JPH0635019A - Light source integration type wavelength conversion element - Google Patents

Abstract

PURPOSE:To eliminate the need for applying an AR coating on the end face of an optical waveguide, to facilitate the miniaturization of the device and to facilitate a matching stage. CONSTITUTION:A semiconductor laser chip 1 generates a basic wave laser beam. An L-shaped fixing member 7 and an adhesive 8 fix and support a heat sink 3 and a KTP-SHG wavelength conversion element 6 by aligning the electric field direction of the semiconductor laser chip and the electric field direction of the Ta2O5 optical waveguide 4 in such a manner that the Ta2O5 optical waveguide 4 exists in proximity to the end face of the semiconductor laser chip 1. The basic wave laser beam is, therefore, guided to the Ta2O5 optical waveguide 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, KTiOPO.
_{4 On the} nonlinear optical crystal substrate (hereinafter referred to as KTP), Ta
_The present invention relates to a light source-integrated wavelength conversion element in which a light source is integrated with a wavelength conversion element formed by depositing a ₂ O ₅ optical waveguide.

[0002]

2. Description of the Related Art In recent years, in order to expand the range of use of laser light and optimize the use of laser light in each technical field, the second harmonic has been expanded in wavelength range by second harmonic generation (SHG). Wave laser light has come to the fore. This second
Harmonic generation converts light of frequency ω into light of frequency 2ω, thus shortening the wavelength of laser light.

For example, by using a laser beam having a shorter wavelength, the recording density can be improved in optical recording / reproducing, magneto-optical recording / reproducing, and the like.

As a means for generating such second harmonic laser light, wavelength conversion is achieved by forming a linear optical waveguide made of Ta ₂ O ₅ on a substrate of a nonlinear optical crystal element such as KTP. There is an element (hereinafter referred to as a KTP-SHG wavelength conversion element).

In the above KTP-SHG wavelength conversion element, it is desired that the fundamental wave from the semiconductor laser element be efficiently incident on the linear optical waveguide to efficiently generate the second harmonic laser light. In order to efficiently guide the fundamental wave of this semiconductor laser element to an optical waveguide such as a linear optical waveguide, the fundamental wave is focused on the end face of the optical waveguide through a lens, or when the lens is not passed through the semiconductor laser, a semiconductor laser is used. The light emitting point of the element and the end face of the optical waveguide are brought close to a distance equal to or less than the wavelength order of the fundamental wave.

[0006]

By the way, the above KTP
-In the SHG wavelength conversion element, when the above-mentioned lens is used, the fundamental wave can be made to enter the optical waveguide more easily than when a lens is not used, but since the lens is used, the number of parts is increased by this lens, The number of times of positioning is large and the loss of light is large. In addition, when an element that generates a single-mode laser beam is used as the semiconductor laser element and is used in a single-mode state, the single-mode laser beam is sensitive to return light noise. AR coating must be applied.

In the case where the lens is not used, the semiconductor laser element contained in the package is usually not used as a device because it must be used in a chip state.

Further, since the KTP-SHG wavelength conversion element has wavelength selectivity with respect to the fundamental wave from the semiconductor laser element which is the light source, it is necessary to match the optical waveguide and the semiconductor laser element. The oscillation wavelength of the laser device must be stable. That is, if the oscillation wavelength of the semiconductor laser device fluctuates, the matching will be disturbed after the above matching is performed.

The present invention has been made in view of the above circumstances, and it is possible to guide the semiconductor laser light (fundamental wave) from the semiconductor laser device to the optical waveguide of the KTP-SHG wavelength conversion device. It is an object to provide a wavelength conversion element integrated with a light source, which stabilizes the wavelength of a wave, does not make AR coating accuracy a problem in the case of a single mode fundamental wave, and facilitates matching between a semiconductor laser element and an optical waveguide. .

[0010]

A light source integrated wavelength conversion element according to the present invention comprises a substrate of a nonlinear optical crystal element, and a material having a refractive index higher than that of the nonlinear optical crystal element. A wavelength conversion element formed with an optical waveguide, a semiconductor laser element that is a light source that generates a fundamental wave incident in the optical waveguide, and the semiconductor laser element is arranged at the surface end,
The heat radiation means for radiating heat when the semiconductor laser element generates a fundamental wave, and the heat radiation means and the wavelength conversion element are fixed in a state where the optical waveguide of the wavelength conversion element is close to the end face of the semiconductor laser element. Having fixing means for supporting,
The above problem is solved by a feature of converting a fundamental wave into a laser beam having a short wavelength.

