JPH1065266A - Planar emitting type semiconductor laser element, planar emitting type semiconductor laser array, planar emitting type semiconductor laser beam scanner, planar emitting laser beam recording device and laser recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar emitting type semiconductor laser, which sets a beam diameter into one approximating type circle on a projection surface, can deepen the depth of a focal point, can lessen the restriction on the accuracy which is required to an alignment, and can stably maintain the plane of polarization, while a transverse mode is stabilized, without exerting special effects on the light output characteristics, which are provided by the planar emitting type semiconductor laser which can reduce the fluctuations of the beam diameter, which is projected on the surface of a photosensitive material by the eccentricity of a photosensitive material drum. SOLUTION: When a vertical resonator planar emitting type semiconductor laser element is constituted into such a structure that an active layer 3 is held between upper and lower semiconductor multilayer reflective films 2 and 5 on a semiconductor substrate 1, and light is emitted in the vertical direction to the substrate, at least either of the films 2 and 5 is formed so as to make the length in one direction within the surface of the substrate longer than the lengths in the other directions within the surface of the substrate, and the intensity pattern of a luminous beam is formed so as to have a directional property.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface emitting semiconductor laser device, a surface emitting semiconductor laser array, a surface emitting semiconductor laser beam scanner, a surface emitting laser beam recording apparatus, and a laser recording method.

[0002]

2. Description of the Related Art As a conventional surface emitting laser array, for example, there is an array which projects an image onto an image plane using a set of lens systems. However, when the image is projected on the photoconductor at the same magnification in the main scanning and sub-scanning directions, particularly when the image is projected on a small-diameter drum, the projection image surface is flat, while the photoconductor drum surface has a certain curvature. It has a cylindrical surface. For this reason,
The focus shifts in the sub-scanning direction in which the surface of the photosensitive drum has a curvature. In order to solve this problem, a method has been proposed in which the magnification in the sub-scanning direction is set lower than that in the main scanning direction to adjust the size of the image and reduce the focal position shift (Japanese Patent Application No. 8-8878). issue).

[0003]

However, when a normal circular surface-emitting laser is used to enlarge the image at a predetermined magnification in the main scanning direction and to enlarge or reduce it at a smaller magnification in the sub-scanning direction. In this case, the beam diameter in the sub-scanning direction projected on the photosensitive surface is smaller than the beam diameter in the main scanning direction. As a result, the depth of focus in the sub-scanning direction becomes shallower than the depth of focus in the main scanning direction, and high accuracy is required for alignment. In addition, there is a problem that the deviation of the beam diameter projected on the photoconductor becomes large due to the positional deviation due to the eccentricity of the photoconductor drum.

FIG. 1 shows a relationship between a displacement from a focal position (beam waist) and a change in beam diameter. For example, a beam narrowed to 21 μm at a focal position having a Gaussian-type intensity profile with a wavelength of 780 nm has a beam diameter of at most 24 μm even if the deviation from the focal position is 1 mm.
m. On the other hand, a beam focused to 5 μm at a focal position having a Gaussian-type intensity profile with a wavelength of 780 nm has a beam diameter of 40 μm or more when the deviation from the focal position is 1 mm, and is sensitive to positional fluctuation. is there.

On the other hand, in the case of an element structure in which an edge-emitting laser is arranged on a substrate and emitted in a direction perpendicular to the substrate using a mirror on the substrate, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-290091, When an elliptical beam is obtained and the magnification of the lens diameter in the main scanning direction and the sub-scanning direction and the element structure are selected in an appropriate relationship, the beam diameter to be projected becomes the same in the main scanning direction and the sub-scanning direction. And the depth of focus can be increased.

However, in the case of an element structure in which edge-emitting lasers are arranged on a substrate and emitted in a direction perpendicular to the substrate using a mirror on the substrate, the density for integrating the elements cannot be increased. There has been a problem that laser spots cannot be formed on the photosensitive member with high precision and high density.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a beam diameter close to a perfect circle on a projection surface, a large depth of focus, and a restriction on accuracy required for alignment. It is an object of the present invention to provide a surface-emitting type semiconductor laser capable of reducing the fluctuation of the beam diameter projected on the photoconductor surface due to the eccentricity of the photoconductor drum.

