the third laser And a fifth step of mounting a second wavelength filter that reflects light on the main surface of the base member so that the third projection point approaches the first projection point.

In addition, the optical assembly according to one embodiment of the present invention is an optical assembly that combines and outputs red, green, and blue laser light, and is included in a first wavelength region among three wavelength regions of red, green, and blue. The first laser light is emitted, the first laser diode mounted on the main surface of the base member through the first submount, and the second laser light included in the second wavelength region of the three wavelength regions are emitted, 2 The second laser diode mounted on the main surface of the base member through the submount and the third laser light included in the third wavelength region among the three wavelength regions are emitted, and the main surface of the base member through the third submount The third laser diode mounted on the image and the first laser light are collimated, and the first collimating lens mounted on the main surface of the base member through the first sub-base member and the second laser light are collimated. A second collimating lens mounted on the main surface of the base member via the second sub-base member, and a third collimating lens mounted on the main surface of the base member by collimating the third laser light and passing through the third sub-base member A mate lens is provided, and the optical axes of the first to third laser beams are at substantially the same height with respect to the main surface of the base member.

According to the manufacturing method of the optical assembly and the optical assembly according to the present invention, the optical axes of each laser light emitted from each of red LD, green LD, and blue LD can be precisely adjusted to each other.

1 is a perspective view showing a configuration of an optical assembly according to a first embodiment of the present invention.
2 is a top view schematically showing a first step of a method for manufacturing an optical assembly.
3 is a top view schematically showing a second step of the method for manufacturing an optical assembly.
4 is a top view schematically showing a third step of the method for manufacturing an optical assembly.
5 is a top view schematically showing a fourth step of a method for manufacturing an optical assembly.
6 is a top view schematically showing a fifth step of the method for manufacturing an optical assembly.
7 is a perspective view showing the appearance of the optical module according to the second embodiment.
8 is a perspective view illustrating an internal configuration of the optical module shown in FIG. 7 by separating the cap.
9 is a perspective view showing an external appearance of an optical module according to a third embodiment.
10 is a perspective view illustrating an internal configuration of the optical module shown in FIG. 9 by separating the glass cap.
Fig. 11(a) is a top view of the optical module, and Fig. 11(b) is a side view of the optical module.
12 is a perspective view showing a configuration of an optical assembly as a fourth embodiment.
13 is a diagram illustrating an optical module in which a reflective member is added to an optical assembly according to a third embodiment.
14 is a perspective view showing the appearance of another optical module according to the third embodiment.
15 is a perspective view showing the internal configuration of a part of the optical module (ceramic package).
Fig. 16 is a perspective view showing a configuration of an optical assembly as a fifth embodiment.
17 is a perspective view showing a configuration of an optical module according to a fifth embodiment.
18 is a top view schematically showing a third step of the method for manufacturing an optical assembly of the fifth embodiment.
19 is a top view schematically showing a fifth step of the method for manufacturing an optical assembly of the fifth embodiment.
Fig. 20 is a perspective view showing a configuration of an optical assembly as a sixth embodiment.
Fig. 21 is a perspective view showing a configuration of an optical assembly as a seventh embodiment.
Fig. 22 is a top view showing the configuration of an optical assembly as an eighth embodiment.
23 is a top view showing the configuration of an optical assembly as a modification of the eighth embodiment.

Hereinafter, a method of manufacturing an optical assembly according to the present invention and an embodiment of the optical assembly will be described in detail with reference to the accompanying drawings. In addition, in the description of the drawings, the same reference numerals are assigned to the same elements, and duplicate descriptions are omitted.

(First embodiment)

1 is a perspective view showing the configuration of an optical assembly 10A according to a first embodiment of the present invention. The optical assembly 10A of the present embodiment may combine and output the red laser light L _R , the green laser light L _G , and the blue laser light L _B. As shown in Fig. 1, the optical assembly 10A of the present embodiment includes a red LD 11, a green LD 12, and a blue LD 13, a first submount 21, and a second submount 22. ), a third submount 23, and a base member 30. The base member 30 has a flat main surface 30a.

The red LD 11 is the first LD in the present embodiment, and the laser light (first laser light) L included in the red wavelength region (first wavelength region) among the three wavelength regions of red, green, and blue _R is emitted. The red LD 11 is mounted on the first submount 21 and is mounted on the main surface 30a of the base member 30 via the first submount 21. The red LD 11 emits a red laser light L _R along the optical axis along the main surface 30a. The wavelength of the red laser light L _R is, for example, 640 nm.

The green LD 12 is the second LD in the present embodiment, and emits a laser light (second laser light) L _G included in the green wavelength region (second wavelength region) of the three wavelength regions. The green LD 12 is mounted on the second submount 22, and is mounted on the main surface 30a of the base member 30 via the second submount 22. The green LD 12 emits a green laser light L _G along the optical axis along the main surface 30a. In this embodiment, the emission direction of the green laser light L _G from the green LD 12 is at right angles to the emission direction of the red laser light L _R from the red LD 11. The wavelength of the green laser light L _G is, for example, 535 nm.

The blue LD 13 is the third LD in this embodiment, and emits a laser light (third laser light) contained in a blue wavelength region (third wavelength region) among the three wavelength regions. The blue LD 13 is mounted on the third submount 23 arranged and arranged on the side of the second submount 22, and passes through the third submount 23 to the main surface of the base member 30 ( It is mounted on 30a). In this embodiment, the emission direction of the blue laser light L _B from the blue LD 13 is at right angles to the emission direction of the red laser light L _R from the red LD 11, and from the green LD 12 It is parallel to the emission direction of the green laser light L _G. The wavelength of the blue laser light L _B is, for example, 440 nm.

In this embodiment, the height H _R of the laser light emission point of the red LD 11 based on the main surface 30a of the base member 30, the height H _G of the laser light emission point of the green LD 12, and The heights of the submounts 21 to 23 are set so that the heights H _B of the laser light emission points of the blue LD 13 are substantially equal to each other. That is, the optical axes of the laser beams L _R , L _G , and L _B are at substantially the same height with respect to the main surface 30a of the base member 30.

As a constituent material of the submounts 21 to 23, a material having a coefficient of thermal expansion close to that of the semiconductor material constituting the LDs 11 to 13, for example, AlN, SiC, Si, diamond, or the like is suitable. Further, each of the LDs 11 to 13 may be fixed to each of the submounts 21 to 23 by, for example, AuSn, SnAgCu, or Ag paste.

1, the optical assembly 10A includes a first collimating lens 41, a second collimating lens 42, a third collimating lens 43, a first sub-base member 51, and The 2 sub-base member 52, the third sub-base member 53, the first wavelength filter 61, the second wavelength filter 62, the fourth sub-base member 54, and the fifth sub-base member 55 ) Is further provided.