Here, the nonlinear optical crystal element has K
TiOPO ₄ (KTP) is used and Ta is used for the optical waveguide.
₂ O ₅ is used. Further, the semiconductor laser device generates a single mode fundamental wave.

In the fixing means, one surface of a member having a L-shaped cross section made of a material having a low thermal conductivity is opposed to the heat dissipation means, and the other surface orthogonal to the one surface is opposed to the waveguide element. The heat radiation means and the wavelength conversion element are fixedly supported.

Further, when the heat radiation means and the wavelength conversion element are fixedly supported by the fixing means so that the end face of the semiconductor laser element and the optical waveguide are close to each other, the electric field of the semiconductor laser element is The direction and the electric field direction of the optical waveguide are matched.

[0014]

In the wavelength conversion element integrated with a light source according to the present invention, the semiconductor laser element generates a fundamental wave, and the heat radiation means having the semiconductor laser element arranged at the surface end radiates the heat during the operation of the semiconductor laser element. The heat radiation means and the wavelength conversion element are matched by matching the electric field direction of the semiconductor laser element and the electric field direction of the optical waveguide so that the waveguide makes the fundamental wave incident and the fixing means brings the optical waveguide close to the end face of the semiconductor laser element. Support firmly.
Therefore, the fundamental wave can be guided to the optical waveguide. Further, since the optical waveguide is brought close to the end face of the semiconductor laser device, the semiconductor laser device can be oscillated in a single mode without AR coating on the end face of the semiconductor laser device. Further, since the optical waveguide can be firmly fixed to the end face of the semiconductor laser device, fluctuations in the oscillation wavelength of the semiconductor laser can be suppressed. Furthermore, in SHG, matching between the semiconductor laser device and the optical waveguide becomes easy.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a light source integrated wavelength conversion device according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of a first embodiment of a wavelength conversion element with integrated light source according to the present invention.

In FIG. 1, the first embodiment is arranged at the end of the surface of a heat sink 3 made of Cu or the like which is a heat radiating means in contact with the electrode portion 2 and generates a single mode fundamental wave laser beam. The semiconductor laser chip 1 and Ta ₂ on which the fundamental laser light from the semiconductor laser chip 1 is incident
KTP-SH consisting of O ₅ optical waveguide 4 and KTP substrate 5
A cross section which is a fixing means for fixing and supporting the heat sink 3 and the KTP-SHG wavelength conversion element 6 in a state where the G wavelength conversion element 6 and the Ta ₂ O ₅ optical waveguide 4 are close to the end face of the semiconductor laser chip 1. It has an L-shaped member 7 and an adhesive 8. Here, the refractive index of the Ta ₂ O ₅ optical waveguide 4 with respect to the fundamental laser is the KTP substrate 5
Higher than the refractive index of.

The material of the member having an L-shaped cross section (hereinafter referred to as an L-shaped fixing member) 7 which is the fixing means may be any as long as it can secure the adhesive strength, but the KTP-SHG wavelength conversion element 6 has a temperature. When a condition such as sensitivity to is added, for example, one having low thermal conductivity and high adhesive strength such as polycarbonate is required. Then, one surface of the heat sink 3 is opposed to the heat sink 3, and the other surface orthogonal to the one surface is opposed to the KTP-SHG wavelength conversion element 6, so that the heat sink 3 and the KTP-SHG wavelength conversion element 6 are fixedly supported. .

Here, the semiconductor laser chip 1 emits single mode fundamental laser light as described above. Usually, when a single mode laser light is used for the fundamental wave from the semiconductor laser device and the semiconductor laser device is used in a single mode state, the single mode laser light is sensitive to the return light noise. AR coating must be accurately applied to the tip end surface. However, as in the case of the first embodiment, the semiconductor laser chip 1 and the heat sink 3 and the KTP- with the semiconductor laser chip 1 arranged at the surface end portion are formed by the L-shaped fixing member 7 and the adhesive 8.
The SHG wavelength conversion element 6 and the fundamental laser light are efficiently transmitted to the T
a ₂ O ₅ be fixed support to be incident into the optical waveguide 4 to the semiconductor laser chip 1 side end surface of the Ta ₂ O ₅ light guide 4 may not subjected to AR coating.

