JP2004172340A - Surface emitting laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a surface emitting laser where a lateral mode can be controlled even when it has such a structure that an air gap is interposed between a semiconductor layer and a DBR layer. <P>SOLUTION: The surface emitting laser emitting a laser beam in the direction perpendicular to a growth layer is equipped with a substrate provided with an outlet through which light is derived, a first distributed reflection layer formed on the substrate, an active layer which is sandwiched between a first and a second spacer layer in a vertical direction and formed on the first distributed reflection layer, a tunnel junction formed at the center of the first upper spacer layer, a third spacer layer which is formed around and above the tunnel junction, a contact layer which is formed on the peripheral part on the third spacer, a first electrode formed on the contact layer, a second electrode which is formed on a part of the rear of the substrate excluding the light outlet, and a second distributed reflection layer which faces the third spacer layer through an air gap. In the surface emitting laser, the film thickness of the third spacer layer at its center is so adjusted as to position the antinode of a standing wave at a boundary surface between the center of the third spacer layer and the air gap. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a surface emitting laser that emits a laser beam in a direction perpendicular to a growth layer, and in particular, can control a transverse mode even when an air gap is inserted between a semiconductor layer and a distributed reflection layer. Surface emitting laser.
[0002]
[Prior art]
Conventional VCSELs (Vertical Cavity Surface Emitting Lasers) have a structure in which an active layer and a cladding layer are sandwiched between reflection layers formed of a multilayer film or the like, and are used as a light source for optical communication or a light source for optical measurement. Prior art documents relating to a surface emitting laser which is used and which can be particularly applied to wavelength division multiplexing communication such as WDM (Wavelength Division Multiplexing) include the following.
[0003]
[Patent Document 1]
JP 08-213702 A [Patent Document 2]
Japanese Patent Application Laid-Open No. 2000-277853 [Patent Document 3]
Japanese Patent Application Laid-Open No. 2002-134835 [Non-Patent Document 1]
M. Ortsiefer et. al. , Appl. Phys. Lett vol. 76 pp. 2178-2181 (2000)
[Non-patent document 2]
G. FIG. R. Hadley et. al. , IEEE J. et al. Quantum Electronics 32 pp. 607-616 (1996)
[0004]
FIG. 5 is a cross-sectional view showing an example of such a conventional surface emitting laser, which is described in “M. Ortsiefer et. Al., Appl. Phys. Lett vol. 76 pp. 2178-2181 (2000)”. It is a thing.
[0005]
In FIG. 5, 1 denotes an n-type distributed Bragg Reflector (hereinafter referred to as DBR layer) formed of InAlAs / InGaAlAs, 2 and 4 denote a spacer layer, 3 denotes a quantum well, and the like. The active layer 5 is a p-type tunnel junction layer doped with a high concentration of p-type impurities, 6 is an n-type tunnel junction layer doped with a high concentration of n-type impurities, 7 is n-type InP or the like. A low refractive index layer, 8 is a mirror layer, 9 is a contact layer, 10 is an upper electrode, 11 is a heat sink, and 12 is a lower electrode.
[0006]
A lower spacer layer 2, an active layer 3, and an upper spacer layer 4 are sequentially formed on the DBR layer 1 (the lower side in FIG. 5, but the description will be made upside down in the following description of the formation process). The p-type tunnel junction layer 5 and the n-type tunnel junction layer 6 are sequentially formed on the upper spacer layer 4 to form a tunnel junction.
[0007]
A part of the p-type tunnel junction layer 5 and the n-type tunnel junction layer 6 are formed so that such a tunnel junction is formed only on the n-type DBR layer 1 and only at the central portion. The surrounding portions shown as "CI01" and "CI02" in FIG. 5 are removed by etching.
[0008]
Thereafter, a low-refractive index layer 7 of InP or the like is formed on the n-type tunnel junction layer 6 and the p-type tunnel junction layer 5 that has appeared on the surface in the etching step.
[0009]
Then, a mirror layer 8 constituting an upper mirror is formed on the low refractive index layer 7 and at the center in the center, and a contact layer 9 is formed around the mirror layer 8. An insulating film is formed on the side surfaces of the tunnel junction layer 6 and the low refractive index layer 7.
