JPH0722706A - Light emitting device, its viewing method, and its drive method - Google Patents

Abstract

PURPOSE:To provide light emitting device which is capable of completely new stereoscopec viewing where the efficiency for taking out output light is high, the device configuration can be miniaturized and light, and color purity and resolution of each color is high in the case of color display. CONSTITUTION:A plurality of laser devices 20 oscillating in a direction which is vertical to the main surface 1S of a substrate 1 are integrated on a substrate 1 and the dominant polarization directions of each irradiation light L of a plurality of laser devices 20 is constituted as two or more kinds of different directions as indicated by arrows (a) and (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel light emitting device in which a surface emitting laser device such as a semiconductor laser is integrated, a visual method thereof, and a driving method thereof.

[0002]

2. Description of the Related Art Generally, in a so-called projection (projection type) display in which image information is projected on a screen to be viewed, there is a problem that conversion efficiency of input power into output light is relatively low and energy efficiency is poor. Therefore, the power consumption increases and it is difficult to reduce the size. Especially in a liquid crystal transmissive projection display, the efficiency of extracting output light to the front surface is poor.

The cathode ray tube type projection display is heavy and not suitable for reduction in size and weight, requires a high voltage for driving an electron gun, and is used for high excitation used for increasing emission intensity. The phosphors (green and red) have a problem that the color purity is not good. Further, since the blue phosphor is not suitable for high excitation by electron beams and causes luminance saturation and burn-in deterioration, electron beams are often used in defocus, and the blue resolution is relatively low.

In recent years, various stereoscopic displays using so-called polarized glasses in which the polarization directions of the left and right see-through parts are different have been proposed. With such a stereoscopic display,
Since the output light is further viewed through the polarization filter, there is a problem that the extraction efficiency of the output light is low and it is difficult to obtain a sufficient light amount.

[0005]

According to the present invention, the output light extraction efficiency is good, the device configuration can be made smaller and lighter, and the color purity and resolution of each color light can be reduced when performing color display. Provided is a light-emitting device having a good and novel configuration and capable of stereoscopic viewing.

[0006]

The present invention provides a laser device 20 for emitting light in a direction substantially perpendicular to a main surface 1S of a substrate 1, as shown in a schematic diagram of an example thereof. A plurality of them are integrated on the substrate 1, and the dominant polarization directions of the emitted lights L of the plurality of laser devices 20 are configured as two or more different directions as shown by arrows a and b.

Furthermore, the present invention has the above-mentioned structure.
As shown in the schematic plan view of the example in FIG. 2, the polarization directions a and b of the emitted light of each laser device are selected to be perpendicular to each other.

Further, the present invention has the above-mentioned configuration and is similar to that shown in FIG.
A laser device 20 is arranged one-dimensionally on the substrate 1 as shown in FIGS. Further, according to the present invention, in the above structure, the laser device is two-dimensionally arranged on the substrate 1.

Further, the present invention has the above-mentioned configuration and is similar to that shown in FIG.
As shown in a schematic enlarged perspective view of an example thereof, a laser device 20 is provided with a resonator in a direction along the main surface of the substrate 1, and a reflecting mirror is provided so as to face the light emitting end surface of the resonator. 12A and 12B are provided and configured. Further, according to the present invention, in the above structure, the reflecting mirrors 12A and 12B of the laser device are formed by vapor phase growth.

Further, the present invention has the above-mentioned configuration with the configuration shown in FIG.
As shown in a schematic enlarged cross-sectional view of one example thereof, a heat sink 31 made of a material having transparency to visible light is provided on the laser device 20.

Further, according to the present invention, as shown in the schematic diagram of an example of FIG. 6, characters, images, images and the like are displayed by the light emitted from each laser device in the above-mentioned configuration. Further, according to the present invention, in each of the above-described configurations, the light emitted from the laser device 20 is configured as three primary colors of blue light L _B , red light L _R , and green light L _G.