This was clarified by an experiment as shown in FIG. That is, FIG. 2 shows one end surface 14a.
The relationship between the fluctuation of the oscillation wavelength and the amount of guided light is measured when the table on which the wavelength conversion element 16 composed of the optical waveguide 14 not having the AR coating and the substrate 15 is placed close to the semiconductor laser chip 11. It is a figure which shows an experiment.

The optical waveguide 14 is made of a Ta ₂ O ₅ film and has a width of 5.0 μm and a thickness of 2.0 μm. (Hereinafter, Ta ₂
O ₅ optical waveguide 14) Further, the substrate 15 is Gd
_It is composed of ₃ Ga ₅ O ₁₂ . The Ta ₂ O ₅ optical waveguide 14 (hereinafter referred to as the GGG substrate 15) is connected to the GGG substrate 15
To form on top, first, for example, CV using tantalum pentaethoxide Ta (OC ₂ H ₅ ) ₅ as a source gas
By the D method, for example, an amorphous Ta ₂ O ₅ film is formed on the GGG substrate 15 made of a GGG single crystal plate. Next, a resist pattern having a shape corresponding to the shape of the optical waveguide is formed on the Ta ₂ O ₅ film by lithography.
Using this resist pattern as a mask, the Ta ₂ O ₅ film is etched by, for example, the reactive ion etching (RIE) method. This consists of the Ta ₂ O ₅ film Ta ₂ O
_{5 The} optical waveguide 14 is formed.

In FIG. 2, an electrode portion 12 and a heat sink 1 made of, for example, Cu which is in contact with the electrode portion 12 are provided.
3, and a semiconductor laser chip 11 arranged at the end of the surface of the heat sink 13 for generating a single mode fundamental wave laser light are integrally mounted on a table 21 which can be precisely moved (hereinafter referred to as a precision moving table) 21, It is fixed. In addition, the Ta ₂ O ₅ optical waveguide 14 on which the fundamental wave laser light from the semiconductor laser chip 11 is incident and the GGG.
The wavelength conversion element 16 including the substrate 15 is also mounted and fixed on a table 22 that can be precisely moved (hereinafter referred to as a precision moving table) 22. And the precision moving table 2
2 is the direction of the arrow, that is, the amount of guided light emitted from the other end face 14b of the Ta ₂ O ₅ optical waveguide 14 facing the one end face 14a and the oscillation wavelength thereof when moved to the semiconductor laser chip 11 side. The change is measured by each measuring device (not shown) via the condenser lens 23. here,
The precision movement table 21 moves in the direction of the arrow by the movement of the precision movement table 22 after the semiconductor laser chip 11 contacts the Ta ₂ O ₅ optical waveguide 14. That is, the precision moving table 2
1 is the wavelength conversion element 14 on the precision moving table 22.
It is structured so that it can move while applying a load to.

FIG. 3 is a characteristic diagram in which the results obtained by the experiment of FIG. 2 are graphed. That is, this FIG.
Is the wavelength conversion element 1 on the semiconductor laser chip 11.
6 shows the relationship between the oscillation wavelength of the semiconductor laser chip 11 and the amount of guided light guided in the Ta ₂ O ₅ optical waveguide 14 when 6 is brought closer. In the characteristic diagram of FIG. 3, the horizontal axis represents the amount of movement of the wavelength conversion element 16 and the Ta ₂ O ₅ optical waveguide 14, and the amount of movement of the precision moving table 22 (0 μm indicates that the amount of movement is 0, 1, The moving amount becomes longer as the distance becomes 2, 3 ... 7 μm). The left vertical axis shows the guided light amount, and the right vertical axis shows the oscillation wavelength. Further, in carrying out this experiment, the semiconductor laser 11 is caused to emit light by constant current driving, and its oscillation wavelength and emission intensity (amount of guided light).
Is 790.6 nm and 22 mW in the state where the wavelength conversion element 16 does not exist in proximity (free-run state).

