JP2015015356A - Wavelength variable device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength variable device in which an optical axis is easily adjusted.SOLUTION: The wavelength variable device in an embodiment includes a first reflection mirror formed in contact with a substrate, a resonator formed in contact with the first reflection mirror and including a light-emitting part, a contact layer formed in contact with the resonator, a support member in contact with the contact layer and formed symmetric around an optical axis of the light-emitting part, an elastically deformable second reflection mirror formed opposing to the resonator via the support member, and an optical filter formed in contact with the second reflection mirror. A contact area between the support member and the second reflection mirror is smaller than a contact area between the support member and the contact layer; and a maximum displacement part of the second reflection mirror and a light-transmitting part of the optical filter are present on the optical axis.

Description

  The present invention relates to a wavelength tunable device.

  A wavelength variable VCSEL (Vertical Cavity Surface Emitting Laser) capable of changing the oscillation wavelength uses a membrane for the wavelength variable portion in order to sweep the wavelength over a wide range.

  The reliability of the tunable VCSEL decreases as the center (maximum displacement portion) of the membrane that determines the oscillation wavelength deviates from the optical axis of the light emitting portion. For this reason, techniques for precisely aligning the light emitting part and the wavelength variable part are disclosed in many documents.

  A technique is disclosed in which the resonant frequency of the resonator is changed by controlling the position of the concave reflecting mirror, and the wavelength variable portion including the concave reflecting mirror and the light emitting portion including the surface emitting semiconductor laser are manufactured monolithically. (For example, refer to Patent Document 1).

  It is extremely difficult to obtain a wavelength tunable device in which the light emitting part and the wavelength variable part are precisely aligned (optical axis adjustment) so that the maximum displacement part of the membrane exists on the optical axis of the light emitting part.

  Even if the wavelength tunable device is manufactured by using the technique disclosed in Patent Document 1, the complexity of the manufacturing process cannot be avoided.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to obtain a wavelength tunable device in which the optical axis is easily adjusted.

  The wavelength tunable device according to the present embodiment is formed in contact with the first reflecting mirror formed in contact with the substrate, in contact with the first reflecting mirror, including the light emitting unit, and in contact with the resonator. A contact layer that is in contact with the contact layer and formed symmetrically across the optical axis of the light emitting portion, and a second reflecting mirror that is formed to face the resonator via the support member and is elastically deformable. An optical filter formed in contact with the second reflecting mirror, and a contact area between the support member and the second reflecting mirror is smaller than a contact area between the support member and the contact layer, and is on the optical axis. The requirement is that the maximum displacement portion of the second reflecting mirror and the light transmission portion of the optical filter exist.

  According to the embodiment of the present invention, it is possible to obtain a wavelength tunable device in which the optical axis is easily adjusted.

It is a figure which illustrates the wavelength variable device which concerns on embodiment. It is a graph which shows sectional drawing, light intensity, and a reflectance of the wavelength variable part which concerns on embodiment. It is a figure explaining the wavelength variable device which concerns on embodiment. It is a figure explaining the wavelength variable device which concerns on embodiment. It is a figure explaining a wavelength variable device. It is a figure which illustrates the membrane which concerns on embodiment. It is a figure which illustrates the membrane which concerns on embodiment. It is a figure which illustrates the membrane which concerns on embodiment. It is a graph which shows the relationship between an electrical potential difference and the amount of movement. It is a figure which illustrates the manufacturing method of the wavelength variable device which concerns on embodiment. It is a figure explaining the position of the standing wave in an electric field strength distribution, and the position of a resonator. It is a figure which illustrates the manufacturing method of the wavelength variable device which concerns on embodiment. It is a figure which illustrates the manufacturing method of the wavelength variable device which concerns on embodiment. It is a figure which illustrates the manufacturing method of the wavelength variable device which concerns on embodiment. It is a figure which illustrates the manufacturing method of the wavelength variable device which concerns on embodiment. It is a figure which illustrates the manufacturing method of the wavelength variable device which concerns on embodiment.