The first collimating lens 41 is optically coupled to the light exit end surface of the red LD 11, and collimates (parallelizes) the red laser light L _R emitted from the red LD 11. The first collimating lens 41 is mounted on the first sub-base member 51, and is mounted on the main surface 30a of the base member 30 via the first sub-base member 51.

The second collimating lens 42 is optically coupled to the light exit cross section of the green LD 12 and collimates the green laser light L _G emitted from the green LD 12. The second collimating lens 42 is mounted on the second sub-base member 52, and is mounted on the main surface 30a of the base member 30 via the second sub-base member 52.

The third collimating lens 43 is optically coupled to the light exit end face of the blue LD 13 and collimates the blue laser light L _B emitted from the blue LD 13. The third collimating lens 43 is mounted on the third sub-base member 53 arranged and arranged on the side of the second sub-base member 52, and passes through the third sub-base member 53 to the base member ( It is mounted on the main surface 30a of 30).

The optical axes of each of the collimating lenses 41 to 43 and the optical axes of each of the LDs 11 to 13 are adjusted to substantially coincide with each other. As an example, when the thickness of the submounts 21 to 23 is 0.15 mm and the height of the laser light emission point of LDs 11 to 13 is 0.1 mm, the height of the laser light emission point based on the main surface 30a is It becomes 0.25mm. In this case, when, for example, BK7 lenses with a diameter of 0.5 mm are used as the collimating lenses 41 to 43, the height of the optical axis of the collimating lenses 41 to 43 is 0.25 mm. Accordingly, the heights of the optical axes of the collimating lenses 41 to 43 and the heights of the optical axes of the LDs 11 to 13 substantially match.

The first wavelength filter 61 is a multilayer film filter formed on a glass substrate, for example, and is mounted on the main surface 30a of the base member 30 via the fourth sub-base member 54. One surface of the first wavelength filter 61 is optically coupled to the first collimating lens 41, and the other surface of the first wavelength filter 61 is optically coupled to the second collimating lens 42. Are combined. The first wavelength filter 61 transmits the red laser light L _R collimated by the first collimating lens 41, and transmits the green laser light L _G collimated by the second collimating lens 42. Reflect. The optical axis of the red laser light L _R transmitted through the first wavelength filter 61 and the optical axis of the green laser light L _G reflected by the first wavelength filter 61 are adjusted to substantially coincide with each other.

The second wavelength filter 62 is a multilayer film filter formed on a glass substrate, for example, and is mounted on the main surface 30a of the base member 30 via the fifth sub-base member 55. One surface of the second wavelength filter 62 is optically coupled to the other surface of the first wavelength filter 61, and the other surface of the second wavelength filter 62 is a third collimated lens. It is optically combined with (43). The second wavelength filter 62 includes the red laser light L _R and the green laser light L _G arriving from the first wavelength filter 61 (that is, the red laser light L collimated by the first collimating lens 41 ). _R , and the green laser light L _G collimated by the second collimated lens 42 are transmitted, and the laser light L _B collimated by the third collimated lens 43 is reflected. The optical axes of the red laser light L _R and the green laser light L _G transmitted through the second wavelength filter 62 and the blue laser light L _B reflected by the second wavelength filter 62 are adjusted to substantially coincide with each other. .

In addition, the height of each center position of the first wavelength filter 61 and the second wavelength filter 62 based on the main surface 30a is the laser light L _R , L _G , and L based on the main surface 30a It is preferable that it is substantially the same as the height of the optical axis of _B.

In addition, each of the collimating lenses 41 to 43 and the wavelength filters 61 to 62 is fixed to the sub-base members 51 to 55 by, for example, Ag paste or solder. The material constituting the sub-base members 51 to 55 is preferably a material having a thermal expansion coefficient close to that of the collimating lenses 41 to 43 and wavelength filters 61 to 62 on which they are mounted, such as glass. Alternatively, the sub-base members 51 to 55 may be made of ceramic or metal. The area of the mounting surface of the sub-base members 51 to 55 is the area in which ultraviolet curable resin in the amount necessary to fix the collimating lenses 41 to 43 and the wavelength filters 61 to 62 on which they are mounted can be applied, eg For example, it is preferably about 0.3 to 0.5 square millimeters.

In the optical assembly 10A having the above configuration, each of the red laser light L _R , the green laser light L _G and the blue laser light L _B from each of the red LD 11, green LD 12 and blue LD 13 It is emitted. These laser beams are collimated when passing through the first collimating lens 41, the second collimating lens 42, and the third collimating lens 43, respectively. Then, the red laser light L _R and the green laser light L _G are combined by the first wavelength filter 61, and this combined light and the blue laser light L _B are combined by the second wavelength filter 62. The combined light consisting of the red laser light L _R , the green laser light L _G and the blue laser light L _B is emitted to the outside of the optical assembly 10A along a predetermined optical axis.

Subsequently, a method of manufacturing the optical assembly 10A according to the present embodiment will be described. 2 to 6 are top views schematically showing each step of the manufacturing method of the optical assembly 10A.

First, as shown in Fig. 2, while the red LD 11 is mounted on the main surface 30a of the base member 30 via the first submount 21, the first collimating lens 41 Is mounted on the main surface 30a via the first sub-base member 51 (first step). Further, in this step, the red LD 11 and the first collimating lens 41 are formed so that the red laser light L _R is projected on the first projection point P1 located on the virtual plane H1 perpendicular to the main surface 30a. To place.

Specifically, first, the red LD 11 is mounted on the first submount 21 and fixed using a conventional die bonding method. Then, the first collimating lens 41 is fixed on the first sub-base member 51 while emitting the red LD 11. At this time, the vertical position of the first collimating lens 41 is adjusted so that the optical axis of the red laser light L _R is substantially parallel to the main surface 30a. In one embodiment, an ultraviolet curing resin is applied to the first sub-base member 51 and the thickness is secured, while the first collimating lens 41 is adsorbed with a collet, etc. Just adjust it. Thereby, the inclination angle of the optical axis of the red laser light L _R with respect to the main surface 30a can be adjusted. For example, an imaging device such as a CCD is disposed on a virtual plane separated by a predetermined distance (for example, 1 m) from the base member 30 and a virtual plane further (for example, 2 m) away from the virtual plane, and a red laser The vertical position of the first collimating lens 41 may be adjusted so that the position of the projection point of the light L _R coincides with the horizontal position of the main surface 30a of the base member 30. Moreover, since the red laser light L _R is transmitted through the first collimating lens 41, the beam of light is substantially parallel light, and it is possible to observe the projection pattern even at a position several meters apart. After passing through the above process, the ultraviolet curing resin is cured to fix the first collimating lens 41.

Next, as shown in FIG. 3, while the green LD 12 is mounted on the main surface 30a of the base member 30 via the second submount 22, the second collimating lens 42 ) Is mounted on the main surface 30a via the second sub-base member 52 (second step). In this step, the green LD 12 and the second collimating lens 42 are disposed so that the green laser light _LG is projected onto the second projection point P2 located on the virtual plane H1. The height of the second projection point P2 based on the main surface 30a of the base member 30 is the same as the height of the first projection point P1 based on the main surface 30a.