[0010]
An upper electrode 10 is formed so as to be connected to the contact layer 9, and a heat sink 11 is formed on the surface and side surfaces of the low refractive index layer 7. Further, a lower electrode 12 is formed on the back surface of the DBR layer 1.
[0011]
Here, the operation of the conventional example shown in FIG. 5 will be described with reference to FIG. However, in the description of the operation using FIG. 6, the description is made with the DBR layer 1 as the upper part. FIG. 6 is an explanatory diagram showing an example of the flow of the injection current.
[0012]
When a voltage is applied between the upper electrode 12 and the lower electrode 10, a current flows from the lower electrode 10 to the upper electrode 12 as shown in "CR11" in FIG. 6 and "CR12" in FIG. Flows through the tunnel junction formed in the substrate to cause current confinement.
[0013]
At this time, holes and electrons are coupled to each other in the active layer 4 having the narrowest band gap, and light is emitted. The light is amplified by an optical resonator formed between the DBR layer 1 and the mirror layer 8, and the DBR is amplified. The laser light is output from the portion on the layer 1 side where there is no upper electrode 12, as indicated by "LR11" in FIG.
[0014]
On the other hand, a high refractive index material is used for the tunnel junction, and a low refractive index layer 7 is formed around the tunnel junction, so that an equivalent refractive index difference “Δn _eff ” occurs between the two.
[0015]
Such an equivalent refractive index difference “Δn _eff ” is “λ” for the resonance wavelength at the tunnel junction, “Δλ” for the difference between the resonance wavelengths of the tunnel junction and the peripheral portion, and “n _eff ” for the equivalent refractive index. "
Δn _eff / n _eff = Δλ / λ (1)
Is represented by
[0016]
That is, by the equivalent refractive index “n _eff ”, the laser light that resonates in the above-described optical resonator is confined in the tunnel junction, and the light intensity distribution of the laser light of the surface emitting laser is maximized in the center (tunnel junction). Therefore, the lateral mode control can be performed.
[0017]
[Problems to be solved by the invention]
However, in the conventional surface emitting laser shown in FIG. 5, in order to simultaneously perform both current confinement and light confinement in the tunnel junction, the films of the heavily doped tunnel junction layers 5 and 6 to be formed must be formed. There is a problem that the thickness and composition are restricted.
[0018]
In other words, it is said that high concentration doping increases the light absorption of light in that part, so we want to lower the doping concentration, but we need high concentration doping to reduce the voltage drop at the tunnel junction. There will be a trade-off relationship.
[0019]
Therefore, if high-concentration doping is performed for current confinement or light confinement, the light absorption of the resonating laser light increases, and the light absorption of the tunnel junction becomes larger than that of the periphery of the tunnel junction. In other words, the light intensity distribution of the laser light of the surface emitting laser becomes small in the central portion (tunnel junction portion), which is disadvantageous for the transverse mode control.
[0020]
Further, in order to make the wavelength of the laser light variable in the conventional surface emitting laser shown in FIG. 5, an air gap is inserted between the spacer layer 2 and the DBR layer 1, and the upper mirror DBR layer 1 is movable. However, since a structure for supporting the DBR layer is required, it is difficult to extract the light output.
[0021]
On the other hand, when an air gap having a low refractive index is inserted between the semiconductor layer (the low refractive index layer 7 or the like) and the mirror layer 8, the transverse mode control may become unstable. There was the problem I said.
Therefore, an object of the present invention is to realize a surface emitting laser capable of controlling a transverse mode even when an air gap is inserted between a semiconductor layer and a DBR layer.
[0022]
[Means for Solving the Problems]
In order to achieve such an object, the invention according to claim 1 of the present invention is:
In a surface emitting laser that emits laser light in a direction perpendicular to the growth layer,
A substrate having a light extraction port, a first distributed reflection layer formed on the substrate, and a first and second spacer layer sandwiched from above and below and formed on the first distributed reflection layer An active layer, a tunnel junction formed at the center of the upper first spacer layer, a third spacer layer formed around and above the tunnel junction, and a third spacer layer formed on the third spacer layer. A contact layer formed on a peripheral portion of the first electrode, a first electrode formed on the contact layer, and a second electrode formed on a back surface of the substrate other than the light extraction port; A second distributed reflection layer facing the third spacer layer via an air gap;
By adjusting the thickness of the central portion of the third spacer layer so that the antinode of the standing wave is located at the boundary between the central portion of the third spacer layer and the air gap, the air gap is reduced. Even in the case of a configuration in which it is inserted between the optical fiber and the distributed reflection layer, the lateral mode control can be performed.