In FIG. 3, the broken line shows the fluctuation of the oscillation wavelength in the single mode, and the solid line shows the fluctuation of the guided light quantity. The fluctuation of the oscillation wavelength in the single mode is observed only when the movement amount of the Ta ₂ O ₅ optical waveguide 14 (hereinafter, simply referred to as the movement amount) is from 1.8 μm to 6.0 μm. This is the amount of movement of the semiconductor laser chip 11
This is because in the region of 1.8 μm or less, the single mode oscillation state is set, and the multimode oscillation state is set. The amount of movement
In the region of 1.8 μm or less, the semiconductor laser chip 11 is in the multimode oscillation state, and in this state, the movement amount of the wavelength conversion element 16 changes (0 to 1.8 μm).
Corresponding to (m), the amount of guided light in the Ta ₂ O ₅ optical waveguide 14 shown by the solid line changes periodically. This is Ta ₂ O
₅ End face 1 of the optical waveguide 14 on the semiconductor laser chip 11 side
This is because AR coating is not applied to 4a.
Normally, when the AR coating is not applied, the reflectance is about 14 to 15%, and the reflected light of about 14 to 15% returns to the inside of the semiconductor laser chip 11. At this time, due to the phase relation, a certain amount of amplitude appears in the guided light amount for each quarter wavelength of the oscillation wavelength. When the amplitude of the guided light amount is large to some extent, the semiconductor laser chip 1 is
This is when the distance between 1 and the Ta ₂ O ₅ optical waveguide 14 is large. Then, as the distance gradually decreases, the amount of returning light increases, and the amplitude of the amount of guided light gradually increases considerably. However, when the wavelength falls below 1 / 4λ, the phases of the return lights do not match (cancel each other), and the large amplitude of the guided light amount sharply decreases. In this state, the amount of movement is about 1.8 μm in FIG. 3, and the point at which the semiconductor laser chip 11 and the Ta ₂ O ₅ optical waveguide 14 start contacting each other is started.

When the precision moving table 22 is moved and the moving distance of the wavelength conversion element 16 is between 1.8 μm and 6.0 μm after the contact start point, the semiconductor laser chip 11 is in the single mode oscillation state. Next to
Furthermore, the guided light quantity in the Ta ₂ O ₅ optical waveguide 14 does not change periodically.

[0025] From FIG. 3, even if the semiconductor laser chip 11 of the single mode is not subjected to the AR coating on the end face 14a of the Ta ₂ O ₅ optical waveguide 14, the Ta ₂
If the end face 14a of the O ₅ optical waveguide 14 is moved to some extent (in the case of FIG. 3, the optical waveguide is moved from 1.8 μm to 6.0 μm) to the light emitting point of the semiconductor laser chip 11, the semiconductor laser chip 11 is brought into a single mode state. The Ta ₂ O ₅ optical waveguide 14
It can be seen that it can be guided inside. However, although the amount of guided light in the Ta ₂ O ₅ optical waveguide 14 does not change periodically, it is also found that the oscillation state of the semiconductor laser changes by several nm when the precision moving table 22 is slightly moved. .

Therefore, the Ta ₂ O ₅ optical waveguide 14 is
Is set to a position where the fundamental laser light from the semiconductor laser chip 11 is in a single mode state and the amount of guided light does not change cyclically, and the position is accurately maintained and the semiconductor laser chip 11 and It is required to fix the Ta ₂ O ₅ optical waveguide 14. For that purpose, the semiconductor laser chip 11 and the wavelength conversion element 16 may be integrated by using the fixing means as in the first embodiment, that is, the L-shaped fixing member 7 and the adhesive 8.