Specifically, first, the green LD 12 is mounted on the second submount 22 and fixed using a conventional die bonding method. In addition, the alignment mirror (70) has a vertical reflecting surface to the main surface (30a), that the reflecting surface is to achieve a angle of 45 ° to the optical axis of the red laser light L _R, the phase of the green laser light L _G optical axis To place. Then, the green LD 12 is made to emit light. At this time, the green laser light L _G is projected onto the virtual plane H1. Subsequently, while emitting the green LD 12, the upper and lower positions of the second collimating lens 42 are adjusted by the same method as in the first step. At this time, the height of the second projection point P2 of the green laser light L _G based on the main surface 30a is the same as the height of the first projection point P1 of the red laser light L _R based on the main surface 30a. do. In addition, at this point in time, it is not necessary to match the positions of the first and second projection points P1 and P2 in a direction parallel to the main surface 30a. After passing through the above process, the ultraviolet curable resin on the second sub-base member 52 is cured, and the second collimating lens 42 is fixed to the second sub-base member 52.

Subsequently, as shown in FIG. 4, while the blue LD 13 is mounted on the main surface 30a of the base member 30 via the third submount 23, the third collimating lens 43 ) Is mounted on the main surface 30a via the third sub-base member 53 (third step). In this step, the blue LD 13 and the third collimating lens 43 are disposed so that the blue laser light L _B is projected onto the third projection point P3 located on the virtual plane H1. The height of the third projection point P3 based on the main surface 30a of the base member 30 is the same as the height of the first projection point P1 based on the main surface 30a. Further, in this step, the blue LD 13 and the third collimating lens 43 may be disposed so that the positions of the second projection point P2 and the third projection point P3 substantially coincide with each other.

Specifically, first, the blue LD 13 is mounted on the third submount 23 and fixed using a conventional die bonding method. Further, the alignment mirror 70 is disposed on the optical axis of the blue laser light L _B so that its reflective surface forms an angle of 45° with respect to the optical axis of the red laser light L _R. Then, the blue LD 13 is made to emit light. At this time, the blue laser light L _B is projected onto the virtual plane H1. Subsequently, while emitting the blue LD 13, the upper and lower positions of the third collimating lens 43 are adjusted by the same method as in the first step. At this time, the height of the third projection point P3 of the blue laser light L _B based on the main surface 30a is the same as the height of the first projection point P1 of the red laser light L _R based on the main surface 30a. also and at the same time, the third projection that matches the position of P3, with a green laser of claim 2, the projection of the light L _G and the substantially center position of P _2. After passing through the above steps, the ultraviolet curable resin on the third sub-base member 53 is cured, and the third collimating lens 43 is fixed to the third sub-base member 53.

Subsequently, as shown in FIG. 5, the first wavelength filter 61 is mounted on the main surface 30a of the base member 30 (fourth step). At this time, the angle of the first wavelength filter 61 is adjusted so that the second projection point P2 of the green laser light L _G approaches (preferably substantially coincides with the first projection point P1 of the red laser light L _R ). .

On Specifically, first, a first wavelength filter (61) was placed on the green optical axis of laser light L _G, to reflect the green laser light L _G from the first wavelength filter 61, a projection plane (virtual plane H1) Project. And, by adjusting the swing angle and the inclination angle of the first wavelength filter 61, the second projection point P2 of the green laser light L _G is close to the first projection point P1 of the red laser light L _R. Let it. As an example, if the angle of the first wavelength filter 61 is adjusted so that the green laser light L _G is incident on these CCDs by using an imaging device such as a CCD used to adjust the red laser light L _R in the first step again. do. Further, preferably, the second projection point P2 should just match the first projection point P1. At this time, by adjusting the swing angle of the first wavelength filter 61, the vertical position of the second projection point P2 (position in the normal direction of the main surface 30a) changes, and the inclination angle of the first wavelength filter 61 The left and right positions (positions in the direction along the main surface 30a and the virtual plane H1) fluctuate by adjusting. The first wavelength filter 61, a first projection point also changes the position of P1, however, the red laser light L _R and the green laser light L _G, each of the projection points of the adjustment, the red laser beam L _R of P1, swing P2 matches There must be an angle and an angle of inclination. After passing through the above process, the ultraviolet curable resin on the fourth sub-base member 54 is cured, and the first wavelength filter 61 is fixed to the fourth sub-base member 54.

Subsequently, as shown in FIG. 6, the second wavelength filter 62 is mounted on the main surface 30a of the base member 30 (5th step). At this time, the angle of the second wavelength filter 62 is adjusted so that the third projection point P3 of the blue laser light L _B approaches (preferably substantially coincides with the first projection point P1 of the red laser light L _R ). . Further, the second wavelength filter 62 is disposed so that the light reflection surface of the first wavelength filter 61 and the light reflection surface of the second wavelength filter 62 are parallel to each other. In addition, the specific adjustment method is the same as in the aforementioned fourth step.

The optical assembly 10A of this embodiment described above and the effect obtained by the manufacturing method thereof will be described. In general, when the wavelength of the laser light is different, the refractive index of the lens is also different. Therefore, when the laser light emitted from red LD, green LD, and blue LD is collimated with one lens, chromatic aberration occurs, and it becomes difficult to align the optical axes of each laser light. On the other hand, as in the present embodiment, by disposing three collimating lenses 41 to 43 corresponding to each of the red LD 11, the green LD 12 and the blue LD 13, chromatic aberration is effectively reduced. Can be suppressed.

However, on the other hand, there are many cases where miniaturization is required for optical assemblies. When collimating lenses are arranged for each LD and the entire optical assembly is miniaturized, collimating lenses are brought close together, and resin for fixing the collimating lens (in this embodiment, an ultraviolet curable resin is used) is different from the collimating lens. It flows out to the fixed position of the lens and becomes a factor that causes the optical axis of the other collimating lens to fluctuate. Furthermore, the optical axes of the respective laser beams deviate from each other.

In view of the above problems, in the optical assembly 10A of the present embodiment, each of the collimating lenses 41 to 43 is disposed for each of the three color LDs 11 to 13. Further, these collimating lenses 41 to 43 are mounted on the main surface 30a of the base member 30 via three sub-base members 51 to 53 independent from each other. According to this configuration, it is possible to effectively prevent the resin for fixing the collimating lenses 41 to 43 from flowing out to the fixed positions of the other collimating lenses 41 to 43. Therefore, it becomes possible to suppress the fluctuation of the optical axis of the red laser light L _R , the green laser light L _G , and the blue laser light L _B emitted from the LDs 11 to 13, and to perform the optical axis adjustment more accurately. Further, the optical assembly 10A can be downsized.