  In the present specification, the “membrane” refers to a structure that is so thin that its thickness is negligible with respect to the area and is elastically deformable (having an extremely thin film form and a beam form).

  In this specification, “monolithic” refers to a form in which a plurality of elements are integrally formed on a single semiconductor substrate.

[Configuration of wavelength tunable device]
FIG. 1 shows a wavelength tunable device according to this embodiment. FIG. 1A is a top view and FIG. 1B is a cross-sectional view.

  The wavelength tunable device 100 includes a substrate 101, a first reflecting mirror 102, a resonator 103, a contact layer 104, a support member 105, a second reflecting mirror (membrane) 106, an optical filter 107, 1 electrode 108, second electrode 109, and third electrode 110. The resonator 103 includes an active layer 111 and a current confinement layer 112.

  In the wavelength tunable device 100, the maximum displacement part of the membrane and the light transmission part of the optical filter 107 exist on the optical axis of the light emitting part α.

  The position of the light emitting portion α is controlled by the current confinement layer 112, and the light emitting portion α is formed at a position overlapping the current confinement portion β.

  The second reflecting mirror 106 is a membrane and functions as a part of the wavelength variable unit γ. Due to the displacement of the membrane, the interval between the second reflecting mirror 106 and the contact layer 104 changes, and the oscillation wavelength of the wavelength tunable device 100 is determined based on this interval.

  For example, part of the light incident from the substrate 101 side is absorbed by the substrate, the transmitted light resonates between the first reflecting mirror 102 and the second reflecting mirror 106, and only the laser light having a specific wavelength is obtained. The light is emitted from the wavelength tunable device 100 through the optical filter 107.

  The reflectivity of the first reflecting mirror 102 and the second reflecting mirror 106 is preferably higher. In particular, by increasing the reflectance of the first reflecting mirror 102, a large amount of incident light can be reflected, so that the light output of the wavelength tunable device 100 can be increased.

  The optical filter 107 is formed in contact with the second reflecting mirror 106, and controls the beam profile (light intensity distribution) of the laser light emitted from the wavelength variable device 100. The optical filter 107 is completely removed only on the optical axis of the light emitting portion, and has a shape that increases in thickness in a direction deviating from the optical axis (see FIG. 2A). With this shape, a laser beam with a good beam profile can be obtained.

  2B and 2C show the beam profile and reflectance distribution of the optical filter 107. FIG. It can be seen that the light intensity and the reflectance are maximized on the optical axis of the light emitting part. The light intensity and the reflectance can be controlled by appropriately adjusting the film thickness and shape when the optical filter 107 and the second reflecting mirror 106 are manufactured.

  In addition, when the light transmission part of the optical filter 107 does not exist on the optical axis of the light emitting part (see FIG. 3), the beam profile of the laser light is deteriorated.

  The second reflecting mirror 106 is formed to face the contact layer 104 with the support member 105 interposed therebetween. As shown in FIG. 4, the second reflecting mirror 106 includes a movable part X and a fixed part Y. The movable part X is elastically deformed, and the fixed part Y is fixed to the contact layer 104 via the support member 105. The smaller the contact area between the second reflecting mirror 106 and the support member 105, the wider the movable part X can be.

  The support member 105 is formed between the contact layer 104 and the second reflecting mirror 106. The support member 105 is preferably highly rigid. Since the support member 105 that supports the membrane is highly rigid, the reliability of the wavelength variable portion can be increased. The support member 105 preferably has a shape such that the contact area with the second reflecting mirror 106 is smaller than the contact area with the contact layer 104. The top surface shape is not limited to the circular shape as shown in FIG. 1, and may be a rectangular shape, a hexagonal shape, or the like. The cross-sectional shape is preferably such that the support member width A is narrower than the support member width B as shown in FIG. The movable portion X when the support member width A is narrower than the support member width B is wider than the movable portion X ′ when the support member width A ′ is equal to the support member width B ′ (see FIG. 5). Therefore, the wavelength sweep range of the wavelength tunable device 100 can be expanded. The shape of the support member can be controlled by devising the shape of the membrane or by appropriately adjusting the etchant used in the wet etching step (described later).