[0023]
The invention according to claim 2 is
In a surface emitting laser that emits laser light in a direction perpendicular to the growth layer,
A substrate having a light extraction port, a first distributed reflection layer formed on the substrate, and a first and second spacer layer sandwiched from above and below and formed on the first distributed reflection layer An active layer, a third spacer layer formed on the first spacer layer above and having a peripheral portion selectively oxidized, a contact layer formed on the peripheral portion on the third spacer layer, A first electrode formed on the contact layer, a second electrode formed on a back surface of the substrate other than the light extraction port, and an air gap with the third spacer layer. A second distributed reflection layer so as to face each other,
By adjusting the thickness of the central portion of the third spacer layer so that the antinode of the standing wave is located at the boundary between the central portion of the third spacer layer and the air gap, the air gap is reduced. Even in the case of a configuration in which it is inserted between the optical fiber and the distributed reflection layer, the lateral mode control can be performed.
[0024]
The invention according to claim 3 is
The surface emitting laser according to claim 2,
Since the insulating oxide is distributed around the third spacer layer, lateral mode control can be achieved even when an air gap is inserted between the spacer layer and the distributed reflection layer. Will be possible.
[0025]
The invention according to claim 4 is
The surface emitting laser according to any one of claims 1 to 3,
By adjusting the film thickness of the peripheral portion of the third spacer layer so that the node of the standing wave is located at the boundary between the peripheral portion of the third spacer layer and the air gap, the air gap is reduced. Even in the case of a configuration in which it is inserted between the optical fiber and the distributed reflection layer, the lateral mode control can be performed.
[0026]
The invention according to claim 5 is
The surface emitting laser according to any one of claims 1 to 4,
When a step between a central portion of the third spacer layer and a peripheral portion of the third spacer layer is formed by etching, an air gap is inserted between the spacer layer and the distributed reflection layer. Even in this case, the lateral mode control becomes possible.
[0027]
The invention according to claim 6 is
The surface emitting laser according to claim 1 or 4,
A step formed on the surface of the third spacer layer corresponding to a step formed between a tunnel junction formed at a center part on the first spacer layer and a peripheral part, the center part of the third spacer layer; By providing a step with the peripheral portion of the third spacer layer, the transverse mode can be controlled even when the air gap is inserted between the spacer layer and the distributed reflection layer.
[0028]
The invention according to claim 7 is
A surface emitting laser according to any one of claims 1 to 6,
The second distributed reflection film is formed by semiconductor fine processing technology and is made movable, so that the oscillation wavelength of laser light can be made variable.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing the configuration of an embodiment of the surface emitting laser according to the present invention.
[0030]
In FIG. 1, 13 is an n-type InP substrate, 14 is a distributed Bragg Reflector (hereinafter referred to as DBR layer) formed of n-type InGaAsP and n-type InP, and 15 is n-type InAlAs. The formed spacer layer, 16 is an active layer using a multiple quantum well (Multi Quantum Well) formed of InGaAlAs, 17 is a spacer layer formed of p-type InAlAs, and 18 is a p-type impurity with a high concentration. P-type tunnel junction layer formed of doped InGaAlAs; 19, an n-type tunnel junction layer formed of InGaAlAs doped with a high concentration of n-type impurities; 20, a spacer formed of n-type InP Layer, 21 is a contact layer formed of n-type InGaAsP, and 22 is an upper layer. An electrode, 23 is a DBR layer, 24 is a membrane formed of Si, and 25 is a lower electrode.
[0031]
A lower DBR layer 14 is formed on the n-type InP substrate 13, and a lower spacer layer 15, an active layer 16 and an upper spacer layer 17 are sequentially formed on the DBR layer 14.
[0032]
A p-type tunnel junction layer 18 and an n-type tunnel junction layer 19 are sequentially formed on the upper spacer layer 17 to form a tunnel junction, and a part of the p-type tunnel junction layer 18 and an n-type tunnel junction are formed. The surrounding portion of the bonding layer 19 shown as “CI21” in FIG. 1 and “CI22” in FIG. 1 is removed by etching or the like.
