Optical device

Abstract

A technical problem of the present application is to provide a novel optical device. The optical device of the present application includes: a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched by the first ferromagnetic layer and the second ferromagnetic layer; and a laser diode, at least a part of light emitted from the laser diode is irradiated to the magnetic element.

Description

Technical Field

[0001] This invention relates to optical devices. Background Technology

[0002] Lasers are used in various fields. For example, laser light is emitted from laser diodes. Laser diodes are packaged and sold. Known packages for laser diodes include CAN packages and butterfly packages.

[0003] For example, Patent Document 1 discloses a structure in which a laser diode is housed within a CAN package. Within the CAN package, a semiconductor photodiode, serving as a light detection element, is disposed on the back side of the laser diode, and the semiconductor photodiode monitors the light output from the laser diode.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2005-516404 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Semiconductor photodiodes are widely used as photoelectric conversion elements. On the other hand, further breakthroughs are sought in the development of optical devices that incorporate photoelectric conversion elements.

[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide a novel optical device.

[0010] Methods for solving problems

[0011] To address the aforementioned problem, the following methods are provided.

[0012] (1) The optical device of the first embodiment comprises: a magnetic element comprising: a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; and a laser diode, wherein at least a portion of the light emitted from the laser diode irradiates the magnetic element.

[0013] (2) In the optical device described above, the laser diode may also have a first emitting portion and a second emitting portion, wherein at least a portion of the light emitted from the first emitting portion or the second emitting portion irradiates the magnetic element.

[0014] (3) Alternatively, the optical device described above may also include a substrate, with the magnetic element and the laser diode located on or above the substrate.

[0015] (4) Alternatively, the optical device described above may also include a substrate and a support, wherein the substrate and the support are different components, the laser diode is located on or above the substrate, and the magnetic element is located on or above the support.

[0016] (5) Alternatively, the optical device described above may also include a reflector that reflects at least a portion of the light emitted from the laser diode toward the magnetic element.

[0017] (6) Alternatively, the optical device described above may irradiate at least a portion of the light from the laser diode onto the magnetic element from a direction intersecting the stacking direction of the magnetic element.

[0018] (7) Alternatively, the optical device described above may irradiate at least a portion of the light from the laser diode onto the magnetic element from the stacking direction of the magnetic element.

[0019] The effects of the invention

[0020] The optical devices described above can inspire new breakthroughs in the development of optical devices. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the package containing the optical device of the first embodiment.

[0022] Figure 2 This is a perspective view of the optical device according to the first embodiment.

[0023] Figure 3 This is a cross-sectional view of the optical device according to the first embodiment.

[0024] Figure 4 This is a perspective view of the vicinity of the magnetic element of the optical device in the first embodiment.

[0025] Figure 5 This is a cross-sectional view of the magnetic element according to the first embodiment.

[0026] Figure 6 This is a diagram illustrating the first mechanism of operation of the magnetic element in the first embodiment.

[0027] Figure 7 This is a diagram illustrating the second mechanism of operation of the magnetic element in the first embodiment.

[0028] Figure 8 This is a diagram illustrating another example of the operation of the magnetic element in the first embodiment.

[0029] Figure 9This is a diagram illustrating another example of the operation of the magnetic element in the first embodiment.

[0030] Figure 10 This is a cross-sectional view of the characteristic portion of the optical device according to the second embodiment.

[0031] Figure 11 This is a perspective view of the vicinity of the magnetic element of the optical device in the second embodiment.

[0032] Figure 12 This is a cross-sectional view of a characteristic portion of the optical device according to the third embodiment.

[0033] Figure 13 This is a perspective view of the optical device according to the fourth embodiment.

[0034] Figure 14 This is a cross-sectional view of the optical device according to the fourth embodiment.

[0035] Figure 15 This is a cross-sectional view of a characteristic portion of the optical device according to the fifth embodiment.

[0036] Figure 16 This is a cross-sectional view of a characteristic portion of the optical device according to the sixth embodiment.

[0037] Figure 17 This is a cross-sectional view of a characteristic portion of the optical device according to the seventh embodiment.

