Optical Module

Abstract

This optical module comprises a base part and a filter. A first main surface includes a first region and a second region. A first light, a second light, and a third light are multiplexed into a first multiplexed light in the first region. The directions of linearly polarized light of the first light and the second light included in the first multiplexed light are orthogonal. A fourth light and a fifth light are multiplexed into a second multiplexed light in the second region. The filter multiplexes the first multiplexed light and the second multiplexed light into a third multiplexed light by reflecting the first multiplexed light and transmitting the second multiplexed light, or by transmitting the first multiplexed light and reflecting the second multiplexed light. The directions of the linearly polarized light of the third light and the fourth light included in the third multiplexed light are orthogonal.

Description

Technical Field

[0001] The present disclosure relates to an optical module. This application claims priority based on Japanese Patent Application No. 2021-094293 filed on June 4, 2021, and incorporates all the descriptions described in the Japanese application.

Background Art

[0002] An optical module may include a plurality of, for example, five semiconductor light-emitting elements, and may combine and emit the respective lights emitted from the respective semiconductor light-emitting elements (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0004] The optical module according to the present disclosure includes a base portion including a first main surface, a first laser diode that emits a first light, a second laser diode that emits a second light, a third laser diode that emits a third light, a fourth laser diode that emits a fourth light, a fifth laser diode that emits a fifth light, and a filter. The first main surface includes a first region where the first laser diode, the second laser diode, and the third laser diode are provided, and a second region that is at a position different from the first region and where the fourth laser diode and the fifth laser diode are provided. The first light, the second light, and the third light are multiplexed into a first multiplexed light in the first region. The first light and the second light are of the same color. The directions of linear polarization of the first light and the second light included in the first multiplexed light are orthogonal to each other. The fourth light and the fifth light are multiplexed into a second multiplexed light in the second region. The third light and the fourth light are of the same color. The filter multiplexes the first multiplexed light and the second multiplexed light into a third multiplexed light by reflecting the first multiplexed light and transmitting the second multiplexed light, or by transmitting the first multiplexed light and reflecting the second multiplexed light. The directions of linear polarization of the third light and the fourth light included in the third multiplexed light are orthogonal to each other.

Brief Description of the Drawings

[0005]

Figure 1

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Figure 6

Embodiments for Carrying Out the Invention

[0006] [Problems to be Solved by the Present Disclosure] In an optical module, in order to increase brightness, that is, to improve optical output, a plurality of semiconductor light-emitting elements may be arranged in the optical module. Here, when arranging a plurality of semiconductor light-emitting elements in the optical module, it is desirable that the size of the optical module can be made compact. Of course, cost reduction is also required.

[0007] Therefore, one of the objects of the present disclosure is to provide an optical module that can increase the amount of light while making the size compact and can be configured at low cost.

[0008] [Effects of the Present Disclosure] According to the optical module of the present disclosure, the amount of light can be increased while making the size compact, and it can be configured at low cost.

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. The optical module according to the present disclosure includes a base including a first main surface, a first laser diode emitting a first light, a second laser diode emitting a second light, a third laser diode emitting a third light, a fourth laser diode emitting a fourth light, a fifth laser diode emitting a fifth light, and a filter. The first main surface includes a first region in which the first laser diode, the second laser diode, and the third laser diode are provided, and a second region, different from the first region, in which the fourth laser diode and the fifth laser diode are provided. The first light, the second light, and the third light are multiplexed into a first multiplexed light in the first region. The first light and the second light have the same color. The linear polarization directions of the first light and the second light included in the first multiplexed light are orthogonal. The fourth light and the fifth light are multiplexed into a second multiplexed light in the second region. The third light and the fourth light are of the same color. The filter reflects the first multiplexed light and transmits the second multiplexed light, or transmits the first multiplexed light and reflects the second multiplexed light, thereby multiplexing the first and second multiplexed lights into the third multiplexed light. The directions of the linear polarization of the third and fourth lights contained in the third multiplexed light are orthogonal. Note that "same color" means that the difference in central wavelength band is within 10 nm.