Further, in the configuration described in Patent Document 3, since parallelization is performed using one lens after the three colors of laser light are combined, correction of chromatic aberration is practically impossible. Further, in the configuration described in Patent Document 4, a collimated lens is provided in each of the three LDs, but these collimated lenses are accommodated in a lens holder, and the adjustment margin of the optical axis is very limited. According to the optical assembly 10A of the present embodiment, by having the above-described configuration, it is possible to correct chromatic aberration, to sufficiently secure an adjustment margin of the optical axis, and to perform optical axis adjustment more accurately. It becomes.

In addition, in the manufacturing method of the optical assembly 10A of this embodiment, first, the red LD11 is mounted on the base member 30 (first process), and then the height of the projection point is the red LD11 The green LD (12) and the blue LD (13) are mounted on the base member 30 (second and third processes) so as to be the same as, and the first wavelength filter 61 and the second wavelength filter 62 are By using, the projection points of the green LD12 and the blue LD13 are brought close to the projection points of the red LD11 (4th and 5th processes). By this method, the optical axes of each laser light L _R , L _G and L _B emitted from each of the red LD 11, the green LD 12 and the blue LD 13 can be accurately and easily adjusted to each other. .

In addition, in the present embodiment, in the third step, the position of the projection point of the green LD 12 (the second projection point P2) and the position of the projection point of the blue LD 13 (the third projection point P3) are substantially To match, the blue LDs 13 are arranged. Thereby, a configuration in which the green LD 12 and the blue LD 13 are disposed on one side of the optical axis of the red LD 11 (see Fig. 1) can be appropriately realized. Further, in this case, in the fifth step, the second wavelength filter 62 may be disposed so as to be parallel to the first wavelength filter 61.

(2nd embodiment)

Subsequently, an optical module including the optical assembly 10A according to the first embodiment will be described. 7 is a perspective view showing the appearance of the optical module 1A according to the second embodiment. In addition, FIG. 8 is a perspective view showing the internal configuration by removing the cap 73 of the optical module 1A shown in FIG. 7. The optical module 1A of this embodiment has a form called a so-called coaxial CAN package.

In addition to the optical assembly 10A, the optical module 1A includes a stem 72, a cap 73, a condensing lens 74, and lead pins 75a to 75d. The cap 73 holds the condensing lens 74. The condensing lens 74 is above the main surface 72a of the stem 72, on the optical axis of the laser beams L _R , L _G , and L _B (refer to FIG. 1) emitted from the optical assembly 10A. Is placed in. The main surface 72a has a diameter of 5.6 mm, for example. The lead pins 75a to 75d are led out onto the main surface 72a of the stem 72. The lead pins 75a to 75c are electrically insulated from the stem 72, and the lead pin 75d is electrically connected to the stem 72.

The base member 30 of the optical assembly 10A is fixed on the main surface 72a of the stem 72, and the main surface 30a of the base member 30 extends vertically with respect to the main surface 72a of the stem 72. Has been. The optical assembly 10A is sealed by the stem 72 and the cap 73. Each of the red LD11, green LD12, and blue LD13 electrodes of the optical assembly 10A is electrically connected to lead pins 75a to 75c, respectively, via wires not shown. Further, the other electrodes of the red LD11, green LD12, and blue LD13 are electrically connected to the lead pin 75d via the stem 72.

The optical module 1A according to the present embodiment includes an optical assembly 10A. Therefore, the optical axes of each laser light L _R , L _G , and L _B (refer to Fig. 1) emitted from each of the red LD (11), green LD (12), and blue LD (13) can be precisely adjusted to each other. have. In addition, the optical module 1A can be downsized.

(3rd embodiment)

9 is a perspective view showing the appearance of an optical module 1B according to the third embodiment. In addition, FIG. 10 is a perspective view showing the internal configuration of the optical module 1B shown in FIG. 9 by removing the glass cap 83. In addition, FIG. 11(a) is a top view of the optical module 1B, and FIG. 11(b) is a side view of the optical module 1B.

The optical module 1B includes a ceramic substrate 82 and a glass cap 83 in addition to the optical assembly 10A of the first embodiment. The ceramic substrate 82 is a plate-shaped member made of ceramic (for example, AlN or SiC) having a thickness of, for example, about 1 mm, and can also serve as the base member 30 of the optical assembly 10A. The ceramic substrate 82 has a main surface 82a (corresponding to the main surface 30a of the base member 30), LDs 11 to 13 of the optical assembly 10A, collimating lenses 41 to 43, And wavelength filters 61, 62, and the like are mounted on the main surface 82a of the ceramic substrate 82. In addition, in FIGS. 9-11, illustration of the sub-base members 51-55 is abbreviate|omitted.

A plurality of electrodes 84a to 84d are provided on the main surface 82a of the ceramic substrate 82. These electrodes 84a to 84d are electrically connected to each of the LDs 11 to 13 via a wiring not shown. In one example, the main surface 82a of the ceramic substrate 82 has a rectangular shape with a long side of 5.5 mm and a short side of 3.5 mm, and 2 mm of the dimensions in the length direction is a region for arranging electrodes 84a to 84d, The optical assembly 10A is placed in the remaining 3.5 mm. The glass cap 83 is, for example, 1 mm thick, and is disposed on the main surface 82a to cover the optical assembly 10A. Further, instead of the glass cap 83, a cap made of an opaque material such as ceramic may be disposed, and the reliability of the optical module 1B can be further improved. In that case, a transparent material may be provided in a portion through which the combined light of the laser beams L _R , L _G , and L _B (refer to FIG. 1) passes.

The optical module 1B according to the present embodiment includes an optical assembly 10A. Therefore, the optical axes of each laser light L _R , L _G , and L _B (refer to Fig. 1) emitted from each of the red LD (11), green LD (12), and blue LD (13) can be precisely adjusted to each other. have. Further, the optical module 1B can be downsized.

(4th embodiment)

12 is a perspective view showing a configuration of an optical assembly 10B as a fourth embodiment. The optical assembly 10B of the present embodiment includes a reflective member 90 in addition to the configuration of the optical assembly 10A of the first embodiment. In addition, since the structure other than the reflective member 90 is the same as that of the first embodiment, detailed descriptions are omitted.

The reflective member 90 is mounted on the main surface 30a of the base member 30 and disposed on the optical axis of the composite light of the laser beams L _R , L _G , and L _B. The reflective member 90 has a light reflection surface 90a, and reflects the combined light of the laser beams L _R , L _G , and L _B. In one example, the light reflection surface 90a forms an angle of 45° with respect to the optical axis of the synthesized light and the main surface 30a, and reflects the synthesized light along the normal direction of the main surface 30a.

FIG. 13 is a diagram showing a configuration (optical module 1C) of an optical assembly 10B by adding a reflective member 90 to the optical assembly 10A of the third embodiment. In addition, in FIG. 13, illustration of the glass cap 83 is omitted. In this embodiment, when the combined light of the three-color laser beams L _R , L _G , and L _B reaches the reflective member 90 and is reflected along the normal direction of the main surface 82a of the ceramic substrate 82, The synthetic light passes through the glass cap 83 and is appropriately emitted to the outside of the optical module 1C.