[0038] Figure 18 This is a perspective view of the vicinity of the magnetic element of the optical device in the sixth embodiment.

[0039] Explanation of reference numerals in the attached figures

[0040] 10…Substrate; 11…Buffer layer; 20…Laser diode; 21…n-type cladding; 22…Active layer; 23…p-type cladding; 24…First emission section; 25…Second emission section; 30…Magnetic element; 31…First ferromagnetic layer; 32…Second ferromagnetic layer; 33…Spacer layer; 41, 42, 51, 52, 81, 82…Electrodes; 43, 44, 83, 84…Through-hole wiring; 45, 85…First terminal; 46 86…Second terminal; 48, 61…Insulating layer; 49…Sloping portion; 60…Reflector; 70, 80…Support; 100, 101, 102, 103, 104, 105, 106…Optical components; 110…Cap; 120…Steam base; 130…Cover glass; 140…Adhesive portion; 150…Lead wire; 200…Encapsulation; L1, L2…Optical… Detailed Implementation

[0041] Hereinafter, embodiments will be described in detail with appropriate reference to the accompanying drawings. The drawings used in the following description may sometimes be enlarged to facilitate understanding of the features, and the dimensions and proportions of the constituent elements may differ from the actual figures. The materials, dimensions, etc., illustrated in the following description are merely examples, and the present invention is not limited thereto; appropriate modifications and implementations can be made within the scope of achieving the effects of the present invention.

[0042] Define the orientation. Place substrate 10 (refer to...) Figure 2 One direction within the extended plane is designated as the x-direction, and the direction within the plane orthogonal to the x-direction is designated as the y-direction. For example, the direction connecting the laser diode 20 and the magnetic element 30 is designated as the x-direction. The direction orthogonal to the substrate 10 (the direction orthogonal to both the x and y directions) is designated as the z-direction. Hereinafter, the +z direction is sometimes referred to as "up" and the -z direction as "down". Up and down are not necessarily consistent with the direction in which gravity is applied.

[0043] (First Embodiment)

[0044] Figure 1 This is a cross-sectional view of the package 200 containing the optical device 100 of the first embodiment. Figure 1 The package 200 shown is a CAN package. Package 200 is not limited to a CAN package; for example, it can also be a butterfly package.

[0045] Package 200 includes: an optics component 100, a cap 110, a stem 120, a cover glass 130, an adhesive portion 140, and leads 150. The optics component 100 is mounted on the stem 120 and surrounded by the cap 110. The cap 110 has an opening. The opening of the cap 110 is covered by the glass cover 130. The glass cover 130 is connected to the cap 110, for example, via the adhesive portion 140. The adhesive portion 140 is, for example, a low-melting-point glass. The leads 150 provide electrical connections to the outside. The leads 150 are electrically connected to the optics component 100.

[0046] Figure 2 This is a perspective view of the optical device 100 according to the first embodiment. Figure 3 This is a cross-sectional view of the optical device 100 according to the first embodiment. The optical device 100 includes a substrate 10, a laser diode 20, and a magnetic element 30. The laser diode 20 has a first emission portion 24 and a second emission portion 25, from which light L1 is emitted, and from which light L2 is emitted. At least a portion of the light L1 and L2 emitted from the laser diode 20 (at least a portion of light L2) irradiates the magnetic element 30. Light L1 is emitted to the outside, for example, through a glass cover 130.

[0047] The substrate 10 is, for example, a semiconductor substrate, a sapphire substrate, etc. The semiconductor substrate is, for example, a Si substrate, a GaN substrate, or a SiC substrate. The laser diode 20 and the magnetic element 30 are located on or above the substrate 10.

[0048] A buffer layer 11 may also be present on the upper surface of the substrate 10. The buffer layer 11 may be, for example, an n-type semiconductor. The buffer layer 11 may be, for example, an n-type GaN. The buffer layer 11 may be formed on the entire upper surface of the substrate 10, or it may be located only at the position overlapping with the laser diode 20.

[0049] The laser diode 20 has an n-type cladding 21, an active layer 22, and a p-type cladding 23. The active layer 22 is sandwiched between the n-type cladding 21 and the p-type cladding 23.