[0010] The optical module according to the present disclosure includes a first laser diode, a second laser diode, a third laser diode, a fourth laser diode, and a fifth laser diode. The first light and the second light are of the same color. The third light and the fourth light are of the same color. The filter combines the first combined light and the second combined light into third combined light by reflecting the first combined light and transmitting the second combined light, or by transmitting the first combined light and reflecting the second combined light. In the first combined light, the output of the second light is added to the output of the first light, and in the third combined light, the output of the fourth light is added to the output of the third light, thereby improving the optical output of the optical module. In the first combined light and the second combined light combined by the filter, the first light and the second light whose directions of linear polarization are orthogonal to each other are included in the first combined light, and the third light and the fourth light whose directions of linear polarization are orthogonal to each other are separately included in the first combined light and the second combined light. By adopting the method of combining waves using both polarization and wavelength in this way, it is possible to combine waves relatively easily. Therefore, it is not necessary to join triangular prism-shaped optical members like a polarization beam splitter cube and use only the difference in polarization to combine waves. Instead, it is only necessary to use a plate-shaped optical member like the above-mentioned filter, and it can be manufactured relatively inexpensively. Therefore, by adopting such a configuration, the cost of the optical module can be reduced. Also, the first laser diode, the second laser diode, and the third laser diode are mounted in the first region, and the fourth laser diode and the fifth laser diode are provided in the second region. Then, the necessity of arranging each laser diode side by side in one direction is reduced. Therefore, it becomes easy to reduce the footprint size of the optical module and make it compact. From the above, according to such an optical module, while making the size compact, it is possible to increase the amount of light and configure it at low cost.

[0011] In the above optical module, the first light and the second light, the third light and the fourth light, and the fifth light may each be visible light of any one of red, green, and blue. By doing so, it is possible to easily output the color desired by the user.

[0012] In the above optical module, the first light and the second light may be red, the third light and the fourth light may be green, and the fifth light may be blue. By doing so, it is possible to easily increase the light amounts of red and green lights.

[0013] The above optical module may include a third region arranged adjacent to the first region. The optical module may be provided in the third region and further include a mirror drive mechanism that scans the third combined light. By doing so, the mirror drive mechanism scans the third combined light by periodically swinging a mirror that reflects the third combined light. Since the optical module includes the mirror drive mechanism, the third combined light can be scanned and emitted outside the optical module. Therefore, it is possible to appropriately perform drawing by the optical module desired by the user.

[0014] In the above optical module, the base portion may include an electronic cooling module that adjusts the temperatures of the first laser diode, the second laser diode, the third laser diode, the fourth laser diode, and the fifth laser diode. The output of the light emitted from the laser diode has temperature dependence. Therefore, in order to suppress color deviation and insufficient light amount during drawing with light, it is desirable to keep the temperature as stable as possible during the operation of the optical module. By including such an electronic cooling module, it becomes easy to keep the temperatures of the respective laser diodes constant. Therefore, a more stable output can be obtained.

[0015] In the above optical module, the electronic cooling module may include a heat dissipation plate, a heat absorption plate, and a plurality of semiconductor columns. When viewed in a direction perpendicular to the first main surface, the plurality of semiconductor columns may be arranged only in the first region and the second region. By doing so, it is possible to easily adjust the temperature of each laser diode. In addition, with respect to the mirror drive mechanism, the influence of temperature change during the adjustment of each laser diode can be reduced. The swinging motion of the mirror is temperature-dependent. If the temperature of the mirror drive mechanism is not constant, the deflection angle of the mirror will change significantly. Then, the third combined light cannot be scanned appropriately. According to the above optical module, since the plurality of semiconductor columns are arranged only in the first region and the second region, they are not arranged in the third region where the mirror drive mechanism is provided. Therefore, the influence of the electronic cooling module driven during the temperature adjustment of each laser diode can be reduced. In addition, each laser diode and the mirror drive mechanism can be separated, and the distance from each laser diode to the mirror drive mechanism can be increased. Then, the influence of each laser diode that generates heat during operation can be reduced, and it becomes easy to keep the temperature of the mirror drive mechanism constant, and it is possible to suppress the change in the deflection angle of the mirror depending on the temperature. Therefore, light that is scanned more accurately can be emitted.

[0016] In the above optical module, the base portion may further include a support plate and a base plate including the first region and the second region. The electronic cooling module may be arranged between the support plate and the base plate. A first thermistor may be provided on the support plate, and a second thermistor may be provided on the base plate. By doing so, the temperature of the support plate corresponding to the ambient temperature and the temperature of the base plate that changes due to the heat generation of the laser diode can be detected, and by obtaining the difference therebetween, the temperature adjustment by the electronic cooling module can be performed accurately and efficiently.

[0017] In the above optical module, a cap having an emission window that hermetically seals the first region and the second region and transmits the third combined light may be further included. By doing so, the airtightness of the space where each laser diode is disposed can be enhanced by the cap, and it becomes easier to keep the temperature of each laser diode constant. In this case, since the cap has an emission window that transmits the third combined light, light can be output outside the optical module through this emission window.

[0018] In the above optical module, the filter may be provided in the first region or the second region. By doing so, the optical module can be miniaturized.