Furthermore, the present invention is configured such that, in each of the above-mentioned configurations, a drive circuit for selecting an electrode portion of the laser device is provided on the substrate 1.

Further, according to the present invention, as shown in FIG. 7 which is an enlarged schematic plan view of an example thereof, in each of the above-mentioned configurations, the electrode portion 2 of the laser device 20 is provided on the substrate 41 separate from the substrate 1.
A drive circuit 43 for selecting the electrode portion 42 corresponding to No. 2 is provided, and the electrode portions 22 and 42 of the two substrates 1 and 41 are bonded to each other so as to face each other.

In the present invention, a plurality of laser devices for emitting light in a direction substantially perpendicular to the main surface of the substrate are integrated on the substrate as shown in FIG. The light emitting device 50 in which a plurality of laser devices have two or more polarization directions is viewed through the polarization means 51 corresponding to the polarization directions.

Furthermore, the present invention uses, in the above-mentioned visual method, the light emitting device 50 in which the two polarization directions are perpendicular to each other as indicated by arrows a and b.

Further, according to the present invention, a plurality of laser devices for emitting light in a direction substantially perpendicular to the main surface of the substrate are integrated on the substrate, and the plurality of laser devices have two or more types of polarization directions. As shown in FIG. 9 schematically showing the driving operation of the light emitting device thus manufactured, the brightness modulation is performed by modulating the current pulse width to the plurality of laser devices 20 to drive the device.

[0017]

As described above, in the present invention, the surface emitting type laser device is used, and the fact that the output light of this laser device has a specific polarization direction is used.
By arranging the laser device on the substrate so that it is oriented in the same direction, the extraction efficiency of the output light to the front surface is high due to the directivity of the laser light, and the polarization characteristics of the laser light are used as described above. It is intended to provide a light emitting device capable of stereoscopic viewing with significantly higher efficiency of using output light.

That is, the light-emitting device having such a structure is viewed through a polarization means having a visual part corresponding to the above-mentioned polarization direction, for example, so-called polarizing glasses, thereby performing stereoscopic vision utilizing a difference between left and right vision. be able to. Then, in the above-mentioned configuration, by selecting the polarization directions as two directions perpendicular to each other as shown in FIG. 2, the angle of the polarization directions of the respective parts of the polarization means corresponding to these polarization directions can be simplified, The manufacturing can be simplified.

Further, as shown in FIGS. 3A to 3E, a laser device is one-dimensionally arranged on the substrate 1, and this light is scanned by a galvanometer mirror or a polygon mirror to emit two-dimensional information. And it is possible to simplify the configuration of the wiring and the like.

On the other hand, by arranging the laser device two-dimensionally on the substrate 1 in the above-mentioned structure, two-dimensional information can be easily emitted.

Further, as shown in FIG. 4, a so-called external reflecting mirror type surface emitting laser device in which a resonator is provided in parallel with the main surface of the substrate and reflecting mirrors 12A and 12B are provided so as to face the light emitting end face thereof. Is used to facilitate control of the polarization direction, and the reflecting mirrors 12A and 12B are formed by vapor phase epitaxy.
Since the dimensional integration is simplified and the angle controllability of the reflecting mirror surface is improved in this case, the light emission direction can be accurately configured, and laser light without aberration or vignetting can be emitted.

Further, in the above-described structure, as shown in FIG. 5, a heat sink made of a material having a visible light transmitting property is provided on the laser device to improve heat dissipation and to provide a highly reliable light emitting device. Can be configured. Further, by providing an image, a character and the like as shown in FIG. 6 by the above light emitting device, it is possible to provide a stereoscopic display device which is small in size and light in weight, has a high output light extraction efficiency, and can obtain a sufficient amount of light. You can