  For example, as shown in FIG. 6, the second reflecting mirror 106 has a width w1 (a width of a portion not overlapping the support member 105) in the direction perpendicular to the longitudinal direction of the second reflecting mirror 106. The shape is preferably narrower than the width of the portion overlapping the support member 105. The second reflecting mirror 106 is preferably shaped so as to have symmetry with respect to the optical axis of the light emitting portion. Since the support member 105 is formed using the shape of the second reflecting mirror 106, the second reflecting mirror 106 has such a shape, and thus is symmetrical (symmetrical) with the optical axis of the light emitting unit interposed therebetween. Support member 105 can be formed at a specific position and symmetrical shape (a semiconductor layer to be a support member later can be left symmetrically with the optical axis in between by a wet etching process). it can). Since the supporting member 105 has such a shape, the maximum displacement portion (center of the membrane) of the membrane can be present on the optical axis of the light emitting portion, so that the reliability of the wavelength tunable device 100 can be improved. Furthermore, by providing the light transmission part of the optical filter on the optical axis of the light emitting part, it is possible to realize the wavelength tunable device 100 in which the optical axis is easily adjusted.

  The shape of the second reflecting mirror 106 is not limited to the shape shown in FIG. For example, as shown in FIG. 7, the shape may be extended in three directions from the center of the wavelength tunable device 100, or may be extended in four directions from the center of the wavelength tunable device 100 as shown in FIG. It may be a shape. Moreover, it is not limited to 3 directions and 4 directions, The shape extended | stretched to 5 directions or the direction of the number beyond it may be sufficient. In any case, in the direction perpendicular to the stretching direction, the width of the portion that overlaps the support member 105 is wider than the width of the portion that does not overlap the support member 105, and with respect to the optical axis. Any shape that has symmetry may be used.

[Membrane displacement and oscillation wavelength]
The wavelength tunable device 100 oscillates at a wavelength λ when a potential is applied between the first electrode 108 and the second electrode 109.

  When potentials having the same polarity are applied to the second electrode 109 and the third electrode 110, repulsive force acts between the second reflecting mirror 106 and the contact layer 104. The membrane is mechanically displaced toward the optical filter 107 and the distance between the two is increased. As a result, the resonator length set based on the distance between the first reflecting mirror 102 and the second reflecting mirror 106 is expanded, and the oscillation wavelength is changed. If the oscillation wavelength at this time is λ1, the relationship of λ <λ1 is established.

  On the other hand, when potentials having different polarities are applied to the second electrode 109 and the third electrode 110, an attractive force acts between the second reflecting mirror 106 and the contact layer 104. The membrane is mechanically displaced toward the support member 105 and the distance between the two is reduced. As a result, the resonator length set based on the distance between the first reflecting mirror 102 and the second reflecting mirror 106 is reduced, and the oscillation wavelength is changed. If the oscillation wavelength at this time is λ2, the relationship λ> λ2 is established.

  The wavelength tunable device 100 can adjust the interval by changing the potential applied to the electrodes, and can control the oscillation wavelength of the laser light emitted from the device.

  The relationship between the potential and the amount of movement in the membrane will be described with reference to FIG. A case where a negative potential (for example, potential Vm) is applied to the membrane and a positive potential (for example, potential Vc) is applied to the contact layer will be described. As the absolute value of the potential difference (Vc−Vm) between the potential Vm and the potential Vc increases, the amount of movement of the membrane increases. When the potential difference (Vc−Vm) becomes larger than the absolute value K, the movement amount of the membrane is saturated. This is due to the physical rigidity of the membrane. That is, when the potential difference (Vc−Vm) satisfies −K or more and + K or less, the membrane moves normally. Using a membrane in the saturation range shortens the mechanical life of the membrane. As the absolute value K is increased, the movable range of the membrane can be expanded, and the driving voltage of the wavelength tunable device 100 can be reduced.