[0008]

According to the present invention, a beam generated from a surface-emitting type semiconductor laser device is provided at a predetermined magnification in one direction perpendicular to the optical axis and at a predetermined magnification in the direction perpendicular to the optical axis. When forming a spot on the photoreceptor using a projection optical system that expands or contracts at a different magnification from the other, the optical system should be such that the spot system is close to a perfect circle on the photoreceptor. A surface-emitting type laser device having a light emission pattern with a flattening rate corresponding to the magnification is formed.
For example, when a 21 μm perfect circle spot is obtained on the photoreceptor surface, if the magnification of the optical system is 7 times in the main scanning direction and 2 times in the sub-scanning direction, the light emission of the surface emitting semiconductor laser element The beam diameter is 3 μm in each direction, 1
The beam shape is adjusted according to the magnification in the main scanning direction and the sub-scanning direction, such as preparing a 0.5 μm element. In a vertical cavity surface emitting semiconductor laser,
The light emission pattern is almost a perfect circle. This is due to the fact that the laser structure is formed in a substantially symmetrical shape in the plane of the substrate.
Therefore, by making the resonator structure constituting the laser asymmetrical in the plane of the substrate, the emission pattern can be made flat. When the surface-emitting type semiconductor lasers are arrayed one-dimensionally or two-dimensionally, if the directions of the asymmetrical light-emitting patterns of the surface-emitting type semiconductor lasers are uniform, all spots are formed on the photosensitive member. Thus, the spot diameter can be made close to a perfect circle.

That is, a first feature of the present invention is that a vertical cavity surface emitting type in which an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emits light in a direction perpendicular to the substrate. In the semiconductor laser device, at least one of the upper and lower semiconductor multilayer reflective films is configured to be longer in one direction in the substrate plane than in the other direction, so that the intensity pattern of the emission beam has directionality. It has been configured.

A second feature of the present invention is that an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate,
In a vertical cavity surface emitting semiconductor laser device that emits light in a direction perpendicular to the substrate, the active layer is configured to be longer in one direction in the substrate surface than in the other direction, and the intensity of the emission beam is increased. That is, the pattern is configured to have directionality.

A third feature of the present invention is that an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate,
In a vertical cavity surface emitting semiconductor laser device that emits light in a direction perpendicular to the substrate, a current confinement region provided outside or between the upper and lower semiconductor multilayer reflective films or between these and the active layer may be: The configuration is such that one direction in the substrate plane is configured to be longer than the other direction, and the intensity pattern of the emission beam is configured to have directionality.

Preferably, the current confinement region is AlAs
It is characterized by being composed of an oxide.

A fourth feature of the present invention is that an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate,
In a vertical cavity surface emitting semiconductor laser device that emits light in a direction perpendicular to a substrate, at least one of the upper and lower semiconductor multilayer reflective films is coated with a material having a lower refractive index than its effective refractive index. Is to be.

A fifth feature of the present invention is that an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate,
In a vertical cavity surface emitting semiconductor laser device that emits light in a direction perpendicular to the substrate, a plurality of vertical cavity surface emitting semiconductor laser devices are arranged in an array on the substrate surface. Are configured to have directionality.

According to a sixth aspect of the present invention, a surface emitting semiconductor laser scanner is characterized in that a laser light source and a first light source for expanding a beam emitted from the laser light source at a first magnification in a main scanning direction.
Lens system, a second lens system for enlarging or reducing at a second magnification in the sub-scanning direction, and a drive surface for driving and scanning a beam from the laser light source, and a scanning surface via the first and second lens systems. A driving scanning system for guiding the laser beam upward, and the intensity pattern of the emitted light beam of the element is adjusted so that the laser light source is adjusted to the first and second magnifications so that the beam becomes substantially a perfect circle on the scanning surface. A vertical cavity surface emitting semiconductor laser device having a plurality of vertical cavity surface emitting semiconductor laser elements is arranged in an array on a substrate surface.

The seventh recording apparatus according to the present invention is characterized in that a laser light source, a first lens system for expanding a beam emitted from the laser light source at a first magnification in a main scanning direction, and a sub-scanning direction. A second lens system for enlarging or reducing at a second magnification, a photoreceptor for forming an electrostatic latent image by sensitizing with a beam, and driving and scanning a beam from the laser light source to form the first and second lenses; A drive scanning system that guides the image onto the photoreceptor surface via a system, and a recording unit that performs image recording based on the electrostatic latent image, wherein the laser light source is adjusted to the first and second magnifications, Vertical-cavity surface-emitting type semiconductor laser devices, which are configured so that the intensity pattern of the light-emitting beam of the device has directivity so that the beam becomes almost a perfect circle on the scanning surface, are arrayed in the substrate plane. Surface emitting semiconductor lasers In that it is constituted by a laser device.