[0019] [Details of Embodiments of the Present Disclosure] Next, an embodiment of the optical module of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated.

[0020] (Embodiment 1) The optical module according to Embodiment 1 of the present disclosure will be described. FIG. 1 is an external perspective view showing the structure of the optical module according to Embodiment 1. FIG. 2 is an external perspective view showing a state in which the cap, which will be described later, of the optical module shown in FIG. 1 is removed. FIG. 3 is a schematic plan view of the optical module shown in FIG. 2.

[0021] Referring to FIGS. 1, 2, and 3, the optical module 10a includes an optical forming unit 11 that forms light, a base unit 12 including a first main surface 20a, and a cap 14 as a protective member that protects the optical forming unit 11. In the present embodiment, the base unit 12 includes a flat support plate 13, a flat base plate 20, and an electronic cooling module 30. The cap 14 is a lid portion welded to the support plate 13. The optical forming unit 11 is surrounded and sealed by the support plate 13 and the cap 14. The support plate 13 is rectangular when viewed from the Z-axis direction (a direction perpendicular to the first main surface), and has a shape with rounded corners. Specifically, the support plate 13 is configured such that the length in the X-axis direction is longer than the length in the Y-axis direction. The support plate 13 includes a first surface 13a perpendicular to the Z-axis direction and a second surface 13b perpendicular to the Z-axis direction. The optical forming unit 11 is disposed on the first surface 13a. The cap 14 is disposed in contact with the first surface 13a so as to cover the optical forming unit 11. The cap 14 is provided with a glass emission window 15 that transmits the light formed by the optical forming unit 11. The optical forming unit 11 is hermetically sealed by the cap 14. That is, the cap 14 is welded to the support plate 13, hermetically sealed so as to surround a first region 81, a second region 82, and a third region 83 described later, and has an emission window 15 that transmits a third combined light L8 described later. The emission window 15 is provided on the upper side of the cap 14, that is, at a position facing the first surface 13a when the cap 14 is attached to the support plate 13. A plurality of lead pins 16 are installed on the support plate 13 so as to penetrate from the second surface 13b side to the first surface 13a side of the support plate 13 and protrude on both sides of the first surface 13a side and the second surface 13b side.

[0022] The light forming unit 11 includes a first block portion 21, a second block portion 22, a third block portion 23, a fourth block portion 24, and a fifth block portion 25, each having a rectangular parallelepiped shape. The light forming unit 11 further includes a first laser diode 41 as a first semiconductor light emitting element, a second laser diode 42 as a second semiconductor light emitting element, a third laser diode 43 as a third semiconductor light emitting element, a fourth laser diode 44 as a fourth semiconductor light emitting element, and a fifth laser diode 45 as a fifth semiconductor light emitting element. The light forming unit 11 further includes a first lens 51, a second lens 52, a third lens 53, a fourth lens 54, a fifth lens 55, a first filter 61, a second filter 62, a third filter 63, a fourth filter 64, a fifth filter 65, a sixth filter 66, a wavelength plate 56 which is a half-wave plate, a wavelength plate 57 which is a half-wave plate, and a mirror drive mechanism 70. That is, in the present embodiment, the optical module 10a includes a plurality of semiconductor light emitting elements. Specifically, the optical module 10a includes five laser diodes as five semiconductor light emitting elements. The first laser diode 41 emits a first light L1 which is linearly polarized in the Y-axis direction. The second laser diode 42 emits a second light L2 which is linearly polarized in the Y-axis direction. The first light L1 and the second light L2 are of the same color and are red visible light. The wavelength range of the red light is, for example, 610 nm to 670 nm. The third laser diode 43 emits a third light L3 which is linearly polarized in the Y-axis direction. The fourth laser diode 44 emits a fourth light L4 which is linearly polarized in the X-axis direction. The third light L3 and the fourth light L4 are of the same color and are green visible light. The wavelength range of the green laser light L2 is, for example, 500 nm to 550 nm. The fifth laser diode 45 emits a fifth light L5 which is linearly polarized in the X-axis direction. The fifth light L5 is blue visible light. The wavelength range of the blue light is, for example, 410 nm to 460 nm. The first filter 61, the second filter 62, the third filter 63, the fourth filter 64, the fifth filter 65, and the sixth filter 66 are each, for example, a dielectric multilayer film filter.