[0050] The n-type cladding 21, active layer 22, and p-type cladding 23 can each be made of known materials. The n-type cladding 21 is, for example, an n-type semiconductor. The n-type cladding 21 is, for example, a stacked film of n-type AlGaN and GaN, or n-type InP. The active layer 22 is, for example, an InGaN quantum well (MQW) layer or InGaAsP. The p-type cladding 23 is, for example, a p-type semiconductor. The p-type cladding 23 is, for example, a stacked film of p-type AlGaN and GaN, or p-type InP.

[0051] The laser diode 20 can be manufactured using known methods. For example, the laser diode 20 can be manufactured through a layer-by-layer lamination process or a fabrication process. For instance, the laser diode 20 can be formed on the substrate 10 via a vacuum film deposition process, with a buffer layer 11 or the like in between.

[0052] The laser diode 20 is held between electrodes 51 and 52. Electrode 51 is, for example, located between substrate 10 and buffer layer 11. When a voltage is applied between electrodes 51 and 52, electrons flow from n-type cladding 21 into active layer 22, and holes flow from p-type cladding 23 into active layer 22. Through the recombination of these electrons and holes within active layer 22, the laser diode 20 emits light. The light is confined within active layer 22, amplified and circulated within it, and is excited and emitted from first emission portion 24 and second emission portion 25. A portion of the light L1 emitted from first emission portion 24 is emitted to the outside. A portion of the light L2 emitted from second emission portion 25 irradiates magnetic element 30. First emission portion 24 and second emission portion 25 are the x-direction ends of active layer 22.

[0053] The magnetic element 30 and the laser diode 20 are located on the same substrate 10. The magnetic element 30 and the laser diode 20 are assembled in one article. The laser diode 20 and the magnetic element 30 are located on or above the substrate 10.

[0054] The magnetic element 30 is positioned where at least a portion (at least a portion of light L2) of the light L1 and L2 emitted from the laser diode 20 is irradiated. The height position of the magnetic element 30 in the z-direction coincides, for example, with the height position of the second emitting section 25 in the z-direction. The magnetic element 30 is, for example, positioned in front of the second emitting section 25 of the laser diode 20 (in front of the travel direction of the light L2 emitted from the second emitting section 25). At least a portion (at least a portion of light L2) of the light L1 and L2 emitted from the laser diode 20 travels from the stacking direction of the magnetic element 30 (in... Figure 2 The direction of the intersection (Z direction) is directed towards the magnetic element 30.

[0055] The light L2 illuminating the magnetic element 30 is not limited to visible light; it can also be infrared light with a wavelength longer than visible light, or ultraviolet light with a wavelength shorter than visible light. For example, the wavelength of visible light is 380 nm or more and less than 800 nm. The wavelength of infrared light is, for example, 800 nm or more and less than 1 mm. The wavelength of ultraviolet light is, for example, 200 nm or more and less than 380 nm. The light L2 illuminating the magnetic element 30 is, for example, light containing a high-frequency optical signal and exhibiting intensity variations. A high-frequency optical signal is, for example, a signal with a frequency of 100 MHz or more.

[0056] Figure 4 This is a perspective view of the vicinity of the magnetic element 30 in the optical device 100 of the first embodiment. The magnetic element 30 is electrically connected, for example, to electrodes 41, 42; through-hole wiring 43, 44; a first terminal 45; and a second terminal 46. The magnetic element 30 is surrounded by an insulating layer 48.

[0057] Electrode 41 is connected to the first surface of magnetic element 30. Electrode 42 is connected to the second surface of magnetic element 30. The first surface and the second surface are opposite to each other in the stacking direction of magnetic element 30.

[0058] Electrodes 41 and 42 comprise a conductive material. Electrodes 41 and 42 are made of metals such as Cu, Al, Au, or Ru. Ta or Ti may also be stacked on top of these metals. Furthermore, Cu-Ta laminates, Ta-Cu-Ti laminates, and Ta-Cu-TaN laminates can also be used as electrodes 41 and 42. Additionally, TiN and TaN can also be used as electrodes 41 and 42.