[Manufacturing method of wavelength tunable device]
A method for manufacturing the wavelength tunable device 100 will be described with reference to FIGS.

  First, as shown in FIG. 10, on a substrate 101, a first reflecting mirror layer 201, a resonator 202, a contact layer 203, a first semiconductor layer 204, a second reflecting mirror layer 205, A second semiconductor layer 206 is sequentially stacked. The resonator 202 includes an active layer 207, a high Al composition layer 208, and the like. The active layer 207, the high Al composition layer 208, and the contact layer 203 are preferably laminated at positions as shown in FIG. For example, when the resonator length of the entire resonator 202 is set to two oscillation wavelengths, the position of the active layer 207 matches the position of the antinode of the standing wave in the electric field intensity distribution. It can be adjusted and laminated so that the position of the wave node and the position of the high Al composition layer 208 coincide, and the position of the antinode of the standing wave and the position of the surface of the contact layer 203 coincide. preferable.

  Examples of the material of the substrate 101 include a GaAs substrate.

  Examples of the material of the resonator 202 include a GaInAs material, a GaAs material, and an AlAs material.

  Examples of the material of the contact layer 203 include GaAs-based materials.

As materials for the first semiconductor layer 204 and the second semiconductor layer 206, the same material may be used, or different materials may be used. When the same material is used, it is preferable to use an AlGaInP _x As _(1-x) (x ≠ 0) material or the like. In the AlGaInP _x As _(1-x) (x ≠ 0) -based material, it is preferable that the As composition is larger than the P composition. That is, x >> 0 is preferable. By reducing the P composition, the crystal quality in the first semiconductor layer 204 and the second semiconductor layer 206 can be improved. Note that by using the same material, wet etching can be performed on the first semiconductor layer 204 and the second semiconductor layer 206 at the same time, so that the manufacturing process can be simplified and costs can be reduced.

When a different material is used, it is preferable to use an Al _x1 Ga _y1 In _(1-x1-y1) P-based material as the material of the second semiconductor layer 206, and the material of the first semiconductor layer 204 is Al it is preferable to use a _{x2 Ga y2 In (1-x2} -y2) P materials. x2 is preferably larger than x1. By using different materials, the etching rate can be individually controlled when wet etching is performed on the first semiconductor layer 204 and the second semiconductor layer 206. Therefore, by appropriately selecting the etchant or the like, the shape of the support member can be changed in design over a wide range, so that the degree of freedom in designing the wavelength tunable device 100 can be increased.

  As a material of the first reflecting mirror layer 201 and the second reflecting mirror layer 205, an AlGaAs material or the like can be used. In consideration of erosion with respect to an etchant used in a wet etching process to be described later, the material of the second reflecting mirror layer 205 in contact with the second semiconductor layer 206 needs to be appropriately selected.

For example, when the material of the second reflector layer 205 is an AlGaAs material and the material of the second semiconductor layer 206 is an AlGaInP _x As _(1-x) (x ≠ 0) material, HCl is used. By using the included etchant, the shape of the optical filter can be controlled with high accuracy. The etchant containing HCl has erosion with respect to the AlGaInP _x As _(1-x) material, but does not have erosion with respect to the AlGaAs material. Therefore, the etching of the second semiconductor layer 206 can proceed with high accuracy without eroding the second reflecting mirror layer 205 made of an AlGaAs-based material.

For example, when the material of the second reflecting mirror layer 205 is an AlGaInP _x As _(1-x) (x ≠ 0) material and the material of the second semiconductor layer 206 is an AlGaAs material, By using an etchant containing H ₂ SO ₄ and H ₂ O ₂ at the time of wet etching, the shape of the optical filter can be controlled with high accuracy. An etchant containing H ₂ SO ₄ and H ₂ O ₂ has erosion with respect to an AlGaAs-based material, but has erosion with respect to an AlGaInP _x As _(1-x) (x ≠ 0) -based material. No. Therefore, the etching of the second semiconductor layer 206 can proceed with high accuracy without eroding the second reflecting mirror layer 205 made of an AlGaInP _x As _(1-x) material.