[0023] The base plate 20 includes a first main surface 20a perpendicular to the Z-axis direction and a second main surface 20b opposite the first main surface 20a and perpendicular to the Z-axis direction. The first main surface 20a includes a first region 81 and a second region 82. The optical module 10a also includes a third region 83 adjacent to the first region 81 and the second region 82 when viewed from the Z-axis direction. The third region 83 is included in the first surface 32a of the heat absorption plate 32 of the electronic cooling module 30 (described later). In FIG. 3, the first region 81 is indicated by a dashed line, the second region 82 is indicated by a dashed line, and the third region 83 is indicated by a broken line. The first region 81, the second region 82, and the third region 83 do not overlap with each other and are located at different positions. The first region 81 and the second region 82 are arranged side by side in the Y-axis direction. The first region 81 and the third region 83 are arranged side by side in the X-axis direction, and the second region 82 and the third region 83 are arranged side by side in the X-axis direction. Of the sides surrounding the first region 81, the first filter 61, the second filter 62, the third filter 63, and the sixth filter 66 are provided along the side facing the second region 82.

[0024] The electronic cooling module 30 adjusts the temperatures of the first laser diode 41, the second laser diode 42, the third laser diode 43, the fourth laser diode 44, and the fifth laser diode 45. The electronic cooling module 30 is also called a TEC (Thermo-Electric Cooler), and includes a heat sink 31, a heat sink 32, and a plurality of semiconductor pillars 33. The electronic cooling module 30 is disposed between the support plate 13 and the base plate 20. The heat sink 31 is disposed on the first surface 13a of the support plate 13. The heat absorption plate 32 is disposed so as to contact the second main surface 20b of the base plate 20. That is, the base plate 20 is disposed on the first surface 32a of the heat absorption plate 32. The support plate 13 and the heat sink 31, and the base plate 20 and the heat absorption plate 32 are bonded together with a bonding material (not shown). The semiconductor pillars 33 are composed of Peltier elements and are arranged between the heat sink 31 and the heat absorption plate 32, spaced apart in the X-axis direction and the Y-axis direction, respectively. The semiconductor pillars 33 are connected to the heat sink 31 and the heat absorption plate 32. By applying electricity to the electronic cooling module 30, the temperatures of the components disposed in the region above the electronic cooling module 30 (in this embodiment, the first laser diode 41, the second laser diode 42, the third laser diode 43, the fourth laser diode 44, and the fifth laser diode 45) can be adjusted. By adjusting the current supplied to the electronic cooling module 30, it becomes easy to keep the temperature of the area above the electronic cooling module 30 constant for a long period of time, specifically, at 35°C, for example.

[0025] The optical module 10a includes a first thermistor 36 and a pedestal 37. The first thermistor 36 is disposed on the support plate 13. Specifically, the first thermistor 36 is disposed on the pedestal 37 that is disposed on the support plate 13. The pedestal 37 is disposed adjacent to the heat sink 31 when viewed from the Z-axis direction. Specifically, the pedestal 37 is disposed in a position close to the fourth laser diode 44 when viewed from the Z-axis direction. The first thermistor 36 is provided on the pedestal 37. The temperature detected by the first thermistor 36 is used for temperature adjustment by the electronic cooling module 30.

[0026] The optical module 10a also includes a second thermistor 38 and a base 39. The second thermistor 38 is disposed on the base plate 20. Specifically, the second thermistor 38 is disposed on the first main surface 20a of the base plate 20, as viewed in the Z-axis direction, at a position close to the third block portion 23, i.e., the third laser diode 43. The temperature detected by the second thermistor 38 is used for temperature adjustment by the electronic cooling module 30.

[0027] On the first region 81, a first block portion 21, a second block portion 22, and a third block portion 23 are arranged side by side at intervals in the X-axis direction. On the first block portion 21, a first laser diode 41 is arranged. On the second block portion 22, a second laser diode 42 is arranged. On the third block portion 23, a third laser diode 43 is arranged. The first laser diode 41, the second laser diode 42, and the third laser diode 43 are arranged so as to emit light in the Y-axis direction, respectively.

[0028] On the second region 82, a fourth block portion 24 and a fifth block portion 25 are arranged side by side at intervals in the Y-axis direction. On the fourth block portion 24, a fourth laser diode 44 is arranged. On the fifth block portion 25, a fifth laser diode 45 is arranged. The fourth laser diode 44 and the fifth laser diode 45 are arranged so as to emit light in the X-axis direction, respectively.

[0029] On the first region 81 of the base plate 20, a first lens 51, a second lens 52, and a third lens 53 for converting the spot size of light are arranged side by side at intervals in the X-axis direction. The first lens 51, the second lens 52, and the third lens 53 convert the spot size of the light emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43, respectively. By the first lens 51, the second lens 52, and the third lens 53, the light emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43 is converted into collimated light. Note that a wavelength plate 56 is arranged between the second laser diode 42 and the second lens 52. By this wavelength plate 56, the polarization direction of the second light L2 emitted from the second laser diode 42 can be rotated by 90 degrees and emitted.