[0059] Electrodes 41 and 42 may also be translucent relative to the wavelength of light irradiating the magnetic element 30. For example, electrodes 41 and 42 may be transparent electrodes comprising transparent electrode materials containing oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium gallium zinc oxide (IGZO). Furthermore, electrodes 41 and 42 may also be configured to have a structure containing multiple columnar metals within these transparent electrode materials.

[0060] Through-hole wiring 43 connects the first terminal 45 to electrode 41 or electrode 42. There are, for example, two first terminals 45. Current or voltage is input to one of the first terminals 45, and the other first terminal 45 is connected to a reference potential. The first terminals 45 are, for example, exposed on the upper surface of the insulating layer 48.

[0061] Through-hole wiring 44 connects the second terminal 46 to electrode 41 or electrode 42. There are, for example, two second terminals 46. A signal is output from one of the second terminals 46, and the other second terminal 46 is connected to a reference potential. The second terminals 46 are, for example, exposed on the upper surface of the insulating layer 48.

[0062] The through-hole wirings 43, 44, the first terminal 45, and the second terminal 46 contain a conductive material. The same material as that exemplified as the electrodes 41 and 42 can be used as the material for the through-hole wirings 43, 44, the first terminal 45, and the second terminal 46.

[0063] Insulating layer 48 is an interlayer insulating layer. Insulating layer 48 is, for example, an oxide, nitride, or oxynitride of Si, Al, or Mg. Insulating layer 48 is, for example, silicon oxide (SiO₂). x ), silicon nitride (SiN) x Silicon carbide (SiC), chromium nitride, silicon carbide nitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO2) x )wait.

[0064] When the state of the light L2 illuminating the magnetic element 30 changes, the voltage output from the magnetic element 30 (the potential difference between electrodes 41 and 42) changes according to the change in the state of the light L2.

[0065] Figure 5 This is a cross-sectional view of the magnetic element 30 according to the first embodiment. The magnetic element 30, for example, has: a first ferromagnetic layer 31, a second ferromagnetic layer 32, and a spacer layer 33. The first ferromagnetic layer 31 is connected to the electrode 41, and the second ferromagnetic layer 32 is connected to the electrode 42. The spacer layer 33 is located between the first ferromagnetic layer 31 and the second ferromagnetic layer 32. The magnetic element 30 may also have other layers besides these. For example, light L2 from the x-direction is irradiated onto the magnetic element 30.

[0066] The magnetic element 30 is, for example, an MTJ (Magnetic Tunnel Junction) element in which the spacer layer 33 is made of insulating material. In this case, the magnetic element 30 is an element whose resistance value in the stacking direction (resistance value when current flows along the stacking direction) changes according to the relative change in the magnetization state of the first ferromagnetic layer 31 and the magnetization state of the second ferromagnetic layer 32. Such an element is also called a magnetoresistive element.

[0067] The first ferromagnetic layer 31 is a light-detecting layer that detects changes in magnetization state when illuminated by external light. The first ferromagnetic layer 31 is also referred to as a magnetization-free layer. A magnetization-free layer is a layer of magnetic material whose magnetization state changes when energy from a specified external source is applied. This specified external energy can be, for example, externally illuminated light, current flowing along the stacking direction of the magnetic element 30, or an external magnetic field. The magnetization of the first ferromagnetic layer 31 changes according to the intensity of the light L2 illuminating it.

[0068] The first ferromagnetic layer 31 comprises ferromagnetic materials. In this specification, ferromagnetism includes ferrimagnetism. The first ferromagnetic layer 31 may, for example, contain at least any magnetic element selected from magnetic elements such as Co, Fe, or Ni. The first ferromagnetic layer 31 may also contain magnetic elements as described above and non-magnetic elements such as B, Mg, Hf, and Gd. The first ferromagnetic layer 31 may, for example, be an alloy containing both magnetic and non-magnetic elements. The first ferromagnetic layer 31 may also consist of multiple layers. For example, the first ferromagnetic layer 31 may be a CoFeB alloy, a laminate containing a CoFeB alloy layer sandwiched by an Fe layer, or a laminate containing a CoFeB alloy layer sandwiched by a CoFe layer.