Further, by modulating the current pulse width of the laser device of such a light emitting device, the brightness modulation can be performed easily and surely, and particularly, the accurate brightness modulation display which is not affected by the non-linearity of the laser diode element. Is possible.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the present invention, as shown in a schematic diagram of an example thereof, as shown in FIG. 1, a plurality of laser devices 20 oscillating in a direction perpendicular to a main surface 1S of a substrate 1 are integrated on the same substrate, and a plurality of these laser devices 20 are integrated. The dominant polarization direction of each emitted light L of the laser device 20 is configured to be two or more different directions as shown by arrows a and b. The laser devices may be arranged in a so-called checkered pattern in which laser devices having different polarization directions are vertically and horizontally adjacent to each other as shown in FIG. 1. As shown in FIG. 2, the laser devices are alternately arranged for each row. You may.

As such a surface emitting laser device, various configurations have been proposed as shown in FIGS. The vertical cavity laser shown in FIG.
A resonator 11 is formed in a vertical direction on the upper side, and thereafter, a groove 61 is formed from the back surface side of the substrate 1 by chemical etching or the like, and light is taken out from here in a direction perpendicular to the main surface of the substrate 1. is there. In this case, it is difficult to control the polarization direction of the laser light. In addition, since it is difficult to inject current due to the structure and the voltage between the terminals is high, there is a possibility that the energy utilization efficiency will decrease.

On the other hand, the examples of FIGS. 10B to 10D show what is called a horizontal resonator type structure in which a resonator is formed in a direction horizontal to the main surface of the substrate. FIG. 10B shows the main surface of the substrate facing the end face 11A of the resonator. A so-called external 45-degree reflecting mirror type in which the reflecting mirror 12 forming approximately 45 ° is formed. In FIG. 10C, a groove 62 forming 45 ° with respect to the main surface of the substrate is anisotropically etched by RIE (reactive ion etching) or the like. And an obliquely formed resonator end face is provided as an internal reflection mirror 12i with an internal 45-degree reflection mirror type, and FIG. 10D shows that a grating (diffraction grating) 63 is formed near a part of the active layer 3. This is a diffraction grating type laser device which extracts emitted light in a direction orthogonal to the main surface of the substrate.

Basically, these horizontal cavity type laser devices can easily align the polarization directions by the element design similarly to a normal semiconductor laser, and easily show so-called TE polarization parallel to the active layer. In addition, since it becomes easy to inject current, energy loss is extremely small in portions other than the active layer, and energy use efficiency is high. In particular, when the external 45-degree reflecting mirror type structure is adopted, a so-called edge emitting type laser structure for extracting laser light in a direction horizontal to the main surface of the substrate can be used as it is.

Further, the present applicant has previously filed Japanese Patent Application No. 4-2305.
In application No. 48, a semiconductor laser device which can be easily integrated and arranged is proposed. An example of this is shown in FIG. In this case, a horizontal resonator type having a resonator in a direction along the main surface of the substrate 1,
Reflecting mirrors 12A and 12A facing the light emitting end face of this resonator.
2B is provided. This external 45 ° reflecting mirror may be formed, for example, by selectively covering the upper part of the resonator with a resist mask or the like and performing etching or the like from an oblique direction, but the present applicant has previously filed Japanese Patent Application No. 4-230548. In the application, a structure is proposed in which these external reflecting mirrors 12A and 12B can be formed together with the resonator by vapor phase growth once by vapor phase growth.
The vapor phase growth laser device will be described below with reference to FIG.

In FIG. 4, reference numeral 1 is a substrate made of, for example, n-type GaAs of the first conductivity type, 1S is a main surface of {100} crystal faces, for example, (100) crystal faces, and 2 is, for example, n-type. Of the first conduction type clad layer made of AlGaAs, 3 is an active layer made of intrinsic GaAs, and 4 and 6 is a second conduction type made of p-type Al _x Ga _1-x As (x = 0.4). The type cladding layer 5 is, for example, n-type Al
_A first conduction type current blocking layer made of _y Ga _1-y As (y = 0.5) or the like, and extends in the cavity length direction shown by an arrow A on both sides above a portion which becomes a light emitting region of the active layer 4, for example. Formed as a pattern to form a so-called SAN (real index guide type) structure. Further, 7 is a growth blocking layer made of SiN _x or the like, 8 is made of, for example, p-type GaAs formed by re-growth, and is of a second conductivity type that forms an angle of 45 ° with the main surface 1S of the substrate 1. A crystal growth layer 9 indicates an electrode that is in ohmic contact with the crystal growth layer 7.