  Next, as shown in FIG. 12, the photoresist layer is patterned on the surface of the second semiconductor layer 206 using a known photolithography method to form a resist pattern H for mesa post. The resonator 202, the contact layer 203, the first semiconductor layer 204, the second reflecting mirror layer 205, and the second semiconductor layer 206 that do not overlap the resist pattern H for mesa post are removed by dry etching or the like, and the mesa post 209 is removed. Form. In the dry etching, at least the portion reaching the high Al composition layer 208 may be removed.

  Next, the resist pattern H for mesa post is removed, and the mesa post 209 is heated at a high temperature in saturated water vapor. Thereby, the high Al composition layer is oxidized to form a current confinement layer.

  Next, as shown in FIG. 13, the photoresist layer is patterned on the surface of the second semiconductor layer 206 by using a known photolithography method to form a resist pattern I for the membrane.

  Next, as shown in FIG. 14, a part of the mesa post 209 that does not overlap with the membrane resist pattern I is removed by dry etching or the like until it reaches the contact layer.

  Next, as shown in FIG. 15, the resist pattern I for the membrane is removed, and the photoresist layer is patterned on the surface of the second semiconductor layer 206 using a known photolithography method, so that the optical filter for the optical filter is used. A resist pattern J is formed. Next, wet etching is performed on the first semiconductor layer and the second semiconductor layer using an appropriate etchant. The first semiconductor layer and the second semiconductor layer are simultaneously wet etched to form the support member 105 and the optical filter 107. Note that the first semiconductor layer and the second semiconductor layer may be sequentially wet-etched to form the support member 105 and the optical filter 107 individually.

In the wet etching step, an etchant is preferably selected as appropriate in consideration of materials used for the first semiconductor layer 204 and the second semiconductor layer 206. In particular, it is preferable to use an isotropic etchant. For example, when an AlGaAs-based material is used as the material of the first semiconductor layer 204 and the second semiconductor layer 206, the etchant includes a mixed solution containing H ₂ SO ₄ , H ₂ O ₂ , and H ₂ O, and an HF solution. It is preferable to use a mixed solution containing NH ₃ OH, H ₂ O ₂ , H ₂ O, or the like. For example, when a GaAs-based material is used as the material of the first semiconductor layer 204 and the second semiconductor layer 206, the etchant is a mixed solution containing HCl, HNO ₃ , H ₂ O ₂ , HF, H _2. It is preferable to use a mixed solution containing SO ₄ and H ₂ O ₂ or the like.

  Through the above steps, the first semiconductor layer 204, the second reflecting mirror layer 205, the second semiconductor layer 206, the contact layer 203, the resonator 202, and the first reflecting mirror layer 201 shown in FIG. The support member 105, the second reflecting mirror 106, the optical filter 107, the contact layer 104, the resonator 103, and the first reflecting mirror 102 shown in FIG. 15 can be formed.

  Next, the membrane resist pattern J is removed, and the first electrode 108, the second electrode 109, and the third electrode 110 are formed (see FIG. 1). Thereby, the wavelength tunable device 100 is completed.

  According to the manufacturing method described above, the wavelength tunable device 100 can be manufactured monolithically with the light emitting portion and the wavelength tunable portion, so that the manufacturing process can be prevented from becoming complicated and the yield can be improved. In addition, since the support member is formed symmetrically with the optical axis of the light emitting portion sandwiched through the wet etching process, the maximum displacement portion of the membrane can exist on the optical axis. Furthermore, by providing the light transmitting portion of the optical filter on the optical axis, it is possible to easily obtain a wavelength tunable device that adjusts the optical axis and emits good laser light.

  In addition, an example of a manufacturing method different from the above-described manufacturing method will be described. The wavelength tunable device can also be manufactured by simultaneously forming resist patterns for mesa posts, membranes, and optical filters, and removing each pattern sequentially each time each part is formed. The alignment accuracy with the optical axis depends on the processing accuracy of the photomask for forming the resist pattern. If the processing accuracy of the photomask can be increased, a wavelength tunable device with high luminous efficiency and reliability can be realized.