[0069] The first ferromagnetic layer 31 can be an in-plane magnetized film with an easy magnetization axis in the in-plane direction, or a vertical magnetized film with an easy magnetization axis in the direction perpendicular to the film surface (the stacking direction of the magnetic element 30).

[0070] The thickness of the first ferromagnetic layer 31 is, for example, 1 nm or more and 5 nm or less. The thickness of the first ferromagnetic layer 31 is preferably, for example, 1 nm or more and 2 nm or less. When the first ferromagnetic layer 31 is a vertically magnetized film, if the thickness of the first ferromagnetic layer 31 is thin, the effect of applying vertical magnetic anisotropy from the layers above and below the first ferromagnetic layer 31 is enhanced, and the vertical magnetic anisotropy of the first ferromagnetic layer 31 is increased. That is, if the vertical magnetic anisotropy of the first ferromagnetic layer 31 is high, the force required for magnetization to return to the direction perpendicular to the film surface is enhanced. On the other hand, if the thickness of the first ferromagnetic layer 31 is thick, the effect of applying vertical magnetic anisotropy from the layers above and below the first ferromagnetic layer 31 is relatively weak, and the vertical magnetic anisotropy of the first ferromagnetic layer 31 is weakened.

[0071] When the thickness of the first ferromagnetic layer 31 decreases, its volume as a ferromagnetic material decreases; conversely, when it increases, its volume as a ferromagnetic material increases. The reactivity of the first ferromagnetic layer 31 in magnetization when external energy is applied is inversely proportional to the product of its magnetic anisotropy (Ku) and volume (V) (KuV). That is, when the product of the magnetic anisotropy and volume of the first ferromagnetic layer 31 decreases, its reactivity to light is high. From this perspective, to improve the reactivity to light, it is preferable to reduce the volume of the first ferromagnetic layer 31 while appropriately designing its magnetic anisotropy.

[0072] When the thickness of the first ferromagnetic layer 31 is greater than 2 nm, for example, an intercalation layer composed of Mo or W can be provided within the first ferromagnetic layer 31. That is, a stack of a ferromagnetic layer, an intercalation layer, and a ferromagnetic layer stacked sequentially can also be used as the first ferromagnetic layer 31. Through the interfacial magnetic anisotropy at the interface between the intercalation layer and the ferromagnetic layer, the overall perpendicular magnetic anisotropy of the first ferromagnetic layer 31 is improved. The thickness of the intercalation layer is, for example, 0.1 nm to 0.6 nm.

[0073] The second ferromagnetic layer 32 is a magnetization-fixed layer. A magnetization-fixed layer is a layer composed of a magnetic material whose magnetization state is less likely to change compared to a magnetization-free layer when magnetized by applied energy from a predetermined external source. For example, the direction of magnetization in the magnetization-fixed layer is less likely to change compared to a magnetization-free layer when magnetized by applied energy from a predetermined external source. Furthermore, for example, the magnitude of magnetization in the magnetization-fixed layer is less likely to change compared to a magnetization-free layer when magnetized by applied energy from a predetermined external source. For example, the coercivity of the second ferromagnetic layer 32 is greater than that of the first ferromagnetic layer 31. For example, the second ferromagnetic layer 32 has an easy magnetization axis in the same direction as the first ferromagnetic layer 31. The second ferromagnetic layer 32 can also be an in-plane magnetization film or a perpendicular magnetization film.

[0074] The material constituting the second ferromagnetic layer 32 is, for example, the same as that of the first ferromagnetic layer 31. The second ferromagnetic layer 32 may also be, for example, a laminate consisting of Co with a thickness of 0.4 nm or more and 1.0 nm or less, Mo with a thickness of 0.1 nm or more and 0.5 nm or less, a CoFeB alloy with a thickness of 0.3 nm or more and 1.0 nm or less, and Fe with a thickness of 0.3 nm or more and 1.0 nm or less, stacked sequentially.

[0075] The magnetization of the second ferromagnetic layer 32 can also be fixed, for example, by magnetic coupling with the third ferromagnetic layer via a magnetic coupling layer. In this case, the layer combining the second ferromagnetic layer 32, the magnetic coupling layer, and the third ferromagnetic layer is sometimes referred to as a magnetization fixing layer.