In this case, <0 indicated by arrow A in FIG.
10> Resonator end faces 11A and 11B so that the resonator extends in the crystal axis direction, for example, in the [010] crystal axis direction.
Is formed by vertical etching such as RIE, and the crystal growth surface forming an angle of 45 ° with respect to the principal surface 1S of the substrate 1 made of, for example, the (110) crystal surface of the {110} crystal surface facing the reflection mirror 12A and 12B. Reference numeral 10 is a highly reflective film made of a metal or dielectric multilayer film deposited on one of the reflecting mirrors 12A.

When a current is injected into this laser device, a resonator is formed between the two vertical end faces 11A and 11B to cause laser oscillation, and the light emitted once parallel to the main surface 1S of the substrate 1 is emitted. , 45 ° reflectors 12A and 12B
As a result, the light is reflected in the direction perpendicular to the substrate 1, and surface emission is realized.

As described above, the substrate 1 has such a structure.
The main plane of the crystal is {100} crystal plane, and the cavity length direction is <01
0> MOCVD in the structure selected in the crystal axis direction
GaA by (chemical vapor deposition with organometallic) method, MBE (molecular beam epitaxy) method, low pressure MOCVD method, etc.
When a compound semiconductor layer of s, AlGaAs, InP, InAlGaP, or the like is crystal-grown, if the {110} crystal plane is once grown from the edge portion on the cavity end faces 11A and 11B, the growth rate on this {110} crystal plane is Since it is relatively slow, it forms 45 ° with respect to the main surface 1S of the substrate {11
This is because the 0} crystal plane is spontaneously formed.

Therefore, as shown in FIG.
By configuring the 0} crystal planes as the reflecting mirrors 12A and 12B, the laser light emitted from the active layer 3 can be extracted in a direction substantially perpendicular to the substrate 1 as indicated by an arrow B in FIG. The light emitting laser can be constructed with good crystallinity by vapor phase growth.

In this case, since the external reflecting mirror is a crystal growth surface, the surface thereof is flat as compared with the case where the reflecting mirror is formed by conventional dry or wet etching such as RIBE (reactive ion beam etching). Property and angle controllability are remarkably excellent, and since it can be formed under the growth conditions similar to those of ordinary semiconductor lasers, it is extremely versatile and simple.

Further, in this case, as described above, for example, SAN
Since the (real index guide type) structure is adopted, the current is confined and the light is also confined in the lateral direction, which has an advantage that the threshold current can be reduced.

Further, since the semiconductor laser diode is used in the present invention as described above, the wafer itself of the two-dimensional array itself serves as a light emitting element, and it is extremely easy to reduce the size and weight, and the optical system has a simple structure. Therefore, the extraction efficiency of the output light can be further enhanced.

Further, by utilizing an external 45-degree reflecting mirror type semiconductor laser to which a horizontal cavity type is applied,
Polarization control can be performed easily and reliably.

Display can be performed by light emitted from each laser device having the above-described structure. An example of this configuration is shown in FIG. In this case, red light L _R , green light L _G ,
6 has a three-primary-color configuration in which light-emitting devices R, G, and B in which the respective laser devices that emit blue light L _B are integrated are provided.
In the above, the above-mentioned light emitting devices R, G and B are arranged on the side surface of the prism 22 through the prism 22 which transmits or reflects each color light, and the light passing through the optical lens system 23 is enlarged and projected on the screen 24. It will be configured.