14 is a perspective view showing the appearance of another optical module 1D according to the present embodiment. 15 is a perspective view showing the internal configuration of a part of the optical module 1D (ceramic package 91). This optical module 1D includes a ceramic package 91 and a condensing optical unit 92.

The ceramic package 91 accommodates the optical assembly 10B (refer to FIG. 12) of this embodiment. The ceramic package 91 is a very small package with an external size of 4.0 mm x 4.7 mm x 1.5 mm, for example, and is made of a ceramic material such as alumina. 15, the optical assembly 10B is mounted on the inner bottom surface 91a of the ceramic package 91. As shown in FIG. This inner bottom surface 91a corresponds to the main surface 30a of the base member 30 shown in FIG. 12. The combined light of the three-color laser beams L _R , L _G , and L _B generated by the optical assembly 10B is reflected by the reflective member 90 and then emitted along the normal direction of the inner bottom surface 91a. In addition, in FIG. 15, illustration of the sub-base members 51-55 is abbreviate|omitted.

The condensing optical part 92 shown in FIG. 14 has a metal holder 94 holding the condensing lens. The holder 94 has a cylindrical shape extending along the optical axis of the composite light emitted from the optical assembly 10B, and is fixed to the top plate 93 of the ceramic package 91. Further, a metal cylindrical joint 95 is fixed to the holder 94. The joint 95 has a through hole therein for passing the synthetic light. Further, a cylindrical metal sleeve 96 is fixed to the joint 95. Inside the metal sleeve 96, a ferrule (not shown) holding an optical fiber is disposed. The metal sleeve 96 functions as a receptacle, and a tip end of the optical connector is inserted into the metal sleeve 96. By providing a scanning system on the other end of the optical fiber extending from this optical connector, for example, a micro-miniature head mounted display or the like can be suitably realized. In addition, the optical module 1D may have a fixed fiber structure such as a so-called pigtail fiber instead of such a receptacle shape.

The optical assembly 10B and optical modules 1C, 1D according to the present embodiment include the configuration of the optical assembly 10A of the first embodiment. Accordingly, the optical axes of each of the laser beams L _R , L _G , and L _B emitted from each of the red LD 11, green LD 12, and blue LD 13 can be precisely adjusted to each other. Further, the optical assembly 10B and the optical modules 1C and 1D can be downsized.

(Fifth embodiment)

16 is a perspective view showing a configuration of an optical assembly 10C as a fifth embodiment. The difference between the optical assembly 10C of the present embodiment and the optical assembly 10A of the first embodiment is the direction of the green LD12. That is, the green LD 12 and the second collimated lens 42 of the present embodiment are on the opposite side of the blue LD 13 with the optical axis of the red laser light L _R extending linearly from the red LD 11 Is placed in. Therefore, the direction of the first wavelength filter 61 of the present embodiment is also different from that of the first embodiment, and both sides of the first wavelength filter 61 are at an angle of 90° to both sides of the second wavelength filter 62 Is achieved. In addition, other configurations other than the green LD 12, the second collimating lens 42, and the first wavelength filter 61 are the same as those of the first embodiment, and thus detailed descriptions thereof will be omitted.

17 is a perspective view showing the configuration of the optical module 1E of the present embodiment. The optical module 1E has a configuration in which the optical assembly 10A of the optical module 1A of the second embodiment (refer to Fig. 8) is replaced with the optical assembly 10C of the present embodiment. The base member 30 of the optical assembly 10C is fixed on the main surface 72a of the stem 72, and the main surface 30a extends vertically with respect to the main surface 72a. The optical assembly 10C is sealed by a stem 72 and a cap 73 (see Fig. 7).

The optical assembly 10C can be manufactured by the same manufacturing method as the optical assembly 10A of the first embodiment, except for the following points. That is, when manufacturing the optical assembly 10C of this embodiment, in the 3rd process of mounting the blue LD 13 and the 3rd collimating lens 43 on the base member 30, as shown in FIG. Similarly, the blue LD 13 and the third collimating lens 43 may be disposed so that the relative positional relationship between the second projection point P2 and the third projection point P3 is a relationship between the first projection point P1. Further, in the fifth step of mounting the second wavelength filter 62 on the base member 30, as shown in FIG. 19, the normal line of the light reflection surface of the first wavelength filter 61 and the second wavelength filter 62 The second wavelength filter 62 may be disposed so that the normal lines of the light reflection surfaces of) cross each other. In particular, when the optical axis of the green laser light L _{G and} the optical axis of the blue laser light L _B are parallel to each other, the normal line of the light reflection surface of the first wavelength filter 61 and the normal line of the light reflection surface of the second wavelength filter 62 are The second wavelength filters 62 may be disposed so as to form a right angle to each other.

In the optical assembly 10C of this embodiment, as in the first embodiment, each of the collimating lenses 41 to 43 is disposed for each of the three color LDs 11 to 13. Then, these collimating lenses 41 to 43 are mounted on the main surface 30a of the base member 30 via three sub-base members 51 to 53 independent from each other. With this configuration, it is possible to effectively prevent the resin for fixing the collimating lenses 41 to 43 from flowing out to the fixed position of the other collimating lenses 41 to 43. Therefore, it becomes possible to suppress the fluctuation of the optical axis of the red laser light L _R , the green laser light L _G , and the blue laser light L _B emitted from the LDs 11 to 13, and to perform the optical axis adjustment more accurately. Further, the optical assembly 10C can be downsized.

In the present embodiment, in the third step, the relative positional relationship between the projection point of the green LD 12 (the second projection point P2) and the projection point of the blue LD 13 (the third projection point P3) is red LD The blue LD 13 and the third collimating lens 43 are arranged so that the relationship between the projection point of (11) (the first projection point P1) is interposed. Thereby, a configuration in which the green LD 12 and the blue LD 13 are disposed with the optical axis of the red LD 11 interposed therebetween (see Fig. 16) can be appropriately realized.

Further, in this embodiment, since the green LD 12 and the blue LD 13 are divided to the left and right of the optical axis of the red LD 11 and arranged in a good balance, the eccentricity of the emission position of the multiplexed light with respect to the package is reduced. Can be suppressed.

In addition, in this embodiment, as shown in Fig. 18, the position of the alignment mirror 70 used in the third step is the second step (see Fig. 3) with the optical axis of the red LD 11 interposed therebetween. ) To the opposite side of the position of the alignment mirror 70. For this reason, it is necessary to prepare the two alignment mirrors 70. In addition, with regard to the coret holding the second wavelength filter 62, since the angle of the second wavelength filter 62 is different from that of the first wavelength filter 61, two types of collets having different angles are required. On the other hand, as in the first embodiment, when the green LD 12 and the blue LD 13 are disposed on one side of the optical axis of the red LD 11, one alignment mirror 70 is formed in the second and third processes. ) Can be used in common, the number of mirrors for alignment can be reduced, and alignment accuracy between the green LD12 and the blue LD13 is improved. In addition, with respect to the collets holding the first wavelength filter 61 and the second wavelength filter 62, one collet can be used in common, and manufacturing equipment can be simplified.