[0076] The third ferromagnetic layer is magnetically coupled to the second ferromagnetic layer 32, for example. The magnetic coupling is, for example, antiferromagnetic coupling, generated through RKKY interactions. The material constituting the third ferromagnetic layer is, for example, the same as the first ferromagnetic layer 31. The magnetic coupling layer is, for example, Ru, Ir, etc.

[0077] The spacer layer 33 is a non-magnetic layer disposed between the first ferromagnetic layer 31 and the second ferromagnetic layer 32. The spacer layer 33 is formed by a layer made of a conductor, an insulator, or a semiconductor, or by a layer containing current-carrying points made of conductors in an insulator. The thickness of the spacer layer 33 can be adjusted according to the orientation of the magnetization of the first ferromagnetic layer 31 and the second ferromagnetic layer 32 in the initial state, as described later.

[0078] For example, when the spacer layer 33 is made of an insulator, the magnetic element 30 has a magnetic tunnel junction (MTJ) composed of a first ferromagnetic layer 31, a spacer layer 33, and a second ferromagnetic layer 32. Such an element is called an MTJ element. In this case, the magnetic element 30 can exhibit a tunnel magnetoresistance (TMR) effect. For example, when the spacer layer 33 is made of metal, the magnetic element 30 can exhibit a giant magnetoresistance (GMR) effect. Such an element is called a GMR element. Depending on the material of the spacer layer 33, the magnetic element 30 may be called an MTJ element, a GMR element, etc., but they are all generally referred to as magnetoresistance effect elements.

[0079] When the spacer layer 33 is made of an insulating material, materials containing aluminum oxide, magnesium oxide, titanium oxide, or silicon oxide can be used as the spacer layer 33. Furthermore, these insulating materials can also contain elements such as Al, B, Si, and Mg, or magnetic elements such as Co, Fe, and Ni. By adjusting the thickness of the spacer layer 33 to exhibit a high TMR effect between the first ferromagnetic layer 31 and the second ferromagnetic layer 32, a high magnetoresistivity change rate can be obtained. To efficiently utilize the TMR effect, the thickness of the spacer layer 33 can be 0.5 nm or more and 5.0 nm or less, or 1.0 nm or more and 2.5 nm or less.

[0080] When the spacer layer 33 is made of a non-magnetic conductive material, conductive materials such as Cu, Ag, Au, or Ru can be used. In order to efficiently utilize the GMR effect, the film thickness of the spacer layer 33 can be 0.5 nm or more and 5.0 nm or less, or 2.0 nm or more and 3.0 nm or less.

[0081] When the spacer layer 33 is made of a non-magnetic semiconductor material, materials such as zinc oxide, indium oxide, tin oxide, germanium oxide, gallium oxide, or ITO can be used. In this case, the film thickness of the spacer layer 33 can also be 1.0 nm or more and 4.0 nm or less.

[0082] When the spacer layer 33 is used as the layer containing the current-carrying point formed by the conductor in the non-magnetic insulator, it can also be configured as follows: a structure containing the current-carrying point formed by the non-magnetic conductor such as Cu, Au, or Al in a non-magnetic insulator made of aluminum oxide or magnesium oxide. Alternatively, the conductor can be made of magnetic elements such as Co, Fe, or Ni. In this case, the film thickness of the spacer layer 33 can be 1.0 nm or more and 2.5 nm or less. The current-carrying point is, for example, a columnar shape with a diameter of 1 nm or more and 5 nm or less when viewed from a direction perpendicular to the film surface.

[0083] In addition to the magnetic element 30, it may also have: a base layer, a cap layer, and a vertical magnetization induction layer. The base layer is located below the second ferromagnetic layer 32. The base layer is a seed layer or a buffer layer. The seed layer improves the crystallinity of the layers stacked on it. Examples of seed layers are Pt, Ru, Hf, Zr, and NiFeCr. The thickness of the seed layer is, for example, 1 nm or more and 5 nm or less. The buffer layer is a layer that mitigates lattice mismatch between different crystals. Examples of buffer layers are Ta, Ti, W, Zr, Hf, or nitrides of these elements. The thickness of the buffer layer is, for example, 1 nm or more and 5 nm or less.