This integration method, that is, the fixing method of the first embodiment will be described below. First, KTP-SH
The G wavelength conversion element 6 and the L-shaped fixing member 7 are fixed by the adhesive 8. The fixed L-shaped fixing member 7 and the KTP-SHG wavelength conversion element 6 are mounted on the precision moving table 22 shown in FIG. Next, the semiconductor laser chip 1 is mounted on the precision moving table 21 shown in FIG. 2 with the electrode 2 in contact with the heat sink 3 arranged at the end of the surface, and is driven with a constant current. Then, the position of the precision moving table 22 is adjusted so that the semiconductor laser chip 1 guides in the Ta ₂ O ₅ optical waveguide 4 in a state where the semiconductor laser chip 1 oscillates a single mode fundamental laser beam. After that, the L-shaped fixing member 7 and the KTP-SHG wavelength conversion element 6 are bonded to the semiconductor laser chip 1 and the heat sink 3 with an adhesive 8. At this time, the electric field direction of the semiconductor laser chip 1 and the electric field direction of the optical waveguide 4 are made to coincide with each other and then integrated. Both the semiconductor laser chip 1 and the Ta ₂ O ₅ optical waveguide 4 are oriented in the direction perpendicular to the plane of the paper in FIG. Finally, the precision moving table 22 is removed.

With this configuration, the semiconductor laser chip 1 and the Ta ₂ O ₅ are in a state where the fundamental laser light from the semiconductor laser chip 1 is in the single mode state and the guided light amount does not change periodically. The heat sink 3 and the wavelength conversion element 6 are placed very close to the optical waveguide 4.
And can be fixedly supported by the L-shaped fixing member 7 and the adhesive 8.

FIG. 4 shows the wavelength spectrum of the semiconductor laser chip 11 in the free-run state, and FIG. 5 shows the wavelength spectrum of the guided light after the semiconductor laser chip 11 and the wavelength conversion element 16 are integrated. Further, FIG. 6 shows the wavelength spectrum of the guided light in the middle of the method of integration.
The data shown in FIGS. 4, 5 and 6 are such that the semiconductor laser is caused to emit light by constant current drive and the drive current is constant.

Therefore, in the first embodiment, by integrating the semiconductor laser chip 1 and the KTP-SHG wavelength conversion element 6, the wavelength spectrum similar to the wavelength spectrum in the free-run state shown in FIG. 4 is obtained. Can be obtained. That is, Ta ₂ O ₅ for the semiconductor laser chip 1
Since the L-shaped fixing member 7 is used to fix the optical waveguide 4 as shown in FIG. 1, the single-mode fundamental wave laser light is in an oscillation state substantially similar to the free-run state shown in FIG. .

Further, since the single mode fundamental wave laser light has an oscillation state substantially similar to the free run state, Ta
After the matching of the ₂ O ₅ optical waveguide 4 and the semiconductor laser 1 is performed, the risk that the matching is disturbed can be greatly reduced.

Next, FIG. 7 is a sectional view showing a schematic configuration of a second embodiment of the semiconductor laser integrated optical waveguide device according to the present invention. In FIG. 7, the second embodiment is a semiconductor laser chip 31 which is arranged at the end of the surface of a heat sink 33 which is a heat radiation means in contact with the electrode portion 32 and which generates a fundamental wave light of a single mode laser, and this semiconductor laser chip. and Ta ₂ O ₅ optical waveguide 34, KTP-SHG wavelength conversion device 37 consisting of KTP substrate 35 and the cladding layer 36. the fundamental wave laser beam is incident from the chip 31, the Ta ₂ O ₅
L-shaped fixing member 3 which is a fixing means for supporting the optical waveguide 34 in a state of being close to the end face of the semiconductor laser chip 31.
8 and an adhesive 39 (not shown). Here, the refractive index of the Ta ₂ O ₅ optical waveguide 34 with respect to the fundamental wave is higher than that of the KTP substrate 35. The refractive index of the clad layer 36 is lower than that of the KTP substrate 35.

KTP-S used in this second embodiment
The HG wavelength conversion element 37 is shown in FIG. K shown in FIG. 8
The TP-SHG wavelength conversion element 37 covers a KTP nonlinear optical crystal substrate 35 and a Ta ₂ O ₅ optical waveguide 34 formed on the KTP nonlinear optical crystal substrate 35 with a cladding layer 36. The clad layer 36 is formed, for example, by depositing SiO ₂ or the like to a thickness of 1 to ₂ μm, and protects the Ta ₂ O ₅ optical waveguide 34 and, due to its refractive index, Ta ₂ O ₅ optical waveguide. The power density of the fundamental wave laser light in the waveguide 34 is increased.