An eighth feature of the present invention is that a laser beam emitted from a laser light source is transmitted through a first lens system and a second lens system in a first scanning direction and a second scanning direction, respectively. The step of forming an electrostatic latent image on the photoreceptor surface, and a recording step of performing image recording based on the electrostatic latent image,
A vertical cavity configured such that the laser light source is directed to the intensity pattern of the light-emitting beam of the element so that the beam becomes substantially a perfect circle on the scanning surface in accordance with the first and second magnifications. A surface emitting semiconductor laser device in which a plurality of surface emitting semiconductor laser elements are arranged in an array in a substrate surface.

According to the present invention, the beam emitted from the surface-emitting type semiconductor laser is irradiated at a predetermined magnification in one direction perpendicular to the optical axis and in the other direction perpendicular to the optical axis. When using a projection optical system that expands or contracts at different magnifications, the beam diameter in each direction is adjusted in accordance with these magnifications so as to be substantially a perfect circle on the photoconductor. For this reason, the depth of focus can be increased, and the restriction on the accuracy required for alignment can be reduced.
Therefore, even when the photosensitive drum is eccentric, the fluctuation of the beam diameter can be suppressed.

Therefore, when recording is performed using this surface-emitting type semiconductor laser device, highly accurate and highly reliable recording can be performed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIGS. 2A and 2B are a top view and a sectional view, respectively, of a surface emitting semiconductor laser device according to a first embodiment of the present invention.

This surface-emitting type semiconductor laser device is composed of an n-type Al-GaAs substrate formed on an n-type gallium arsenide (GaAs) substrate 1.
_0.9 Ga _0.1 As / Al _0.3 Ga _0.7 As Lower semiconductor multilayer reflective film 2 (multiple diffraction Bragg reflector (DBR), undoped Al _0.11 Ga _0.89 quantum well layer formed thereon and undoped Al _0.3 Ga _0.7 As A quantum well active layer 3 composed of a barrier layer, and formed by oxidation of AlAs;
A current confinement layer 4 having an opening in the center, and p-type Al _0.9 Ga
_0.1 As / Al _0.3 Ga _0.7 As upper semiconductor multilayer reflective film 5
, A p-type GaAs contact layer (not shown), and a p-type electrode 6 are sequentially laminated, and are etched away to a depth where the side surfaces of the current confinement layer 4 are exposed, excluding the light-emitting region and the periphery thereof. The light control region 7 is formed. And here, on the lowermost layer of the upper semiconductor multilayer reflection film 5,
Except for the central opening, a current constriction layer is formed by oxidizing the AlAs layer, and a region other than this opening has a structure in which no current flows in the deposition direction. In addition, between the quantum well active layer 3 and the current confinement layer 4, Al _{0.11 is} used to protect the quantum well active layer 3 from intrusion of impurities.
An isolation layer s made of Ga _0.89 As is interposed.

A second opening is formed at the center of the p-type electrode 6 so as to include the upper portion of the opening of the current confinement layer. From this opening, a second upper multilayer reflecting film is formed on the upper semiconductor multilayer reflecting film 5. 8 are formed so as to project in a columnar shape.

Further, around the light control region, a first layer made of silicon nitride is formed at least halfway through the upper multilayer reflective film 5.
The upper layer is covered with a second insulating film 10 made of silicon oxide up to the height of the second upper multilayer reflective film 8.
Is formed so that the refractive index is different between the columnar portion of the second upper multilayer reflective film 8 and the periphery thereof, and as shown in FIGS. 3 and 4, the second upper multilayer reflective film 8 is formed. , An elliptical beam profile flattened in the lateral direction is formed. Here, the second upper multilayer reflective film 8 has a rectangular shape of 5: 1, FIG. 3 shows a contour line of the beam intensity profile at this time, and FIG. 4 shows the contour line three-dimensionally. .

An n-side electrode (not shown) made of Au-Ge / Au is formed on the back surface of the substrate.