(6th embodiment)

20 is a perspective view showing the configuration of an optical assembly 10D as a sixth embodiment. The optical assembly 10D of the present embodiment includes a reflective member 90 in addition to the configuration of the optical assembly 10C of the fifth embodiment. In addition, since the structure other than the reflective member 90 is the same as that of the first embodiment, detailed descriptions are omitted.

The reflective member 90 is mounted on the main surface 30a of the base member 30 and disposed on the optical axis of the composite light of the laser beams L _R , L _G , and L _B. The reflective member 90 has a light reflection surface 90a, and reflects the combined light of the laser beams L _R , L _G , and L _B. In one example, the light reflection surface 90a forms an angle of 45° with respect to the optical axis of the synthesized light and the main surface 30a, and reflects the synthesized light along the normal direction of the main surface 30a.

The optical assembly 10D according to the present embodiment includes the configuration of the optical assembly 10C of the fifth embodiment. Accordingly, the optical axes of each of the laser beams L _R , L _G , and L _B emitted from each of the red LD 11, green LD 12, and blue LD 13 can be precisely adjusted to each other. Further, the optical assembly 10D can be downsized.

(7th embodiment)

21 is a perspective view showing a configuration of an optical assembly 10E as a seventh embodiment. The optical assembly 10E of this embodiment includes a first wavelength filter 63 and a second wavelength filter 64 instead of the first wavelength filter 61 and the second wavelength filter 62 of the first embodiment. do. Further, the optical assembly 10E of the present embodiment includes a reflective member 90.

The first wavelength filter 63 is a multilayer film filter formed on a glass substrate, for example, and is mounted on the main surface 30a of the base member 30 via the fourth sub-base member 54. One surface of the first wavelength filter 63 is optically coupled to the first collimating lens 41, and the other surface of the first wavelength filter 63 is coupled to the second collimating lens 42 Optically coupled. The first wavelength filter 63 reflects the red laser light L _R collimated by the first collimating lens 41 and transmits the green laser light L _G collimated by the second collimating lens 42. do. The optical axis of the red laser light L _R reflected by the first wavelength filter 63 and the optical axis of the green laser light L _G transmitted through the first wavelength filter 63 are adjusted to substantially coincide with each other.

The second wavelength filter 64 is a multilayer film filter formed on a glass substrate, for example, and is mounted on the main surface 30a of the base member 30 via the fifth sub-base member 55. One surface of the second wavelength filter 64 is optically coupled to the other surface of the first wavelength filter 63, and the other surface of the second wavelength filter 64 is a third collimated lens. It is optically combined with (43). The second wavelength filter 64 is the red laser light L _R and the green laser light L _G arriving from the first wavelength filter 63 (that is, the red laser light L _R collimated by the first collimating lens 41 ). , And the green laser light L _G collimated by the second collimating lens 42 is reflected, and the laser light L _B collimated by the third collimating lens 43 is transmitted. The optical axes of the red laser light L _R and the green laser light L _G reflected from the second wavelength filter 64 and the optical axes of the blue laser light L _B transmitted through the second wavelength filter 64 are adjusted to substantially coincide with each other. .

The reflective member 90 is mounted on the main surface 30a of the base member 30 and disposed on the optical axis of the composite light of the laser beams L _R , L _G , and L _B. The reflective member 90 has a light reflection surface 90a, and reflects the combined light of the laser beams L _R , L _G , and L _B. In one example, the light reflection surface 90a forms an angle of 45° with respect to the optical axis of the synthesized light and the main surface 30a, and reflects the synthesized light along the normal direction of the main surface 30a. Here, the reflective member 90 shown in FIGS. 12, 13, and 20 has been described on the premise that the reflective surface 90a is uniform. That is, the case where the entire surface 90a forming an angle of 45° with respect to the main surface 30a has a light reflection function has been described. As a modified example, as shown in FIG. 21, the reflection region 90b in which the reflection function is applied to only a part of the surface 90a can be used.

In the optical assembly according to the embodiment, the light of each LD (11 to 13) is converted into actual collimated light by collimating lenses (41 to 43) and then propagated. By forming the reflective area 90b to have a diameter smaller than the diameter of the collimated light, and forming the reflective area 90b so that the shape of the reflective area 90b projected onto the main surface 30a becomes circular, the combined reflected light It becomes possible to round the shape of. The visible LD of the LDs 11 to 13 generally has a so-called ridge-type structure. The output light field pattern of the ridge type LD is an ellipse. This elliptical field pattern is maintained even when passing through the collimating lens. As in this example, the field pattern of the output light of the optical assembly 10 can be converted into a circular shape by projecting the reflective region 90b on the main surface 30a into a circular shape.

In the optical assembly 10E of this embodiment, as in the first embodiment, each of the collimating lenses 41 to 43 is disposed for each of the three color LDs 11 to 13. Then, these collimating lenses 41 to 43 are mounted on the main surface 30a of the base member 30 via three sub-base members 51 to 53 independent from each other. With such a configuration, it becomes possible to suppress the fluctuation of the optical axis of the red laser light L _R , green laser light L _G , and blue laser light L _B emitted from the LDs 11 to 13, and to perform optical axis adjustment more accurately. Further, the optical assembly 10E can be downsized.

In addition, in this embodiment, unlike the first embodiment, the first wavelength filter 63 reflects the red laser light L _R and transmits the green laser light L _G. In this case, the red laser light L _R emitted from the red LD 11 corresponds to the second laser light of the present invention, and the green laser light L _G emitted from the green LD 12 is applied to the first laser light of the present invention. It is considerable. In addition, in the present embodiment, the second wavelength filter 64 reflects light from the red LD11 and the green LD12, and transmits the light from the blue LD13. That is, the second wavelength filter of the present invention transmits and reflects one of the light (red laser light L _R and green laser light L _{G in} this embodiment) arriving from the first wavelength filter 63, and the third The other of transmission and reflection may be performed on the laser light (blue laser light L _B in this embodiment).

(Eighth embodiment)

22 is a top view showing the configuration of an optical assembly 10F as an eighth embodiment. In addition, for easy understanding, illustration of the base member 30, the submounts 21 to 23, and the sub base members 51 to 55 is omitted in FIG. 22.

As shown in FIG. 22, the optical assembly 10F of this embodiment further includes the red LD14, the green LD15, and the blue LD16 in addition to the structure of 1st embodiment. Further, the optical assembly 10F further includes three λ/2 plates 24 to 26, three polarizing filters 34 to 36, and three collimating lenses 44 to 46.