Tool of the KTP-SHG wavelength conversion element 37
The physical formation method is as follows. First, for example, Tan
Talpentethethoxide Ta (OC₂H_Five)_FiveThe source gas
Made of KTP single crystal plate by the CVD method used as
On the KTP substrate 35, for example, amorphous Ta₂O_Fivefilm
To form. Next, this Ta₂O_FiveLithography on the membrane
Depending on the shape of the optical waveguide
Formed by using the resist pattern as a mask.
a₂O_FiveMembrane, eg, reactive ion etching (RIE)
Etching by the method. As a result, Ta₂O_FiveA membrane
Ta consisting of₂O _FiveThe optical waveguide 34 is formed. And
Above Ta₂O_FiveThe optical waveguide 14 is covered and the cladding layer 36 is formed.
Is, for example, SiO₂Or by SiO₂And Ta
₂O_FiveComposite oxide (SiO₂)_x(Ta₂O_Five)_1-X
To a thickness of 1 to 2 μm by sputtering or a CVD method.
To form a deposit.

The material of the L-shaped fixing member 38, which is the fixing means, may be any as long as the adhesive strength can be secured as in the case of the first embodiment, but the temperature of the KTP-SHG wavelength conversion element 37 is increased. If conditions such as sensitivity are added,
For example, a material such as polycarbonate having a low heat transfer coefficient and a high adhesive strength is required. Then, one surface of the KTP-S is faced to the heat sink 33, and the other surface orthogonal to the one surface is coated with the clad layer 36.
The heat sink 33 and the KTP-SHG wavelength conversion element 37 are fixedly supported so as to face the HG wavelength conversion element 37.

The integration method of the second embodiment is almost the same as that of the first embodiment and will be omitted here.

Therefore, also in the second embodiment, the semiconductor laser chip 31 and the KTP-SHG are used.
By integrating with the wavelength conversion element 37, a wavelength spectrum similar to the wavelength spectrum in the free-run state shown in FIG. 4 can be obtained as shown in FIG. That is, since the L-shaped fixing member 38 is used to fix the Ta ₂ O ₅ optical waveguide 34 to the semiconductor laser chip 31, as shown in FIG. 7, the single mode fundamental laser light is free-running as shown in FIG. The oscillation state is almost the same as the state.

Further, according to the second embodiment, as in the first embodiment, the single mode fundamental laser light can obtain an oscillation state almost the same as the free run state.
After the Ta ₂ O ₅ optical waveguide 34 and the semiconductor laser chip 31 are matched, the risk of misaligning the matching can be greatly reduced.

The semiconductor laser integrated optical waveguide device according to the present invention is not limited to the above embodiment, and for example, as shown in FIG.
And the heat sink 43 and the KTP-SHG wavelength conversion element 4
6 and 6 may be integrated by using only the adhesive 47 as a fixing means. That is, the semiconductor laser chip 41 and the heat sink 43, which are arranged at the end of the surface of the heat sink 44 in contact with the electrode portion 42 and generate the fundamental wave laser beam of the single mode laser, and the fundamental wave laser beam from the semiconductor laser chip 41. Ta ₂ O ₅ optical waveguide 44 on which light is incident
A KTP-SHG wavelength conversion element 46 including a KTP substrate 45 and the Ta ₂ O ₅ optical waveguide 44 are placed in a state of being close to the end face of the semiconductor laser chip 41 and supported by an adhesive 47 as a fixing means. May be. However, in this case, since the KTP-SHG wavelength conversion element 46 has a small contact portion with the semiconductor laser chip 41 and the heat sink 43, the adhesive 47 should be raised and applied as shown in FIG. This secures the adhesive strength.

Further, in the first and second embodiments, the L-shaped fixing members 7 and 38 are used as the fixing means, but the shape is that the fundamental laser light is Ta ₂ O ₅ optical waveguide. And the adhesive surface on the heat sink side when there is a large amount of waveguiding
The angle between the TP-SHG wavelength conversion element and the adhesive surface is 9
Any shape may be used as long as it is 0 °. However, in this case, the condition is that the size of the device is not impaired.

In the second embodiment, KTP-S is used.
Although there is no difference in thickness between the fundamental wave entrance end side and the exit end side of the Ta ₂ O ₅ optical waveguide 34 of the HG wavelength conversion element 37,
As shown in FIG. 10, the incident end side 34a is changed to the emission end side 34b.
It may be thicker. In this case, the incidence efficiency of the fundamental wave is further improved.