[0084] The capping layer is located above the first ferromagnetic layer 31. During the process, the capping layer prevents damage to the underlying layer and improves the crystallinity of the underlying layer during annealing. The thickness of the capping layer is, for example, less than 3 nm. Examples of capping layers include MgO, W, Mo, Ru, Ta, Cu, Cr, or laminates thereof.

[0085] A vertical magnetization induction layer is formed when the first ferromagnetic layer 31 is a vertical magnetization film. The vertical magnetization induction layer is stacked on the first ferromagnetic layer 31. The vertical magnetization induction layer senses the vertical magnetic anisotropy of the first ferromagnetic layer 31. The vertical magnetization induction layer is, for example, magnesium oxide, W, Ta, Mo, etc. When the vertical magnetization induction layer is magnesium oxide, it is preferable that the magnesium oxide is oxygen-deficient to improve conductivity. The film thickness of the vertical magnetization induction layer is, for example, 0.5 nm or more and 2.0 nm or less.

[0086] The magnetic element 30 is fabricated, for example, through a layer stacking process, an annealing process, and a processing process. Each layer is formed, for example, by sputtering. Annealing is performed, for example, at a temperature above 250°C and below 450°C. The processing of the stacked film is performed, for example, using photolithography and etching. The stacked film forms a columnar magnetic element 30. The magnetic element 30 can also be cylindrical or prismatic. For example, the shortest width of the magnetic element 30 when viewed from the stacking direction can be 10 nm or more and 2000 nm or less, or 30 nm or more and 500 nm or less. Through the above processes, the magnetic element 30 can be obtained.

[0087] The magnetic element 30 can be fabricated independently of the material constituting the substrate. Therefore, the magnetic element 30 can be fabricated directly on the substrate 10 without the use of an adhesive layer or the like. For example, the magnetic element 30 can be formed on the substrate 10 by a vacuum film deposition process with an insulating layer 48 or the like in between.

[0088] Next, several examples of the operation of the magnetic element 30 will be explained. Light L2 is irradiated onto the first ferromagnetic layer 31. The magnetic element 30 detects changes in the intensity of light L2. The output voltage from the magnetic element 30 changes according to the change in the intensity of light L2 irradiating the first ferromagnetic layer 31. The exact mechanism by which the output voltage from the magnetic element 30 changes according to light irradiation is not yet fully understood; for example, consider the following two mechanisms.

[0089] Figure 6 This is a diagram illustrating the first mechanism of operation of the magnetic element 30 in the first embodiment. Figure 6 In the graph above, the vertical axis represents the intensity of light L2 illuminating the first ferromagnetic layer 31, and the horizontal axis represents time. Figure 6 In the graph below, the vertical axis represents the resistance value in the stacking direction of the magnetic element 30, and the horizontal axis represents time.

[0090] First, in the state where the first ferromagnetic layer 31 is irradiated with light of the first intensity (hereinafter referred to as the initial state), the magnetization M31 of the first ferromagnetic layer 31 and the magnetization M32 of the second ferromagnetic layer 32 are parallel. The resistance value in the stacking direction of the magnetic element 30 represents the first resistance value R1, and the magnitude of the output voltage from the magnetic element 30 represents the first value. The first intensity can also be the case where the intensity of the light irradiating the first ferromagnetic layer 31 is zero.

[0091] The resistance value of the magnetic element 30 along its stacking direction is, for example, such that when a sensed current Is flows along the stacking direction of the magnetic element 30, a voltage is generated across the magnetic element 30, and this voltage value is determined using Ohm's law. The output voltage from the magnetic element 30 is generated between electrodes 41 and 42. Figure 6In the example shown, it is preferable to allow the sensing current Is to flow from the first ferromagnetic layer 31 toward the second ferromagnetic layer 32. By allowing the sensing current Is to flow in this direction, a spin-transfer torque is applied to the magnetization M31 of the first ferromagnetic layer 31 in the same direction as the magnetization M32 of the second ferromagnetic layer 32. Initially, the magnetization M31 and magnetization M32 are parallel. Furthermore, by allowing the sensing current Is to flow in this direction, it is possible to prevent the magnetization M31 of the first ferromagnetic layer 31 from reversing during operation.