  A specific manufacturing method will be described with reference to FIGS.

  First, a first reflecting mirror layer, a resonator, a contact layer, a first semiconductor layer, a second reflecting mirror layer, and a second semiconductor layer are sequentially stacked on a substrate. Up to this step, the manufacturing method is the same as that described above.

  Next, a protective film is formed on the surface of the second semiconductor layer. As the material for the protective film, a material having selectivity for the photoresist is used. For example, materials such as SiN and SiO can be used.

  Next, a mesa post resist pattern, a membrane resist pattern, and an optical filter resist pattern are simultaneously formed on the protective film. Next, the protective film is patterned with hydrofluoric acid or the like to remove the resist pattern. Thereby, the patterning for the outer shape is performed on the protective film, and the mesa post outer shape protective film, the membrane outer shape protective film, and the optical filter outer shape protective film are formed (see FIG. 16A).

  Next, the protective resist 1 is formed on the mesa post outer shape protective film so that the boundary exists (see FIG. 16B). Next, dry etching is performed to form a mesa post.

  Next, the protective resist 1 is removed, and the protective resist 2 is formed on the membrane outer shape protective film so that there is a boundary (see FIG. 16C). Next, dry etching is performed to form a membrane. Next, wet etching is performed on the first semiconductor layer to form a support member.

  Next, the protective resist 2 is removed (see FIG. 16D), and wet etching is performed on the second semiconductor layer to form an optical filter.

  Finally, the first electrode, the second electrode, and the third electrode are formed to complete the wavelength variable device.

  The mesa post outer shape protective film, the membrane outer shape protective film, and the optical filter outer shape protective film can be removed with hydrofluoric acid or the like after the wavelength variable device is formed. If there is a possibility of adversely affecting the device characteristics, it may be left as it is.

  Note that wet etching may be sequentially performed on the first semiconductor layer and the second semiconductor layer, or may be performed simultaneously. Further, different materials may be used for the first semiconductor layer and the second semiconductor layer, or the same material may be used.

  As described above, also by the manufacturing method shown in FIG. 16, the optical axis-adjusted wavelength tunable device can be obtained relatively easily by repeating the photolithography process, the wet etching process, the dry etching process, and the like.

<Example>
In this example, the wavelength tunable device according to this embodiment was actually manufactured. It was manufactured by the same method as the manufacturing method according to this embodiment. A specific example when the resonance wavelength is set to 1064 nm will be described.

First, a first reflector layer composed of n-Al _0.9 Ga _0.1 As / GaAs 35 pairs was laminated on an n-GaAs (100) substrate. The film thickness of the first reflecting mirror layer was adjusted so that the resonance wavelength was 1064 nm.

  Next, on the first reflector layer, a GaInAs / GaAs-based quantum well was laminated for 3 periods (3QW) and a high Al composition layer made of an AlAs layer to form a resonator. The film thickness of the quantum well layer was 8 nm. Each quantum well layer was isolated by a GaAs barrier layer having a thickness of 20 nm.

  Next, a contact layer made of highly doped p ++ GaAs was formed on the resonator.

Next, a first semiconductor layer made of Ga _0.9 In _0.1 P _0.8 As _0.2 was formed on the contact layer. The film thickness of the first semiconductor layer was 3192 nm. The film thickness was adjusted to be 3 times the resonance wavelength of 1064 nm. Since the distance between the contact layer and the membrane is controlled by the film thickness of the first semiconductor layer (to be a support member later), the film thickness of the first semiconductor layer is a film thickness that is an integral multiple of the resonance wavelength of 1064 nm. It adjusted so that it might become. Note that Ga _0.9 In _0.1 P _0.8 As _0.2 does not cause lattice distortion with respect to the n-GaAs (100) substrate, and thus can be stacked thick.

Next, a second reflecting mirror layer made of an Al _0.9 Ga _0.1 As / GaAs 20 pair was stacked on the first semiconductor layer.