Further, although the semiconductor laser chips 1 and 31 are oscillated in the single mode in the first and second embodiments, they may be oscillated in the multi mode.

[0043]

In the wavelength conversion element integrated with a light source according to the present invention, an optical waveguide is formed by depositing a material having a refractive index higher than that of the nonlinear optical crystal element on the substrate of the nonlinear optical crystal element. A wavelength conversion element, and a semiconductor laser element that is a light source that generates a fundamental wave that enters the optical waveguide,
A state in which the semiconductor laser element is arranged at the end portion of the surface and the heat dissipation means for radiating heat when the semiconductor laser element generates a fundamental wave and the optical waveguide of the wavelength conversion element are close to the end surface of the semiconductor laser element. Since it has a fixing means for fixing and supporting the heat dissipation means and the wavelength conversion element, and converts the fundamental wave into a laser beam having a short wavelength, there is no need to use a lens, and the number of parts can be reduced and positioning can be performed. When the number of times is 1, the fundamental laser light (semiconductor laser light) can be guided to the optical waveguide in the state where the light loss is small.

Further, if the end face of the optical waveguide is brought close to the end face of the semiconductor laser element to some extent, the semiconductor laser element can be oscillated in a single mode state without AR coating on the end surface of the optical waveguide. Wave laser light can be guided to the optical waveguide. Further, even when the AR coating is applied to the end face of the optical waveguide, the accuracy can be relaxed.

Further, since the semiconductor laser element is arranged at the end of the surface of the heat sink which is the heat radiation means and the heat sink and the wavelength conversion element are fixed by the L-shaped fixing member, the semiconductor laser element and the optical waveguide are in close proximity. The device can be made smaller and the device can be made smaller.

When the single mode semiconductor laser light is guided to the optical waveguide, the optical waveguide can be firmly fixed to the end face of the semiconductor laser device, so that the fluctuation of the oscillation wavelength of the semiconductor laser device is suppressed and the free run state is achieved. A stable oscillation state similar to that obtained can be obtained.

Further, matching between the semiconductor laser device and the optical waveguide becomes easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a first embodiment of a wavelength conversion element integrated with a light source according to the present invention.

FIG. 2 is a diagram showing a state of an experiment in which a wavelength conversion element is brought close to a semiconductor laser.

FIG. 3 is a characteristic diagram showing a result of the experiment shown in FIG.

FIG. 4 is a wavelength spectrum diagram in a free run state.

FIG. 5 is a wavelength spectrum diagram of guided light after completion of the integration step.

FIG. 6 is a wavelength spectrum diagram of guided light during the integration process.

FIG. 7 is a diagram showing a schematic configuration of a second embodiment.

FIG. 8 is a diagram showing the structure of a KTP-SHG wavelength conversion element used in the second embodiment.

FIG. 9 is a diagram showing a schematic configuration of another embodiment.

FIG. 10 is a diagram showing the structure of another KTP-SHG wavelength conversion element.

[Explanation of symbols]

1 ... Semiconductor laser chip 3 ... Heat sink 4 ... Ta ₂ O ₅ optical waveguide 5 ... KTP substrate 6 ... KTP-SHG wavelength conversion element 7 ... .... L-shaped fixing member 8 ... Adhesive

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H01S 3/18

Claims (1)

[Claims] 1. A wavelength conversion element in which an optical waveguide is formed by depositing a material having a refractive index higher than that of the nonlinear optical crystal element on a substrate of the nonlinear optical crystal element, and the wavelength conversion element enters into the optical waveguide. A semiconductor laser element that is a light source that generates a fundamental wave, a heat dissipation means that dissipates heat when the semiconductor laser element generates a fundamental wave, by arranging the semiconductor laser element at a surface end portion, and the wavelength conversion element Characterized in that it has fixing means for fixing and supporting the heat radiation means and the wavelength conversion element in a state where the optical waveguide of is close to the end face of the semiconductor laser element, and converts the fundamental wave into a laser beam having a shorter wavelength. A wavelength conversion element integrated with a light source.