Here, the n-type lower semiconductor multilayer reflective film 2
-Type Al _0.9 Ga _0.1 As layer and n-type Al _0.7 Ga _0.3 AsGa
An As layer is formed by laminating about 40.5 cycles of an As layer with a thickness of λ / (4nr) (λ: oscillation wavelength, _nr : refractive index), and the concentration of silicon as an n-type impurity is 2 × It is 10 ¹⁸ cm ^-3 . In addition, the quantum well active layer 4
Is a combination of an undoped Al _0.11 Ga _0.89 quantum well layer (thickness 8 nm × 3) and an undoped Al _0.3 Ga _0.7 As barrier layer (thickness 5 nm × 4). Further, the upper semiconductor multilayer reflective film 7 is composed of a p-type Al _0.9 Ga _0.1 As layer and a p-type Al _0.7 Ga _0.3 AsGaAs layer each having a thickness of λ / (4n _r ) (λ: oscillation wavelength, n _r : refractive index). Are formed by alternately laminating 30 cycles, and the concentration of carbon as a p-type impurity is 3 × 10 ¹⁸ cm ⁻³ .
Finally, the second upper semiconductor multilayer reflective film 8 is undoped. The type of the dopant is not limited to those used here, and it is also possible to use selenium for the n-type and zinc or magnesium for the p-type.

In the above embodiment, the current constriction is performed by forming the oxide film from the side surface of the columnar region by selectively oxidizing the AlAs layer. However, the void may be formed by selective etching. The shape of the opening surrounded by the current confinement layer may be a perfect circle or a square symmetric structure, or may be an asymmetric structure such as an ellipse or a rectangle.

Here, it was designed to extract a laser beam having an oscillation wavelength λ: 780 nm.

According to this configuration, the prismatic light control region 7
Is narrowed from the two sets of symmetry plane directions of the openings of the current confinement layer 4 and the light is confined. In addition, since a difference in the refractive index occurs between the second upper semiconductor multilayer reflective film 8 and the second insulating layer 10 around the second upper semiconductor multilayer reflective film 8, an elliptical beam profile that is flattened on the symmetrical surface side where the refractive index difference is smaller. Becomes This also gives
The plane of polarization of the emitted light is stabilized in this direction.

Next, the manufacturing process of this surface emitting semiconductor laser device will be described.

First, as shown in FIG. 2, n-type gallium arsenide (GaAs) is formed by metal organic chemical vapor deposition (MOCVD).
s) On the (100) substrate 1, n-type Al _0.9 Ga _0.1 As /
Al _0.7 Ga _0.3 As lower semiconductor multilayer reflective film 3, undoped Al _0.11 Ga _0.89 quantum well layer and undoped A
Quantum well active layer 3 comprising l _0.3 Ga _0.7 As barrier layer
And a separation layer S composed of an Al _0.11 Ga _0.89 As layer,
s layer and p-type _{Al 0.9 Ga 0.1 As / Al 0.7} Ga 0.3 As
An upper semiconductor multilayer reflective film 5 and a p-type GaAs contact layer (not shown) are sequentially laminated. Then, the substrate is taken out of the growth chamber, an insulating film such as a silicon oxide film is formed, and the semiconductor layer is etched and removed by photolithography using reactive ion etching using SiCl ₄ gas to a depth at which the AlAs layer is exposed. Thus, the light control region 7 made of a prismatic semiconductor pillar is formed.

Subsequently, the substrate is heated to 400 ° C. in a quartz tube filled with high-temperature water vapor and subjected to a heat treatment for about 10 minutes, whereby the exposed AlAs layer is gradually oxidized from the outer cross section. A film is formed, and a region which is finally left unoxidized has a rectangular shape. Here, instead of the oxidation by the heat treatment, a sulfuric acid hydrogen peroxide solution (H
₂ SO ₄ : H ₂ O ₂ : H ₂ O = 1: 1: 5) for about 30 seconds, whereby the AlAs layer is selectively removed from the outer cross section by so-called side etching. You.

Thereafter, a first insulating layer 9 made of a silicon nitride layer is formed while leaving a resist mask on the surface.
The first insulating layer on the upper surface of the columnar region is removed by lift-off, and silicon oxide is removed by selective etching.

Thereafter, an annular p-side electrode 6 is formed by using a vapor deposition method and a photolithography technique so as to cover around the light control region 7. The second upper semiconductor multilayer reflective film 8 is formed while the resist used for patterning the central p-side electrode is left, and the film other than the opening is removed together with the resist by lift-off to form a columnar region.