[0033]
Thereafter, a spacer layer 20 is sequentially formed on the n-type tunnel junction layer 19 and the p-type tunnel junction layer 18 which has appeared on the surface in the etching step. The spacer layer 20 is surrounded by a portion indicated by "CI23" in FIG. 1 and "CI24" in FIG. 1, in other words, on the spacer layer 20, is surrounded by an upper portion (center portion) of the tunnel junction portion and a peripheral portion. The part to be removed is removed by etching.
[0034]
A contact layer 21 is formed on the spacer layer 20 at a peripheral portion, and an upper electrode 22 is formed on the contact layer 21.
[0035]
Then, a membrane 24 is formed above the spacer layer 20 without being in contact with the spacer layer 20, and a DBR layer 23 is formed below the membrane 24, in other words, on a surface facing the spacer layer 20, FIG. An air gap as shown by "AG21" is formed.
[0036]
On the other hand, the n-type InP substrate 13 is a back surface, and a portion indicated by “AR21” in FIG. 1 is removed as a light extraction port to the surface of the DBR layer 14 by etching. An electrode 25 is formed.
[0037]
Here, the operation of the embodiment shown in FIG. 1 will be described with reference to FIGS. 2, 3 and 4. FIG. FIG. 2 is an explanatory diagram showing an example of the flow of the injection current, and FIG. 3 is a characteristic curve diagram showing an example of the light intensity distribution of the laser beam when the node of the standing wave is located at the interface between the spacer layer 20 and the air gap. FIG. 4 is a characteristic curve diagram showing an example of the light intensity distribution of the laser beam when the antinode of the standing wave is located at the boundary surface between the spacer layer 20 and the air gap.
[0038]
When a voltage is applied between the upper electrode 22 and the lower electrode 25, a tunnel is formed from the upper electrode 22 as shown by "CR31" in FIG. 2 and "CR32" in FIG. It flows through the junction, causing current constriction.
[0039]
At this time, holes and electrons are coupled to each other in the active layer 16 having the narrowest band gap, and light is emitted. The light is amplified by an optical resonator formed between the DBR layer 14 and the DBR layer 23, and the light is emitted. The laser light is output from the light extraction port on the side 14 from which the n-type InP substrate 13 has been removed, as indicated by "LR31" in FIG.
[0040]
The thicknesses of the upper spacer layer 17 and the lower spacer layer 15 are adjusted so that the antinode of the standing wave comes to the active layer 16.
[0041]
Also, the membrane 24 is moved by MEMS (micro electro-mechanical systems: a minute mechanical system in which a movable part and an electronic circuit are integrated by a semiconductor fine processing technology), and the distance between the spacer layer 20 and the DBR layer 23 (see FIG. 1). By adjusting the gap of the air gap shown in "AG21", the oscillation wavelength of the laser light is made variable.
[0042]
Further, the thickness and the step of the spacer layer 20 are adjusted so that the antinode of the standing wave comes to the boundary surface between the central portion (convex portion) of the spacer layer 20 and the air gap, and the central portion of the spacer layer 20. It is adjusted so that the node of the standing wave comes to the boundary surface between the portion (recess) surrounded by the peripheral portion and the air gap.
[0043]
For example, as can be seen from the characteristic curve indicated by "CH41" in FIG. 3, a case where the node of the standing wave is located at the boundary surface between the portion (recess) surrounded by the central portion and the peripheral portion of the spacer layer 20 and the air gap. The light intensity in the lower DBR layer 14 shown by “DB41” in FIG. 3 and the semiconductor layers of the spacer layers 15 to 20 including the active layer 16 shown by “QW41” in FIG. 3 are small. 3, the light intensity in the air gap indicated by “AG41” increases, and confinement of the resonating laser light in the active layer 16 decreases.
[0044]
On the other hand, for example, as can be seen from the characteristic curve indicated by “CH51” in FIG. 4, when the antinode of the standing wave is located at the boundary surface between the central portion (convex portion) of the spacer layer 20 and the air gap, FIG. The light intensity in the air gap indicated by “AG51” in the middle is low, and conversely, the light intensity in the semiconductor layers of the spacer layers 15 to 20 including the active layer 16 indicated by “QW51” in FIG. The confinement of the resonating laser light at the time increases.