[0030] On the second region 82 of the base plate 20, a fourth lens 54 and a fifth lens 55 for converting the spot size of light are arranged side by side at intervals in the Y-axis direction. The fourth lens 54 and the fifth lens 55 convert the spot size of the light emitted from the fourth laser diode 44 and the fifth laser diode 45, respectively. The fourth lens 54 and the fifth lens 55 convert the light emitted from the fourth laser diode 44 and the fifth laser diode 45 into collimated light. A wavelength plate 57 is arranged between the fourth laser diode 44 and the fourth lens 54. By this wavelength plate 57, the polarization direction of the fourth light L4 emitted from the fourth laser diode 44 can be rotated by 90 degrees and emitted.

[0031] On the first region 81 of the base plate 20, a first filter 61, a second filter 62, and a third filter 63 are arranged side by side at intervals in the X-axis direction. With respect to the first filter 61, the second filter 62, and the third filter 63, when viewed in the Z-axis direction, their respective reflecting surfaces are arranged so as to be inclined at 45 degrees with respect to the X-axis direction and the Y-axis direction. The first filter 61 reflects the first light L1 emitted from the first laser diode 41. The second filter 62 transmits the first light L1 reflected by the first filter 61 and reflects the second light L2 emitted from the second laser diode 42. Note that the polarization direction of the second light L2 incident on the second filter 62 is rotated by 90 degrees compared to the second light L2 immediately after being emitted from the second laser diode 42. The third filter 63 transmits the first light L1 reflected by the first filter 61 and transmitted through the second filter 62, transmits the second light L2 reflected by the second filter 62, and reflects the third light emitted from the third laser diode 43. Thus, the first filter 61, the second filter 62, and the third filter 63 selectively transmit and reflect light of a specific wavelength or polarization direction. As a result, the first filter 61, the second filter 62, and the third filter 63 multiplex the light emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43 in the first region 81. The multiplexed first multiplexed light L6 travels in the X-axis direction and reaches the sixth filter 66. The directions of linear polarization of the first light L1 and the second light L2 included in the first multiplexed light L6 are orthogonal to each other.

[0032] The fourth filter 64 and the fifth filter 65 are arranged side by side on the second region 82 of the base plate 20, spaced apart from each other in the Y-axis direction. The fourth filter 64 and the fifth filter 65 are arranged such that, when viewed in the Z-axis direction, their respective reflective surfaces are inclined 45 degrees relative to the X-axis and Y-axis directions. The fourth filter 64 reflects the fourth light L4 emitted from the fourth laser diode 44, whose polarization direction has been rotated by 90 degrees. The fifth filter 65 transmits the fourth light L4 reflected by the fourth filter 64 and reflects the fifth light L5 emitted from the fifth laser diode 45. The polarization direction of the fourth light L4 incident on the fifth filter 65 is rotated by 90 degrees compared to the fourth light L4 immediately after being emitted from the fourth laser diode 44. In this way, the fourth filter 64 and the fifth filter 65 selectively transmit and reflect light of a specific wavelength or polarization direction. As a result, the fourth filter 64 and the fifth filter 65 combine the light beams emitted from the fourth laser diode 44 and the fifth laser diode 45 in the second region 82. The combined second combined light beam L7 travels in the Y-axis direction and reaches the sixth filter 66.

[0033] A sixth filter 66 is disposed on the first region 81 of the base plate 20. The sixth filter 66 is disposed adjacent to the third filter 63 in the X-axis direction and adjacent to the fifth filter 65 in the Y-axis direction. When viewed in the Z-axis direction, the sixth filter 66 is disposed such that its reflective surface is tilted at 45 degrees with respect to the X-axis and Y-axis directions. The tilt direction of the sixth filter 66 is the same as that of the fourth filter 64 and the fifth filter 65, and is opposite to that of the first filter 61, the second filter 62, and the third filter 63, with respect to a virtual axis extending in the Y-axis direction as the axis of symmetry. The sixth filter 66 transmits the first multiplexed light L6 traveling in the X-axis direction and reflects the second multiplexed light L7 traveling in the Y-axis direction. In this way, the sixth filter 66 selectively transmits and reflects light of a specific wavelength or polarization direction. As a result, the sixth filter 66 combines the light beams emitted from the first laser diode 41, the second laser diode 42, the third laser diode 43, the fourth laser diode 44, and the fifth laser diode 45 in the first region 81. The combined third combined light beam propagates in the X-axis direction and reaches the mirror drive mechanism 70. The linear polarization directions of the third light beam L3 and the fourth light beam L4 contained in the third combined light beam L8 are orthogonal to each other.