The red LD 14 is the fourth LD in the present embodiment, and is a laser light (fourth laser light) included in the red wavelength region (first wavelength region) among the three wavelength regions of red, green, and blue. L _R2 is emitted. The red LD14 is mounted on a submount (not shown) different from the red LD11, and is mounted on the main surface 30a of the base member 30 via this submount. The red LD 14 emits a red laser light L _R2 with an optical axis along the main surface 30a. In this embodiment, the emission direction of the red laser light L _R2 from the red LD 14 crosses the emission direction of the red laser light L _R from the red LD 11. The wavelength of the red laser light L _R2 is 640 nm, for example, the same as the red laser light L _R of the red LD 11.

The green LD 15 is the fifth LD in the present embodiment, and emits a laser light (fifth laser light) L _G2 included in the green wavelength region (second wavelength region) of the three wavelength regions. The green LD15 is mounted on a submount (not shown) different from the green LD12, and is mounted on the main surface 30a of the base member 30 through this submount. The green LD 15 emits a green laser light L _G2 with an optical axis along the main surface 30a. In this embodiment, the emission direction of the green laser light L _G2 from the green LD 15 crosses the emission direction of the green laser light L _G from the green LD 12. The wavelength of the green laser light L _G2 is, for example, 535 nm as the green laser light L _G of the green LD 12.

The blue LD 16 is the sixth LD in the present embodiment, and emits a laser light (sixth laser light) L _B2 included in the blue wavelength region (third wavelength region) among the three wavelength regions. The blue LD16 is mounted on a submount (not shown) different from the blue LD13, and is mounted on the main surface 30a of the base member 30 via this submount. The blue LD 16 emits a blue laser light L _B2 along the optical axis along the main surface 30a. In this embodiment, the emission direction of the blue laser light L _B2 from the blue LD 16 crosses the emission direction of the blue laser light L _B from the blue LD 13. The wavelength of the blue laser light L _B2 is, for example, 440 nm as the blue laser light L _B of the blue LD 13.

Each of the collimating lenses 44 to 46 is optically coupled to respective light exit cross-sections of the red LD 14, the green LD 15, and the blue LD 16. Each of the collimating lenses 44 to 46 is a red laser light L _R2 , a green laser light L _G2 , and a blue laser light L _B2 emitted from each of the red LD (14), green LD (15), and blue LD (16). Collimate (parallelize) The collimating lenses 44 to 46 are mounted on a sub-base member (not shown), and are mounted on the main surface 30a of the base member 30 via this sub-base member.

The λ/2 plate 24 is the first λ/2 plate in this embodiment, optically coupled to the collimating lens 44, and transmits the red laser light L _R2 . At this time, the polarization plane of the red laser light L _R2 rotates by 90°. The λ/2 plate 25 is the second λ/2 plate in this embodiment, optically coupled to the collimating lens 45, and transmits the green laser light L _G2 . At this time, the polarization plane of the green laser light L _G2 rotates by 90°. The λ/2 plate 26 is the third λ/2 plate in the present embodiment, optically coupled to the collimating lens 46, and transmits the blue laser light L _B2 . At this time, the polarization plane of the blue laser light L _B2 rotates by 90°.

The polarization filters 34 to 36 are, for example, a filter having high transmittance and low reflectance for polarized light in an arbitrary plane, and low transmittance and high reflectance for polarized light in another plane perpendicular to the surface. to be.

The polarization filter 34 is a first polarization filter in the present embodiment, and one surface is optically coupled to the collimating lens 41, and the other surface is a λ/2 plate 24 It is optically combined with. The polarization filter 34 transmits one of the red laser light L _R2 and the red laser light L _R that has passed through the λ/2 plate 24 and reflects the other laser light. Polarization synthesis of light L _R and L _R2 is performed.

The polarizing filter 35 is a second polarizing filter in the present embodiment, and one surface is optically coupled to the collimating lens 42, and the other surface is a λ/2 plate 25 It is optically combined with. The polarizing filter 35 transmits one of the green laser light L _G2 and the green laser light L _G that has passed through the λ/2 plate 25 and reflects the other laser light, thereby It performs a polarization synthesis of L _G, L _G2.

The polarizing filter 36 is a third polarizing filter in the present embodiment, and one surface is optically coupled to the collimating lens 43, and the other surface is the λ/2 plate 26 and Optically coupled. The polarization filter 36 transmits one of the blue laser light L _B2 and the blue laser light L _B that has passed through the λ/2 plate 26 and reflects the other laser light. carried out the synthesis of the polarized light L _B, L _B2.

The first wavelength filter 61 transmits the synthesized light (first synthesized light) output from the polarization filter 34, that is, the synthesized light composed of red laser lights L _R and L _R2, and is output from the polarization filter 35. The synthesized light (second synthesized light), that is, the synthesized light consisting of green laser lights L _G and L _G2 is reflected. The optical axis of the synthesized light transmitted through the first wavelength filter 61 and the optical axis of the synthesized light reflected by the first wavelength filter 61 are adjusted to substantially coincide with each other.

The second wavelength filter 62 transmits the synthesized light arriving from the first wavelength filter 61, and the synthesized light (third synthesized light) output from the polarizing filter 36, that is, blue laser light L _B and L _B2 Reflects the synthetic light made of. The optical axis of the synthesized light transmitted through the second wavelength filter 62 and the optical axis of the synthesized light reflected by the second wavelength filter 62 are adjusted to substantially coincide with each other.

The optical assembly 10F of this embodiment will be described in detail. Currently, blue LDs and green LDs have not been realized as surface-emitting type, and these LDs are of a single-sided emission type. Red LD (11, 14), green LD (12, 15), and blue LD (13, 16) are single-sided light-emitting LDs, and the stacking direction of the semiconductor layers is on the main surface 30a of the base member 30 In the case of vertical, the polarization planes of laser light L _R , L _G , L _B , L _R2 , L _G2 , and L _B2 emitted from these LDs (11 to 16) are all within a plane parallel to the main plane 30a. It is included in (in the virtual surface formed by the optical axis of each color laser light). In this optical assembly 10F, after rotating the polarization plane of one of the red laser lights L _R and L _R2 (laser light L _R2 in this embodiment) by 90° by the λ/2 plate 24, these red lasers Polarization synthesis of light L _R and L _R2 is performed. Thereby, it becomes possible to output red laser light having light intensity for two LDs. The same applies to the green laser lights L _G and L _G2 and the blue laser lights L _B and L _B2 . Accordingly, according to the optical assembly 10F of the present embodiment, it is possible to appropriately combine and output the red laser light L _R2 , the green laser light L _G2 , and the blue laser light L _B2 having a greater light intensity. Such an optical assembly 10F is suitable for applications such as a projector that requires a large amount of light, for example, when the amount of light is insufficient with one LD for each color.