[0045]
That is, the laser light resonating with the optical resonator is confined in the tunnel junction by the equivalent refractive index difference from the spacer layer 20 formed around the tunnel junction in the same manner as in the conventional example. In the (projection), the confinement of the resonating laser light increases. On the other hand, in the portion (recess) surrounded by the central portion and the peripheral portion of the spacer layer 20, the confinement of the resonating laser light decreases, and the surface emitting laser laser Since the light intensity distribution of the light becomes maximum at the central portion (convex portion (tunnel junction portion)), lateral mode control becomes possible.
[0046]
As a result, the antinode of the standing wave is positioned at the boundary surface between the central portion (convex portion) of the semiconductor layer (spacer layer 20) and the air gap, and is surrounded by the central portion and the peripheral portion of the spacer layer 20. By adjusting the film thickness of each part of the spacer layer 20 so that the node of the standing wave is located at the boundary surface between the part (concave part) and the air gap, the air gap is formed by the semiconductor layer (spacer layer 20) and the DBR layer 23. The horizontal mode control can be performed even in the case of a configuration in which it is inserted between the horizontal mode and the vertical mode.
[0047]
In the embodiment shown in FIG. 1, the thickness and the step of the spacer layer 20 are adjusted so that a standing wave of a standing wave is formed on a boundary surface between a portion (recess) surrounded by a central portion and a peripheral portion of the spacer layer 20 and the air gap. Although it is described that the node is adjusted, the portion other than the antinode of the standing wave comes to the boundary surface between the portion (recess) surrounded by the central portion and the peripheral portion of the spacer layer 20 and the air gap. You can adjust it.
[0048]
In the embodiment shown in FIG. 1, a step (unevenness) is formed by etching between a central portion (convex portion) of the spacer layer 20 and a portion (concave portion) surrounded by the central portion and the peripheral portion of the spacer layer 20. However, the present invention is not limited to this, and the steps (irregularities) of the spacer layer 20 may be formed using the steps of the tunnel junction.
[0049]
For example, when the spacer layer 20 is formed by sequentially laminating crystals on the tunnel junction layers 18 and 19, the step of the tunnel junction is transmitted, and the step corresponding to the step of the tunnel junction is formed on the surface of the spacer layer 20. Therefore, such a step may be used.
[0050]
Further, in the embodiment shown in FIG. 1, the current confinement is realized by the tunnel junction. However, the method for realizing the current confinement is not limited to the method using the tunnel junction. For example, the selective oxidation of InAlAs May be used.
[0051]
For example, without using the tunnel junction layers 18 and 19, the spacer layer 17 made of InAlAs is formed up to the upper surface portion of the tunnel junction layer 19, and oxygen is permeated from the peripheral portion to selectively oxidize Al of InAlAs, Aluminum oxide (Al ₂ O ₃ ), which is an oxide having an insulating property, is distributed around the periphery.
[0052]
With such a configuration, the current supplied from the electrodes 22 to avoid aluminum oxide formed on the peripheral portion (Al 2 _{O 3)} aluminum oxide (Al 2 _{O 3)} to flow through the central portion which is not distributed And current constriction can be realized.
[0053]
Further, although the wavelength tunable laser is realized by making the upper DBR layer 23 movable, it goes without saying that the upper DBR layer 23 may be fixed and a fixed wavelength laser may be used. In this case, a dielectric film such as SiO ₂ may be used instead of the air gap indicated by “AG21” in FIG.
[0054]
Further, another gas or liquid may be sealed in the air gap instead of the air.
[0055]
Further, in the embodiment shown in FIG. 1, it is described that the second distributed reflection layer is formed on the membrane via an air gap so as to face the third spacer layer. It is not done.
[0056]
Further, in the embodiment shown in FIG. 1, it is described that the adjustment is performed so that the node of the standing wave comes to the boundary surface between the portion (recess) surrounded by the central portion and the peripheral portion of the spacer layer 20 and the air gap. However, the interface between the portion where the electrode 22 is formed and the air gap may also be adjusted so that a node of the standing wave comes.
[0057]
That is, the antinode of the standing wave is positioned at the boundary between the central portion (convex portion) of the semiconductor layer (spacer layer 20) and the air gap, and the boundary between the peripheral portion (concave portion) of the spacer layer 20 and the air gap. The thickness of each part of the spacer layer 20 may be adjusted so that the node of the standing wave is located on the surface.