[0034] The mirror driving mechanism 70 is configured with a MEMS (Micro Electro Mechanical System) and includes a mirror 72 capable of oscillating motion. The mirror driving mechanism 70 is supported by a triangular prism-shaped stage 71 disposed on the heat absorption plate 32. The third combined light L8 reaches the mirror 72. The mirror driving mechanism 70 periodically oscillates the mirror 72 at high speed. The mirror 72 reflects the third combined light L8 emitted from the first laser diode 41, the second laser diode 42, the third laser diode 43, the fourth laser diode 44, and the fifth laser diode 45 and combined. This causes the mirror 72 to scan the third combined light L8 emitted from the first laser diode 41, the second laser diode 42, the third laser diode 43, the fourth laser diode 44, and the fifth laser diode 45. The scanned light is emitted from the exit window 15 to the outside of the optical module 10a, thereby projecting and drawing an image.

[0035] The optical module 10a includes a first laser diode 41, a second laser diode 42, a third laser diode 43, a fourth laser diode 44, and a fifth laser diode 45. The first light L1 and the second light L2, and the third light L3 and the fourth light L4, are of the same color. That is, the difference in the central wavelength bands of the first light L1 and the second light L2 is within 10 nm. The difference in the central wavelength bands of the third light L3 and the fourth light L4 is also within 10 nm. A filter, specifically a sixth filter 66, transmits the first multiplexed light L6 and reflects the second multiplexed light L7, thereby multiplexing the first multiplexed light L6 and the second multiplexed light L7 into a third multiplexed light L8. In the first multiplexed light L6, the output of the first light L1 is added to the output of the second light L2, and in the third multiplexed light L8, the output of the third light L3 is added to the output of the fourth light L4, thereby improving the optical output of the optical module 10a. In the first multiplexed light L6 and the second multiplexed light L7 multiplexed by the sixth filter 66, the first multiplexed light L6 includes the first light L1 and the second light L2, whose linear polarization directions are orthogonal to each other, while the third light L3 and the fourth light L4, whose linear polarization directions are orthogonal to each other, are separately included in the first multiplexed light L6 and the second multiplexed light L7. This multiplexing method using both polarization and wavelength allows for relatively easy multiplexing. This eliminates the need for expensive optical components, such as a polarizing beam splitter cube, which combines triangular prism-shaped optical elements and utilizes only differences in polarization. Because only plate-shaped optical elements, like the above-mentioned filters, are required, manufacturing is relatively inexpensive. Therefore, by adopting such a configuration, the cost of the optical module 10a can be reduced. Furthermore, the first region 81 is provided with the first laser diode 41, the second laser diode 42, and the third laser diode 43, and the second region 82 is provided with the fourth laser diode 44 and the fifth laser diode 45. This eliminates the need to arrange the laser diodes in a single direction. This makes it easier to reduce the footprint of the optical module 10a and make it compact. As described above, such an optical module 10a can increase the amount of light while maintaining a compact size, and can be constructed inexpensively.

[0036] In this embodiment, the first light L1 and the second light L2, the third light L3 and the fourth light L4, and the fifth light L5 are each visible light of red, green, and blue, but the selection of the above colors is illustrative. The selection of colors only needs to be such that the first light L1 and the second light L2, and the third light L3 and the fourth light L4 are each of the same color, and the first light L1 and the second light L2, the third light L3 and the fourth light L4, and the fifth light L5 are each of different colors, that is, selected from visible light of any of red, green, and blue. Therefore, it is possible to easily output the color desired by the user.

[0037] In this embodiment, the optical module 10a includes a third region 83 disposed adjacent to the first region 81 and the second region 82. The optical module 10a includes a mirror drive mechanism 70 provided in the third region 83 for scanning the third combined light L8 combined by the sixth filter 66. Therefore, the mirror drive mechanism 70 scans the third combined light L8 by periodically swinging the mirror that reflects the third combined light L8. By including the mirror drive mechanism 70 in the optical module 10a, the third combined light L8 can be scanned and emitted outside the optical module 10a. Therefore, it is possible to appropriately perform drawing by the optical module 10a as desired by the user.