Finally, a second insulating layer 10 made of a silicon oxide layer is formed so as to cover the entire surface, and an n-side electrode is formed on the entire back surface of the substrate, and according to the present invention shown in FIG. The surface emitting semiconductor laser device of the first embodiment is completed.

In the above embodiment, each semiconductor layer is formed by metal organic chemical vapor deposition. However, the present invention is not limited to this. For example, molecular beam epitaxy (MBE) may be used.

The insulating film used as a mask for forming the semiconductor pillar is not limited to the silicon oxide film, but may be another material such as a silicon nitride film.

Further, in the above embodiment, an aqueous solution of sulfuric acid and hydrogen peroxide was used for etching for selectively removing the AlAs layer. However, it is desirable that the etching rate be high in selectivity with respect to the Al composition ratio. An aqueous solution of sulfuric acid and hydrogen peroxide, in which the etching rate sharply increases as the temperature increases, is optimal. As another etchant, an aqueous solution of ammonium hydroxide and hydrogen peroxide may be used.

In the above-described embodiment, the case where the heating temperature is set to 400 ° C. in the selective oxidation of the AlAs layer has been described. However, the present invention is not limited to this. Any condition can be used as long as it can be controlled to be a value. When the temperature is increased, the oxidation rate increases, and a desired oxidized region can be formed in a short time. However, about 400 ° C. was the most easily controlled temperature.

In the etching for forming the semiconductor pillar, in the case of wet etching, since the upper layer and the lower layer are exposed to different etching solutions, a so-called tapered shape whose area is increased toward the bottom of the semiconductor pillar is formed. Although there is a problem that it is difficult to form a semiconductor pillar having a small diameter, in the case of dry etching, if a reactive ion beam etching (RIBE) method or a reactive ion etching (RIE) method is used, the side wall of the semiconductor pillar becomes
A vertical or undercut shape can be adopted, and a semiconductor pillar having a small diameter can be easily formed. At this time, Cl ₂ , B
Cl ₃ , SiCl ₄ or a mixed gas of Ar and Cl ₂ is used.

The operation of the surface-emitting type semiconductor laser device thus manufactured is as follows. here,
The carriers injected into the quantum well layer emit light by electron-hole recombination, and the light is reflected by the upper and lower semiconductor multilayer reflective films, and laser oscillation occurs when the gain exceeds the loss. The laser light is emitted through the second upper multilayer reflective film provided in the window of the electrode provided on the surface of the substrate. This shape has a rectangular shape having a ratio of the major axis to the minor axis of 5: 1. None, to form a flat beam as shown in FIGS.

Next, a surface emitting semiconductor laser device and a method of manufacturing the same according to a second embodiment of the present invention will be described with reference to the drawings. In the first embodiment, the second upper semiconductor multilayer reflective film 5 is formed so as to protrude from the upper surface of the prismatic light control region 7, but in this example, the second upper semiconductor multilayer reflective film 5a is formed. The surroundings are selectively oxidized to form a third oxide film 5s, which is a region having a different refractive index.

In this structure, in addition to the effect of the first embodiment, by adjusting the size of the region remaining without being oxidized, the effect that the shape of the output beam can be easily adjusted is exhibited.

Next, a surface emitting semiconductor laser device according to a third embodiment of the present invention and a method of manufacturing the same will be described with reference to the drawings.

In the first and second embodiments, the columnar light control region is formed by etching, but in this example, the current confinement layer 14 is left with a rectangular opening H by proton implantation as shown in FIG. The p-type upper semiconductor multilayer reflective film 5 is formed around the upper semiconductor multilayer reflective film 5 by diffusing a p-type impurity such as zinc. The upper semiconductor multilayer reflective film 5 is surrounded by an impurity diffusion region 15 having a different refractive index from that of the upper semiconductor multilayer reflective film 5. Is configured. This impurity diffusion region also serves as a current injection layer, and a p-side electrode 6 is formed on the upper layer.

The state of each layer and other portions are formed in the same manner as in the first and second embodiments.

In this structure, in addition to the effects of the first embodiment, the difference in the refractive index between the mountain 15 for writing impurities and the p-type upper multilayer reflection film 5 through which light is guided can be further reduced. This produces an effect that an output beam having a larger diameter can be easily obtained.