Since the semiconductor laser diode has the highest electro-optical conversion efficiency among the light emitting elements, it is possible to obtain a display having much higher energy efficiency than the conventional projection display. Therefore, it is possible to reduce power consumption and reduce size and weight.

In order to emit the above-mentioned three primary color lights, the composition of the active layer in each of the above-mentioned laser device configurations is
In the case of red, (InAlGa) P or Cd (Se, T)
e), ZnSSe for blue, (Zn,
This can be achieved by using Cd) (Se, Te).

Further, the semiconductor laser diode has a sharp line spectrum with high monochromaticity in the output light, and thus it is possible to easily emit each color light by the composition of the active layer, and in some cases, the composition should be modulated. Since the emission color can be continuously changed by, it is possible to obtain an ideal color tone with extremely high purity.

When the polarization direction of each light on the screen 24 displayed in this way is simplified to form a monochromatic display, as shown in FIG. 8, the polarization direction of the emitted light from each laser is indicated by an arrow a. By arranging so as to alternately change every vertical column as shown by b and b, by using polarizing means 51 so-called polarizing glasses in which polarizing plates for transmitting light parallel to respective polarized waves are arranged on the left and right, for example. A stereoscopic display can be easily provided.

The arrangement in the polarization direction is not only arranged alternately for each column as described above, but may be arranged in a checkered pattern or alternately for each row as described above. In addition, a two-dimensional image can be displayed by scanning and irradiating the screen 24 with a one-dimensional arrangement using a galvano mirror, a polygon mirror or the like. Each example of one-dimensional arrangement is shown in FIGS.
Shown in.

In FIG. 3A, the laser devices 20 are arranged on the substrate 1 so that the polarization directions of the laser light are horizontal and vertical on the paper surface of FIG. 3 as indicated by arrows a and b.
3B shows an example in which the laser devices 20 having diagonal polarization directions orthogonal to each other as shown by arrows c and d are arranged in the horizontal direction alternately in FIG. 3B. .

Further, in FIGS. 3C and 3D, each substrate 1
Laser devices 20 having uniform polarization directions on A and 1B are arranged in a row in the lateral direction.
An example is shown in which A and 1B are provided adjacent to each other so as to extend in the horizontal direction and are arranged so that the polarization directions are different between the substrates, that is, in the vertical and horizontal directions or in two diagonal directions. Further, in FIG. 3E, the laser devices 20 having the same polarization direction are arranged in a line on the substrates 1A and 1B, and the substrates 1A and 1B are arranged so that the extension directions thereof are orthogonal to each other. An example is shown in which the polarization directions of are orthogonal to each other. In this case, it is possible to manufacture on each of the substrates 1A and 1B using exactly the same process, that is, using the same mask.

When the laser devices 20 having different polarization directions are arranged on the two substrates 1A and 1B in this way, for example, as shown in FIG. 11, the emitted lights obtained from the laser devices 20 are projected so as to overlap each other on the screen 24. , The above-mentioned polarization means 5
Visualizing this projected image using 1 enables stereoscopic viewing.

Similarly, when the laser device 20 is two-dimensionally arranged on the substrate, for example, as shown in FIG. 12, two substrates in which the laser devices having the same polarization direction are two-dimensionally arranged on the same substrate. Stereoscopic viewing is possible by arranging 1A and 1B side by side and projecting the emitted light obtained from this so as to overlap the screen 24 as shown in FIG.

On the other hand, the semiconductor laser is an element having a relatively high energy conversion efficiency, but when it is arranged on the substrate at a high density as described above, it is necessary to provide a heat sink when it is actually used. For example, when the external 45-degree reflecting mirror type semiconductor laser is used as described in FIG. 4 above, as shown in FIG. 5, the optical transparency is set so that the resonator of the laser device 20 is in contact with the upper surface of the reflecting mirror. By providing the heat sink 31 of the above, sufficient heat dissipation can be performed. As a material of the heat sink 31,
Various materials such as sapphire and diamond, which are transparent in the visible light region and have relatively high thermal conductivity, can be used.