Next, a second semiconductor layer made of Ga _0.9 In _0.1 P _0.8 As _0.2 was formed on the second reflecting mirror layer. The film thickness of the second semiconductor layer was 83.1 nm.

  Next, a photoresist layer was formed on the surface of the second semiconductor layer and patterned to form a resist pattern for mesa posts. Next, dry etching was performed on the resonator, the first semiconductor layer, the second reflecting mirror layer, and the second semiconductor layer to form mesa posts. The resist pattern for mesa post was removed, the mesa post was heated at high temperature in saturated water vapor, and the AlAs layer was oxidized to form a current constriction.

  Next, a photoresist layer was patterned on the surface of the second semiconductor layer to form a resist pattern for the membrane, and dry etching was performed on a part of the mesa post to form a membrane. Next, the resist pattern for the membrane was removed, and the photoresist layer was patterned on the surface of the second semiconductor layer to form a resist pattern for the optical filter.

Next, wet etching was performed on the first semiconductor layer and the second semiconductor layer using an etchant (HCl: H ₂ O = 2: 1) to form a support member and an optical filter.

  Next, a first electrode was formed on the substrate surface on the side where the first reflecting mirror layer was not formed. A second electrode was formed on the contact layer. A third electrode was formed on the membrane.

  Thus, the wavelength tunable device manufactured by the manufacturing method according to the present embodiment was completed.

  When no potential was applied to the second electrode and the third electrode, the distance between the contact layer and the membrane was 3192 nm because it coincided with the height of the support member. At this time, the resonance wavelength of the wavelength tunable device was 1064 nm (set value).

  On the other hand, when a potential of 40.8 V is applied to the second electrode and the third electrode with a reverse polarity, the membrane moves to the support member side, and the distance between the contact layer and the membrane is 3090 nm. became. At this time, the resonant wavelength of the wavelength tunable device was 1047.2 nm, which was 17 nm shorter than the resonant wavelength when no potential was applied to the second electrode and the third electrode.

  When a potential of 16.3 V is applied to the second electrode and the third electrode with the same polarity, the membrane moves to the optical filter side, and the distance between the contact layer and the membrane is 3232. It became 8 nm. At this time, the resonance wavelength of the wavelength tunable device was 1070.8 nm, which was 6.8 nm longer than the resonance wavelength when no potential was applied to the second electrode and the third electrode.

  From this, it was confirmed that the resonance wavelength can be set by controlling the distance between the contact layer and the membrane by the potential difference between the potential applied to the second electrode and the potential applied to the third electrode. That is, it was confirmed that a wavelength tunable device that can adjust the optical axis and change the oscillation wavelength can be obtained by a relatively easy manufacturing method.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and within the scope of the gist of the embodiment of the present invention described in the claims, Various modifications and changes are possible.

100 wavelength tunable device 101 substrate 102 first reflecting mirror 103 resonator 104 contact layer 105 support member 106 second reflecting mirror 107 optical filter

JP 2007-178597 A

Claims (3)

A first reflecting mirror formed in contact with the substrate;
A resonator formed in contact with the first reflecting mirror and including a light emitting unit;
A contact layer formed in contact with the resonator;
A support member in contact with the contact layer and formed symmetrically across the optical axis of the light emitting unit;
A second reflecting mirror formed opposite to the resonator via the support member and elastically deformable;
An optical filter formed in contact with the second reflecting mirror,
A contact area between the support member and the second reflecting mirror is smaller than a contact area between the support member and the contact layer;
A wavelength tunable device in which a maximum displacement portion of the second reflecting mirror and a light transmission portion of the optical filter exist on the optical axis. The wavelength tunable device according to claim 1, wherein the optical filter and the support member are formed of an AlGaInP _x As _(1-x) (x ≠ 0) material. The optical filter is made of an Al _x1 Ga _y1 In _(1-x1-y1) P-based material, and the support member is made of an Al _x2 Ga _y2 In _(1-x2-y2) P (x1 <x2) -based material. The tunable device according to claim 1, which is formed.