In addition, in the optical assembly 10F of the present embodiment, as in the first embodiment, each of the collimating lenses 41 to 46 is disposed for each of the three color LDs 11 to 16. Then, these collimating lenses 41 to 46 are mounted on the main surface 30a of the base member 30 via six sub-base members (not shown) independent from each other. With such a configuration, it becomes possible to suppress the fluctuation of the optical axis of the laser light emitted from the LDs 11 to 16, and to perform the optical axis adjustment more accurately. Further, the optical assembly 10F can be downsized.

Further, in the present embodiment, the λ/2 plates 24 to 26 are required, but since the λ/2 plates are essentially birefringent crystal plates, there is no significant increase in the size of the part. Therefore, although the number of parts increases, each λ/2 plate itself is significantly smaller than the case where individual LDs are sealed in a package as described in the prior literature. In the case of using two LDs for each color, six packages are required in the configuration described in the prior literature, but in this embodiment, each LD and λ/2 plate can be accommodated in one package, and remarkable miniaturization is possible. .

(1st modification)

23 is a top view showing a configuration of an optical assembly 10G as a modification of the eighth embodiment. In addition, for easy understanding, the illustration of the base member 30, the submounts 21 to 23, and the sub base members 51 to 55 is also omitted in FIG. 23. The optical assembly 10G of this modification has a configuration in which the red LD 14, the collimating lens 44, and the λ/2 plate 24 are removed from the configuration of the optical assembly 10F of the eighth embodiment. .

In this modified example, only red laser light is generated from a single LD (red LD 11), and for green laser light and blue laser light, respectively, two LDs (green LD (12, 15), blue LD (13, 16)). For example, in consumer-only applications such as head mounted displays, there are cases where the monochromaticity (coherency) of the laser light is not so much required. Rather, when the coherency is too strong, it becomes vulnerable to noise light, and an undesirable phenomenon such as an increase in flicker on the display may occur. It is light on the shorter wavelength side called green light and blue light rather than red light that visually blinks. Therefore, in this modification, the monochromaticity of the synthesized light is smoothed by performing polarization synthesis using two LDs for the green laser light and the blue laser light. In addition, as of the green LD and the blue LD at present, only the light output intensity of which is smaller than the light output intensity of the red LD is realized. In addition, when red laser light is synthesized with green laser light and blue laser light, it is also considered that the oscillation characteristics of red LD are impaired. Therefore, as in the present modified example, by using a plurality of LDs for green laser light and blue laser light having a relatively small light output intensity, and using a single LD for red laser light, the light intensity of three colors Balance can be properly maintained.

(2nd modification)

In the above-described eighth embodiment, the center wavelength of each of the red laser light L _R2 of the red LD 14, the green laser light L _G2 of the green LD 15, and the blue laser light L _B2 of the blue LD 16, Although it was set to be the same as the center wavelength of each of the red laser light L _R of the red LD 11, the green laser light L _G of the green LD 12, and the blue laser light L _B of the blue LD 13, coherency was reduced. In order to do this, the center wavelengths among these may be different from each other. For example, if the center wavelength of the red laser light L _R is (640+α) nm and the center wavelength of the red laser light L _R2 is (640+β) nm (however, α≠β), the red laser after synthesis The coherency of light can be reduced. Similarly, the center wavelength of the green laser light L _G is set to (530+α) nm, the center wavelength of the green laser light L _G2 is set to (530+β) nm, and the center wavelength of the blue laser light L _B is (440+) When α) nm is used and the center wavelength of the blue laser light L _B2 is (440+β) nm, the coherency of the green laser light and the blue laser light after synthesis can be reduced.

The manufacturing method of the optical assembly and the optical assembly according to the present invention are not limited to the above-described embodiments, and various modifications are possible. For example, in the first embodiment, among the three wavelength regions of red, green, and blue, the first wavelength region is the red wavelength region, the second wavelength region is the green wavelength region, and the third wavelength region is Although described as a blue wavelength region, the combination of the first to third wavelength region, the red wavelength region, the green wavelength region, and the blue wavelength region is not limited thereto, and various combinations can be applied. The same applies to the combination of the first to third laser diodes and red LD, green LD, and blue LD, and the combination of the first to third laser light, red laser light, green laser light, and blue laser light.

1A~1E: Optical module
10A-10G: Optical assembly
11, 14: red LD
12, 15: green LD
13, 16: blue LD
21: first submount
22: second submount
23: 3rd submount
24: first λ/2 plate
25: second λ/2 plate
26: 3rd λ/2 plate
30: base member
30a: if given
34: first polarization filter
35: second polarization filter
36: third polarization filter
41: first collimated lens
42: second collimated lens
43: third collimated lens
44~46: collimated lens
51: first sub-base member
52: second sub-base member
53: third sub-base member
54: fourth sub-base member
55: fifth sub-base member
61: first wavelength filter
62: second wavelength filter
70: alignment mirror
72: stem
73: cap
74: condensing lens
75a~75d: lead pin
82: ceramic substrate
83: glass cap
90: reflective member
91: ceramic package
92: condensing optical unit
93: top plate
94: holder
95: joint
96: metal sleeve
H1: virtual plane
L _B , L _B2 : Blue laser light
L _G , L _G2 : Green laser light
L _R , L _R2 : Red laser light
P1: first projection point
P2: second projection point
P3: 3rd projection point

Claims (11)

As a method of manufacturing an optical assembly that combines and outputs red, green, and blue laser light,
Based on a first laser diode emitting the first laser light so that the first laser light included in the first wavelength region among the three wavelength regions of red, green, and blue is projected onto a first projection point. A first step of mounting on the main surface of the member,
The second laser light so that the second laser light included in the second wavelength region of the three wavelength regions is projected to a second projection point whose height relative to the main surface of the base member is the same as the first projection point. A second step of mounting a second laser diode emitting light on the main surface of the base member,
The third laser light included in the third wavelength region among the three wavelength regions is projected to a third projection point having a height based on the main surface of the base member equal to the first and second projection points, A third step of mounting a third laser diode that emits a third laser light on the main surface of the base member;
Before or after the third step, a first wavelength filter that transmits the first laser light and reflects the second laser light is provided in the base member so that the second projection point approaches the first projection point. The fourth step of mounting on the main surface, and
A second wavelength filter that transmits the first and second laser beams and reflects the third laser beam is mounted on the main surface of the base member so that the third projection point approaches the first projection point. 5 process
A method of manufacturing an optical assembly comprising a.
The method of claim 1,
In the third step, a method of manufacturing an optical assembly, wherein the third laser diode is disposed so that the positions of the second and third projection points substantially coincide with each other.
The method of claim 2,
In the fifth step, a method of manufacturing an optical assembly in which the first and second wavelength filters are arranged to be parallel to each other.
The method of claim 1,
In the third step, the third laser diode is disposed so that the relative positional relationship between the second and third projection points is a relationship between the first projection points.
The method of claim 4,
In the fifth step, a method of manufacturing an optical assembly in which the first and second wavelength filters are arranged at right angles to each other.
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