Further, the heat sink 31 is plate-shaped,
By providing the microlens 32 on the light emitting portion, for example, the laser light can be extracted more efficiently. This microlens 32 is shown in FIGS. 13A and 13B, for example.
As shown in the manufacturing process, a resist 32r is patterned on the heat sink 31 by photolithography or the like so as to be arranged at a position corresponding to each light emission position of the laser device, and then the corners thereof are melted by heating or the like. It can be easily formed by smoothing the portion into a hemispherical shape.

Next, a method and structure for driving such a laser device will be described in detail. As shown in FIGS. 1 and 2, when the laser device 20 is two-dimensionally arranged on the substrate 1, its electrode wiring is made of, for example, an insulating material as shown in a schematic enlarged perspective view of the example in FIG. Substrate 1
A semiconductor layer 16 made of n-type GaAs or the like is formed on the above, and the laser device 20 and the reflecting mirror 12 having the above-described configuration are formed on this by vapor phase growth. R is formed in the stripe-shaped groove 17 so as to be insulated and isolated.
These grooves 17 are formed by anisotropic etching such as IE.
A metal layer of Au or the like is deposited on the semiconductor layers 16 in each column separated into two, and the electrodes 19 on the substrate side are patterned and formed in stripes. Also, for example, using the air bridge structure,
The electrode 9 on the resonator made of Au or the like is replaced with the electrode 19 on the substrate side.
It is possible to form a line address type electrode by a so-called simple matrix by patterning and forming in a stripe shape extending in a direction orthogonal to.

In such a structure, since the semiconductor laser can be driven at a low voltage, the driving section can be composed of a conventional electronic circuit, and the electrodes of the laser device can be monolithically formed on the same substrate 1. It is also possible to provide a drive circuit for selecting a part, and as shown in FIG.
An electrode 42 corresponding to the electrode portion 22 of the laser device 20 and a drive circuit 43 for selecting the electrode 42 are provided on a substrate 41 made of Si or the like, which is separate from the substrate 1 on which the laser device 20 is provided, as shown by broken lines. May be attached so that the electrode portions 22 and 42 are in contact with each other to form a so-called hybrid structure. With such a configuration, the number of electrode pads can be reduced to facilitate incorporation into the system, and further, high density and high definition can be achieved.

For example, the laser devices 20 are formed in a two-dimensional array at a pitch of 50 μm, for example, in one row (or one column).
By providing one electrode section 22 for each,
2 is, for example, 150 to 300 μm square pitch, and can be formed with a high yield by applying ordinary photolithography or the like.

As described above, by using the line address method using the simple matrix (two-layer wiring), the display can be constructed in a simple form. In this case, the resolution of the screen is determined by the number of elements, so that sharp resolution can be realized for all colors.

Next, a brightness modulation method for the light emitting device thus arranged and formed will be described below. Generally, a semiconductor laser diode is shown in FIG.
As shown in the light output characteristics, no light output can be obtained at a current below the threshold value. Therefore, when the analog signal is modulated by the current value modulation, the luminance modulation can be performed by adding the current for the threshold value and performing the control.

On the other hand, for example, it is possible to carry out luminance modulation by making the current value supplied to each laser device constant and modulating the pulse width thereof. A case where the simple matrix is driven at this time will be described with reference to FIG. In this example, the potential of the horizontal line Y ₁ to be driven in the figure is 0, the potentials of the other horizontal lines Y _{2 to} Y ₅ are E [V], and the pulse widths to the vertical lines X _{1 to} X ₅ respectively. E different from t _{1 to} t ₅
Input the pulse voltage of [V]. A reverse bias is applied to all the laser devices connected to the lateral line elements other than Y ₁ , and only the laser device on the Y ₁ line emits light. In the case of current value modulation, a voltage that gives a current value corresponding to the light output intensity is applied to the vertical lines X _{1 to} X ₅ .