[0038] In this embodiment, the base portion 12 includes an electronic cooling module 30 that adjusts the temperatures of the first laser diode 41, the second laser diode 42, and the third laser diode 43 provided in the first region 81, and the fourth laser diode 44 and the fifth laser diode 45 provided in the second region 82. The output of the light emitted from the laser diode is temperature-dependent. Therefore, in order to suppress color deviation and insufficient light amount during drawing with light, it is desirable to keep the temperature as stable as possible during the operation of the optical module 10a. By including such an electronic cooling module 30, it becomes easy to keep the temperature of each laser diode constant. Therefore, a more stable output can be obtained.

[0039] (Embodiment 2) Next, another embodiment, embodiment 2, will be described. Fig. 4 is an external perspective view showing the optical module according to embodiment 2 with the cap removed. Fig. 5 is a schematic plan view of the optical module according to embodiment 2. The optical module according to embodiment 2 differs from embodiment 1 in that it does not include wave plates 56 and 57.

[0040] 4 and 5, the second laser diode 42 and the fourth laser diode 44 included in the optical module 10b according to the second embodiment are rotated by 90 degrees. Specifically, the second laser diode 42 is provided in the second block unit 22. Here, the second block unit 22 is rotated 90 degrees in the Y-axis direction and attached to the first region 81. Similarly, the fourth laser diode 44 is provided in the fourth block unit 24. Here, the fourth block unit 24 is rotated 90 degrees in the X-axis direction and attached to the second region 82.

[0041] By doing so, the direction of linear polarization of the first light L1 emitted from the first laser diode 41 and the direction of linear polarization of the second light L2 emitted from the second laser diode 42 are orthogonal to each other. This makes it possible to eliminate the need for the wave plate 56, thereby achieving further cost reductions. Similarly, the direction of linear polarization of the third light L3 emitted from the third laser diode 43 and the direction of linear polarization of the fourth light L4 emitted from the fourth laser diode 44 are orthogonal to each other. This makes it possible to eliminate the need for the wave plate 57, thereby achieving further cost reductions. In this case, more space is available for arranging the wave plates 56 and 57, thereby achieving further compactness.

[0042] (Embodiment 3) Next, a third embodiment, which is yet another embodiment, will be described. Fig. 6 is a schematic cross-sectional view of an optical module according to the third embodiment. The optical module according to the third embodiment differs from the first embodiment in that the configuration of the electronic cooling module is different.

[0043] Referring to FIG. 6, in the optical module 10c of Embodiment 3, when viewed in the Z-axis direction, the plurality of semiconductor pillars 33 are arranged only in the first region 81 and the second region 82. That is, in the third region 83 where the mirror drive mechanism 70 is provided, no semiconductor pillar 33 is arranged. According to such a configuration, it is possible to facilitate the temperature adjustment of each laser diode. In addition, the influence of the temperature change during the adjustment of each laser diode on the mirror drive mechanism 70 can be reduced. The swinging motion of the mirror 72 has temperature dependence. If the temperature of the mirror drive mechanism 70 is not constant, the deflection angle of the mirror 72 will change greatly. Then, the third combined light L8 cannot be scanned appropriately. According to the optical module 10c, since the plurality of semiconductor pillars 33 are arranged only in the first region 81 and the second region 82, they are not arranged in the third region 83 where the mirror drive mechanism 70 is provided. Therefore, the influence of the electronic cooling module 30 driven during the temperature adjustment of each laser diode can be reduced. In addition, each laser diode and the mirror drive mechanism 70 can be separated, and the distance from each laser diode to the mirror drive mechanism 70 can be increased. Then, the influence of each laser diode that generates heat during operation can be reduced, and it becomes easy to keep the temperature of the mirror drive mechanism 70 constant, and it is possible to suppress the change in the deflection angle of the mirror 72 depending on the temperature. Therefore, light that is scanned more accurately can be emitted.

[0044] (Other embodiments) In the above embodiment, the optical module is configured to include two red laser diodes, two green laser diodes, and one blue laser diode, but it is not limited to this. Among the red laser diode, the green laser diode, and the blue laser diode, it may be configured to include one laser diode of any color and two laser diodes of the other colors respectively. Also, the total number of laser diodes is not limited to five, and it may be configured to include two red laser diodes, two green laser diodes, and two blue laser diodes. Furthermore, laser diodes related to a combination of a plurality of colors may be used.

[0045] In the above-described embodiment, the sixth filter combines the first combined light beam and the second combined light beam into a third combined light beam by transmitting the first combined light beam and reflecting the second combined light beam. However, the present invention is not limited thereto, and the sixth filter may combine the first combined light beam and the second combined light beam into a third combined light beam by reflecting the first combined light beam and transmitting the second combined light beam.

[0046] In the above-described embodiment, regarding the electronic cooling module, when the ambient environment where the optical module is disposed is extremely low temperature, for example, heat may be released on the heat absorption plate side and heat may be absorbed on the heat dissipation plate side.