As shown in FIG. 7, such a surface-emitting type semiconductor laser device is arranged in an array such that the short axis of a rectangular light-emitting pattern p is aligned with the direction of n. Is formed.

As shown in FIG. 8, it is also possible to form a two-dimensional surface emitting semiconductor laser device by arranging such surface emitting semiconductor laser elements two-dimensionally. At this time, by forming the axes n and m connecting the closest patterns at a predetermined angle, the patterns can be arranged more closely so that light irradiation can be performed uniformly.

Next, this surface-emitting type semiconductor laser device is constituted by arranging elements in a one-dimensional array, and is projected onto the photoreceptor surface using a main-scanning magnifying optical system and a sub-scanning magnifying optical system. Is shown in FIG. As is clear from this figure, the light emitting pattern p formed by the surface emitting laser array 100 is made elliptical, and the flatness (length in the main scanning direction: p1, length in the sub-scanning direction: p2) of the light emitting pattern p is determined by light exposure. A perfect circle on the surface of the body 13 (length in the main scanning direction: L1, length in the sub scanning direction: L
2, L1 = L2) according to the magnification ratio of the optical system. Here, when the emission pattern is 5 μm in the longitudinal direction and 1 μm in the lateral direction, the magnification of the main scanning direction optical system 21 is 5 times and the magnification of the sub-scanning direction optical system 22 is 2 times.
By setting it to be 5 times and p1 / p2 = 5, it is possible to obtain a substantially perfect beam shape on the photoconductor 13 on the projection surface.

As a result, the anisotropy of the depth of focus can be minimized, the precision required for the alignment is suppressed, and the beam diameter projected on the photoreceptor surface is reduced due to misalignment such as eccentricity of the photoreceptor drum. Variation can be prevented from being reduced.

Needless to say, the present invention can be realized by another method within a range satisfying the constitutional requirements of the present invention.

[0053]

As described above, according to the present invention, when magnification is made at a predetermined magnification in the main scanning direction and magnification or reduction is made at a lower magnification in the sub-scanning direction, the magnification in each direction is reduced. The beam is formed into a flat shape so that the beam becomes a perfect circle on the surface of the photoconductor, thereby increasing the depth of focus. Variations in beam diameter caused by misalignment or other positional deviation can be reduced.

Furthermore, the plane of polarization of the emitted light can be stabilized in one direction, and when these elements are integrated on the same substrate, the planes of polarization of all the elements can be aligned in one direction without variation. Also, even if the injection current is increased, the diameter of the columnar light control region can be made sufficiently large compared to the shape of the light transmission region, thereby suppressing heat generation and without deteriorating light output characteristics over a wide output range. The polarization plane can be stabilized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a displacement from a focal position and a change in a beam diameter.

FIG. 2 is a diagram showing a surface-emitting type semiconductor laser device according to a first embodiment of the present invention;

FIG. 3 is a diagram showing contour lines of a beam intensity profile when a rectangular shape of a semiconductor multilayer reflective film is 5: 1.

FIG. 4 is a diagram showing a three-dimensional display of the beam intensity profile

FIG. 5 is a view showing a surface-emitting type semiconductor laser device according to a second embodiment of the present invention;

FIG. 6 is a diagram showing a surface emitting semiconductor laser device according to a third embodiment of the present invention;

FIG. 7 shows a surface emitting semiconductor laser device using the surface emitting semiconductor laser device of the present invention.
Conceptual diagram of dimensional array

FIG. 8 is a cross-sectional view of a surface emitting semiconductor laser device using the surface emitting semiconductor laser device of the present invention.
Conceptual diagram of dimensional array

FIG. 9 is a view showing a projection state of a beam in the main scanning direction and the sub-scanning direction in the semiconductor laser device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 n-type gallium arsenide (GaAs) substrate 2 n-type lower semiconductor multilayer reflective film 3 quantum well active layer 4 current confinement layer 5 p-type upper semiconductor multilayer reflective film 6 p-side electrode 7 light control region 8 second p-type upper semiconductor Multilayer reflective film 9 First insulating layer 10 Second insulating layer 13 Photoconductor 21 Main scanning enlargement scanning system 22 Subscanning enlargement scanning system 100 Surface emitting type semiconductor laser array surface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Izumi Iwasa 430 Sakai, Nakagawa-cho, Ashigarakami-gun, Kanagawa Green Tech Nakai Inside Fuji Xerox Co., Ltd.