As described above, by controlling the brightness by current pulse width modulation, it is possible to use the laser diode without considering the non-linearity of the current-light output.

As described above, the present invention uses the surface emitting laser, and the display which uses this does not require a cathode ray tube or a halogen lamp unlike the conventional display, and also has an optical system. A projection type display can be configured with a simple and very simple configuration.
In addition, the light emitting unit can be composed of a semiconductor wafer, which makes the size and weight significantly smaller than that of a cathode ray tube or the like. Further, the semiconductor laser diode has the highest electro-optical conversion efficiency among the light emitting elements, and can provide a display having significantly higher energy efficiency than the conventional projection display, and can reduce power consumption. .

The present invention is not limited to the above-mentioned embodiments, and various modifications and changes can be made without departing from the constitution of the present invention. The visual method and driving method are also limited to the above-mentioned examples. It goes without saying that various modes can be adopted without being carried out.

[0059]

As described above, according to the present invention, a surface emitting laser is used to provide a light emitting device capable of efficiently extracting the output light to the front surface due to the directivity of the laser light, and the polarization of the laser light. Since the wave characteristics are used, it is possible to avoid a decrease in output light utilization efficiency due to the use of a polarization filter, and to configure a stereoscopic display using polarization means.

Further, it is possible to construct a projection type display with a very simple structure without using a cathode ray tube or a halogen lamp unlike the conventional projection type display and having a simple optical system. In addition, the light emitting unit can be composed of a semiconductor wafer, which makes the size and weight significantly smaller than that of a cathode ray tube or the like. Further, the semiconductor laser diode has the highest electro-optical conversion efficiency among the light emitting elements, and can provide a display having significantly higher energy efficiency than the conventional projection display, and can reduce power consumption. .

Further, by using the semiconductor laser diode, the wafer of the two-dimensional array itself serves as a light emitting element, the size and weight can be very easily reduced, and the optical system can have a simple structure. It can be even higher.

Furthermore, by using an external 45-degree reflecting mirror type semiconductor laser to which a horizontal resonator type is applied, polarization control can be performed easily and reliably. Further, in a horizontal cavity type semiconductor laser, current injection is easier than in a vertical cavity type laser, and by using this, a light emitting device and display with low voltage driving and high energy conversion efficiency can be constructed.

Since the semiconductor laser diode has the highest electro-optical conversion efficiency among the light emitting elements, it is possible to obtain a display having much higher energy efficiency than the conventional projection display. Therefore, it is possible to reduce power consumption and reduce size and weight.

Further, the semiconductor laser diode has a sharp line spectrum with high monochromaticity in the output light, and the emission color depending on the composition of the active layer can be continuously changed as described above. It is possible to produce various color tones.

When a display is performed using such a light emitting device, the display can be configured in a simple form by using the line address method using the simple matrix (two-layer wiring) as described above. . In this case, the resolution of the screen is determined by the number of elements, so that sharp resolution can be realized for all colors.

In addition, a driving circuit such as G
It can be formed monolithically by being provided on an aAs-based semiconductor substrate, and various circuit configurations are possible, such as a drive circuit substrate being formed separately by an Si electronic circuit.

In particular, by bonding a drive circuit board composed of a Si electronic circuit to the electrode portion of the two-dimensional surface emitting laser, the number of electrode pads required for wire bonding is reduced, and it is easy to incorporate it into a system such as a display device. As a result, the manufacturing of the entire device can be simplified.

Further, by controlling the brightness by current pulse width modulation, it is possible to use the laser diode without considering the non-linearity of the current-light output.

In the case of using a surface emitting laser having a structure in which output light is extracted to the front side of the substrate, that is, the side on which vapor phase growth is performed, by using a substrate that is transparent in the visible light region and has relatively high heat conduction as a heat sink. Improve the heat dissipation of
Incorporation of microlenses and the like becomes easy.

[Brief description of drawings]

FIG. 1 is an enlarged schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic enlarged plan view of another embodiment of the present invention.