[0047] In the above-described embodiment, the base plate included in the base portion may be omitted, and the first surface of the heat absorption plate of the electronic cooling module may be applied as the first main surface. Further, the base plate and the electronic cooling module included in the base portion may be omitted, and the first surface of the support plate may be applied as the first main surface.

[0048] In the above-described embodiment, among the sides surrounding the second region, the fourth filter and the fifth filter may be provided along the side facing the first region. That is, while the configuration is such that the first region and the second region of the above-described embodiment are interchanged, a configuration in which three laser diodes are arranged in the first region and two laser diodes are arranged in the second region. At this time, the sixth filter is located in the second region.

[0049] It should be understood that the embodiments disclosed this time are illustrative in all respects and not restrictive in any way. The scope of the present invention is defined not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

Explanation of Reference Numerals

[0050] 10a, 10b, 10c Optical module 11 Optical forming unit 12 Base portion 13 Support plate Surfaces 13a, 13b, 32a 14 Cap 15 Exit window 16 Lead pin 20 Base plate 20a First main surface, 20b Second main surface 21 First block portion 22 Second block portion 23 Third block portion 24 Fourth block portion 25 Fifth block portion 30 Electronic cooling module 31 Heat sink 32 Heat absorption plate 33 Semiconductor column 36 First thermistor 37, 39 Pedestal 38 Second thermistor 41 First laser diode 42 Second laser diode 43 Third laser diode 44 Fourth laser diode 45 Fifth laser diode 51 First lens 52 Second lens 53 Third lens 54 Fourth lens 55 Fifth lens 56, 57 Waveplate 61 First filter 62 Second filter 63 Third filter 64 Fourth filter 65 Fifth filter 66 Sixth filter 70 Mirror drive mechanism 71 Stage 72 Mirror 81 First region, 82 Second region, 83 Third region L1 First light L2 Second light L3 Third light L4 Fourth light L5 Fifth light The first combined light of L6 The second combined light of L7 The third combined light of L8 X, Y, Z arrows

Claims

1. A base portion including a first main surface, A first laser diode that emits a first light, A second laser diode that emits a second light, A third laser diode that emits a third light, A fourth laser diode that emits a fourth light, A fifth laser diode that emits a fifth light, A filter, and is provided with, The first main surface, A first region where the first laser diode, the second laser diode, and the third laser diode are provided, A second region that is at a position different from the first region and where the fourth laser diode and the fifth laser diode are provided, and includes, The first light, the second light, and the third light are multiplexed into a first multiplexed light in the first region, The first light and the second light are of the same color, The directions of linearly polarized light of the first light and the second light included in the first multiplexed light are orthogonal, The fourth light and the fifth light are multiplexed into a second multiplexed light in the second region, The third light and the fourth light are of the same color, The filter multiplexes the first multiplexed light and the second multiplexed light into a third multiplexed light by reflecting the first multiplexed light and transmitting the second multiplexed light, or transmitting the first multiplexed light and reflecting the second multiplexed light, An optical module in which the directions of linearly polarized light of the third light and the fourth light included in the third multiplexed light are orthogonal.

2. The first light and the second light, The third light and the fourth light, The fifth light are respectively, Visible light of any one of red, green, and blue, the optical module according to claim 1.

3. The first light and the second light are red, The third light and the fourth light are green, The fifth light is blue, the optical module according to claim 2.

4. The optical module includes a third region disposed adjacent to the first region, The optical module further includes a mirror drive mechanism that is provided in the third region and scans the third multiplexed light, the optical module according to any one of claims 1 to 3.

5. The base portion includes an electronic cooling module that adjusts the temperatures of the first laser diode, the second laser diode, the third laser diode, the fourth laser diode, and the fifth laser diode, the optical module according to any one of claims 1 to 4.

6. The electronic cooling module, A heat sink, A heat absorber, including a plurality of semiconductor pillars; The optical module according to claim 5, wherein, when viewed in a direction perpendicular to the first main surface, the plurality of semiconductor pillars are arranged only in the first region and the second region. **Claim 7** The base portion further includes a support plate and a base plate including the first region and the second region; The electronic cooling module is disposed between the support plate and the base plate; The optical module according to claim 5 or 6, wherein a first thermistor is provided on the support plate and a second thermistor is provided on the base plate. **Claim 8** The optical module according to any one of claims 1 to 7, further including a cap that hermetically seals the first region and the second region and has an emission window that transmits the third combined light. **Claim 9** The optical module according to any one of claims 1 to 8, wherein the filter is provided in the first region or the second region.

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