Claims (10)

[Claims] 1. A vertical cavity surface emitting semiconductor laser device in which an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emits light in a direction perpendicular to the substrate. At least one of the lower semiconductor multilayer reflective films is configured to be longer in one direction in the substrate plane than in the other direction, and the intensity pattern of the emission beam is configured to have directionality. Surface emitting semiconductor laser device. 2. A vertical cavity surface emitting semiconductor laser device wherein an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emits light in a direction perpendicular to the substrate. A surface-emitting type semiconductor laser device characterized in that it is configured to be longer in one direction in the substrate plane than in the other direction, and that the intensity pattern of the light-emitting beam is directional. 3. A vertical cavity surface emitting semiconductor laser device in which an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emits light in a direction perpendicular to the substrate. The current constriction region provided on the outer side of the lower semiconductor multilayer reflective film or between these and the active layer is configured to be longer in one direction in the substrate plane than in the other direction, and the intensity pattern of the emission beam is reduced. A surface-emitting type semiconductor laser device characterized by having a directivity. 4. The surface-emitting type semiconductor laser device according to claim 3, wherein said current confinement region is made of an AlAs oxide. 5. A vertical cavity surface emitting semiconductor laser device in which an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emits light in a direction perpendicular to the substrate. 2. The surface-emitting type semiconductor laser device according to claim 1, wherein at least one of the lower semiconductor multilayer reflection films is covered with a material having a lower effective refractive index. 6. A vertical cavity surface emitting type semiconductor laser device in which an active layer is sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emits light in a direction perpendicular to the substrate is formed in the substrate surface. 3. A surface-emitting type semiconductor laser array comprising: a plurality of surface-emitting type semiconductor laser arrays, wherein an intensity pattern of a light-emitting beam of each element has a directivity; 7. A vertical cavity surface emitting semiconductor laser device having an active layer sandwiched between upper and lower semiconductor multilayer reflective films on a semiconductor substrate and emitting light in a direction perpendicular to the substrate,
A surface-emitting type semiconductor laser array in which a plurality of surface-emitting type semiconductor laser arrays are arranged in an array on a substrate surface, wherein an intensity pattern of a light-emitting beam of each element is configured to have directionality. . 8. A laser light source; a first lens system for enlarging a beam emitted from the laser light source at a first magnification in a main scanning direction; and a first lens system for enlarging or reducing at a second magnification in a sub-scanning direction. And a drive scanning system that drives and scans a beam from the laser light source and guides the beam on a scanning surface via the first and second lens systems. And a vertical cavity surface emitting semiconductor laser device configured such that the intensity pattern of the light emitting beam of the device has directionality so that the beam becomes substantially a perfect circle on the scanning surface in accordance with the second magnification. A surface-emitting type semiconductor laser device comprising: a surface-emitting type semiconductor laser device in which a plurality of are arranged in an array on a substrate surface. 9. A laser light source, a first lens system for expanding a beam emitted from the laser light source at a first magnification in a main scanning direction, and a first lens system for expanding or reducing at a second magnification in a sub-scanning direction. A photosensitive member that forms an electrostatic latent line by being exposed by a beam; and a drive that scans a beam from the laser light source and guides the beam onto the photosensitive member surface via the first and second lens systems. A scanning system, and recording means for performing image recording based on the electrostatic latent image, wherein the laser light source adjusts the first and second magnifications so that the beam is substantially circular on the scanning surface. A vertical cavity surface emitting semiconductor laser device in which the intensity pattern of the light emitting beam of the device has directionality is arranged in an array on a substrate surface. Be composed of a semiconductor laser device Surface-emitting laser beam recording apparatus according to claim. 10. A laser beam emitted from a laser light source is enlarged and reduced at first and second magnifications in a main scanning direction and a sub-scanning direction via a first lens system and a second lens system, respectively. Driving and scanning this to form an electrostatic latent line on the surface of the photoreceptor; and a recording step of performing image recording based on the electrostatic latent image. The vertical cavity surface emitting type semiconductor laser device is configured such that the intensity pattern of the light emitting beam of the device has directionality so that the beam becomes substantially a perfect circle on the scanning surface according to the magnification of 2. A laser recording method comprising a surface-emitting type semiconductor laser device in which a plurality of semiconductor laser devices are arranged in an array on a substrate surface.