FIG. 3 is a schematic enlarged plan view of a main part of another embodiment of the present invention.

FIG. 4 is an enlarged schematic perspective view of a main part of an embodiment of the present invention.

FIG. 5 is a schematic enlarged cross-sectional view of a main part of one embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 7 is an enlarged schematic plan view of a main part of the embodiment of the present invention.

FIG. 8 is an explanatory diagram of an example of the present invention.

FIG. 9 is an explanatory diagram of a pulse modulation method.

FIG. 10 is an explanatory diagram of each example of the laser device.

FIG. 11 is a schematic configuration diagram of another embodiment of the present invention.

FIG. 12 is a schematic enlarged plan view of a main part of another embodiment of the present invention.

FIG. 13 is a manufacturing process diagram of a microlens.

FIG. 14 is an enlarged schematic perspective view of a main part of the embodiment of the present invention.

FIG. 15 is a diagram showing current-light output characteristics of a semiconductor laser.

[Explanation of symbols]

 1 Substrate 1S Main Surface 12 Reflector 20 Laser Device 22 Beam Splitter 23 Optical Lens System 24 Screen 31 Heat Sink 32 Microlens 41 Substrate 42 Electrode 43 Drive Circuit 50 Light Emitting Device 51 Polarizing Means

Claims (14)

[Claims] 1. A plurality of laser devices that emit light in a direction substantially perpendicular to the main surface of the substrate are integrated on the substrate, and the dominant polarization direction of each emitted light of the plurality of laser devices is 2. A light emitting device, characterized in that the light emitting device comprises different kinds of directions. 2. The light emitting device according to claim 1, wherein the polarization directions of the light emitted from the respective laser devices are selected so as to be perpendicular to each other. 3. The light emitting device according to claim 1 or 2, wherein the laser device is one-dimensionally arranged on the substrate. 4. The light emitting device according to claim 1 or 2, wherein the laser device is two-dimensionally arranged on the substrate. 5. The laser device has a resonator in a direction along a main surface of the substrate, and a reflecting mirror is provided so as to face a light emitting end surface of the resonator. The light emitting device according to claim 1, 2 or 3 or 4. 6. The laser according to claim 5, wherein the reflecting mirror of the laser device is formed by vapor phase growth.
The light-emitting device according to. 7. The laser device according to claim 1, further comprising a heat sink made of a material having a property of transmitting visible light, the heat sink being provided on the laser device. Light emitting device. 8. The light emitting device according to claim 1, wherein display is performed by light emitted from each of the laser devices. 9. The light emitting device according to claim 8, wherein the emitted light from each laser device is composed of three primary colors of blue light, red light and green light. 10. A drive circuit for selecting an electrode section of the laser device is provided on the substrate, wherein the drive circuit is selected from the group consisting of: 1 or 2 or 3 or 4 or 5 or 6 or 7;
Alternatively, the light emitting device according to 8 or 9. 11. A drive circuit for selecting an electrode portion corresponding to an electrode portion of the laser device is provided on a substrate separate from the substrate, and the substrate and the respective electrode portions of the separate substrate face each other. The above-mentioned claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8
Or the light-emitting device according to item 9. 12. A light-emitting device configured such that a plurality of laser devices that emit light in a direction substantially perpendicular to the main surface of the substrate are integrated on the substrate, and the plurality of laser devices have two or more types of polarization directions. A method for visualizing a light emitting device, characterized in that the device is viewed through a polarization means corresponding to the polarization direction. 13. The polarization direction is selected from two types of polarization directions perpendicular to each other.
A method for visualizing a light emitting device according to. 14. A light-emitting device configured such that a plurality of laser devices that emit light in a direction substantially perpendicular to the main surface of the substrate are integrated on the substrate, and the plurality of laser devices have two or more types of polarization directions. A method for driving a light-emitting device, characterized in that brightness modulation is performed on the device by modulating current pulse widths to the plurality of laser devices.