[0058]
【The invention's effect】
As is apparent from the above description, the present invention has the following effects.
According to the first, second, third, fourth and fifth aspects of the present invention, the antinode of the standing wave is positioned at the boundary between the central portion (convex portion) of the spacer layer and the air gap. By adjusting the film thickness of each part of the spacer layer so that the node of the standing wave is located at the boundary surface between the part (recess) surrounded by the center part and the peripheral part of the spacer layer and the air gap, the air gap is reduced. Even in the case where the structure is inserted between the spacer layer and the DBR layer, the transverse mode can be controlled.
[0059]
Further, according to the invention of claim 7, the oscillation wavelength of the laser light can be made variable by making the membrane movable by MEMS and adjusting the distance between the spacer layer and the DBR layer.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a configuration of an embodiment of a surface emitting laser according to the present invention.
FIG. 2 is an explanatory diagram showing an example of a flow of an injection current.
FIG. 3 is a characteristic curve diagram illustrating an example of a light intensity distribution of a laser beam when a node of a standing wave is located at a boundary surface between a spacer layer and an air gap.
FIG. 4 is a characteristic curve diagram showing an example of a light intensity distribution of a laser beam when an antinode of a standing wave is located at a boundary surface between a spacer layer and an air gap.
FIG. 5 is a configuration sectional view showing an example of a conventional surface emitting laser.
FIG. 6 is an explanatory diagram showing an example of a flow of an injection current.
[Explanation of symbols]
1,14,23 Distributed reflection layer (DBR layer)
2, 4, 15, 17, 20 Spacer layer 3, 16 Active layer 5, 6, 18, 19 Tunnel junction layer 7 Low refractive index layer 8 Mirror layer 9, 21 Contact layer 10, 12, 22, 25 Electrode 11 Heat sink 13 InP substrate 24 membrane

Claims (7)

In a surface emitting laser that emits laser light in a direction perpendicular to the growth layer,
A substrate having a light extraction port,
A first distributed reflection layer formed on the substrate;
An active layer sandwiched from above and below by the first and second spacer layers and formed on the first distributed reflection layer;
A tunnel junction formed at a central portion on the upper first spacer layer;
A third spacer layer formed around and above the tunnel junction;
A contact layer formed in a peripheral portion on the third spacer layer;
A first electrode formed on the contact layer;
A second electrode formed on a portion of the back surface of the substrate other than the light extraction port;
A second distributed reflection layer facing the third spacer layer via an air gap;
A surface emitting laser, wherein the thickness of the central portion of the third spacer layer is adjusted such that the antinode of the standing wave is located at the boundary between the central portion of the third spacer layer and the air gap. . In a surface emitting laser that emits laser light in a direction perpendicular to the growth layer,
A substrate having a light extraction port,
A first distributed reflection layer formed on the substrate;
An active layer sandwiched from above and below by the first and second spacer layers and formed on the first distributed reflection layer;
A third spacer layer formed on the upper first spacer layer and having a peripheral portion selectively oxidized;
A contact layer formed in a peripheral portion on the third spacer layer;
A first electrode formed on the contact layer;
A second electrode formed on a portion of the back surface of the substrate other than the light extraction port;
A second distributed reflection layer facing the third spacer layer via an air gap;
A surface emitting laser, wherein the thickness of the central portion of the third spacer layer is adjusted such that the antinode of the standing wave is located at the boundary between the central portion of the third spacer layer and the air gap. . The surface emitting laser according to claim 2, wherein an oxide having an insulating property is distributed in a peripheral portion of the third spacer layer. 2. The film thickness of a peripheral portion of the third spacer layer is adjusted so that a standing wave node is located at a boundary surface between the peripheral portion of the third spacer layer and the air gap. The surface emitting laser according to claim 3. 5. The surface emitting laser according to claim 1, wherein a step between a central portion of the third spacer layer and a peripheral portion of the third spacer layer is formed by etching. A step formed on the surface of the third spacer layer corresponding to a step formed between a tunnel junction formed at a center part on the first spacer layer and a peripheral part, the center part of the third spacer layer; 5. The surface emitting laser according to claim 1, wherein the step is a step with a peripheral portion of the third spacer layer. The surface emitting laser according to claim 1, wherein the second distributed reflection film is formed by a semiconductor fine processing technique and is movable.

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