[0092] Next, the intensity of the light L2 illuminating the first ferromagnetic layer 31 changes. Through the external energy generated by the irradiation of light L2, the magnetization M31 of the first ferromagnetic layer 31 tilts from its initial state. The angle between the direction of the magnetization M31 of the first ferromagnetic layer 31 in the state without light irradiation and the direction of the magnetization M31 in the state with light irradiation is both greater than 0° and less than 90°.

[0093] When the magnetization M31 of the first ferromagnetic layer 31 tilts from its initial state, the resistance value in the stacking direction of the magnetic element 30 changes. Furthermore, the output voltage from the magnetic element 30 changes. For example, the greater the intensity of the light L2 illuminating the magnetic element 30, the greater the tilt of the magnetization M31 relative to its initial state. For example, depending on the tilt of the magnetization M31 of the first ferromagnetic layer 31, the resistance value in the stacking direction of the magnetic element 30 becomes a second resistance value R2, a third resistance value R3, and a fourth resistance value R4. The resistance value increases in the order of first resistance value R1, second resistance value R2, third resistance value R3, and fourth resistance value R4. That is, depending on the tilt of the magnetization M31 of the first ferromagnetic layer 31, the output voltage from the magnetic element 30 changes from a first voltage value to a second, third, and fourth voltage value. The output voltage increases in the order of first, second, third, and fourth voltage values.

[0094] When the intensity of the light L2 incident on the magnetic element 30 changes, the output voltage (resistance value in the stacking direction of the magnetic element 30) from the magnetic element 30 changes accordingly. The output voltage from the magnetic element 30 changes in a direct correspondence with the change in the intensity of the light L2 incident on the first ferromagnetic layer 31. In other words, the magnetic element 30 can convert the change in the intensity of the incident light L2 into a change in the output voltage. That is, the magnetic element 30 can convert the received light into an electrical signal. Here, four values ​​are shown as an example, but the number of values ​​read can be freely designed by setting the threshold of the output voltage from the magnetic element 30. Furthermore, the magnetic element 30 can also output analog values ​​as is.

[0095] The magnetization M31 of the first ferromagnetic layer 31 has a spin-transfer torque in the same direction as the magnetization M32 of the second ferromagnetic layer 32. Therefore, when the intensity of the light L2 illuminating the first ferromagnetic layer 31 returns to the first intensity, the magnetization M31, which was tilted from the initial state, returns to the initial state. When the magnetization M31 returns to the initial state, the resistance value in the stacking direction of the magnetic element 30 returns to the first resistance value R1.

[0096] The example described here is the case where magnetization M31 and magnetization M32 are parallel in the initial state. It is also possible that magnetization M31 and magnetization M32 are antiparallel in the initial state. In this case, the more inclined magnetization M31 is (the greater the change in angle of magnetization M31 from the initial state), the smaller the resistance value in the stacking direction of the magnetic element 30. When the initial state is that magnetization M31 and magnetization M32 are antiparallel, it is preferable that the sensing current Is flows from the second ferromagnetic layer 32 toward the first ferromagnetic layer 31. By causing the sensing current Is to flow in this direction, a spin-transfer torque is applied to magnetization M31 of the first ferromagnetic layer 31 in the opposite direction to magnetization M32 of the second ferromagnetic layer 32, so that magnetization M31 and magnetization M32 are antiparallel in the initial state.

[0097] Figure 7 This is a diagram illustrating the second mechanism of operation of the magnetic element 30 in the first embodiment. Figure 7 In the graph above, the vertical axis represents the intensity of light L2 illuminating the first ferromagnetic layer 31, and the horizontal axis represents time. Figure 7 In the graph below, the vertical axis represents the resistance value in the stacking direction of the magnetic element 30, and the horizontal axis represents time.

[0098] Figure 7 The initial state shown is the same as Figure 6 The initial states shown are the same. Figure 7 In the example shown, it is also preferable to allow the sensing current Is to flow from the first ferromagnetic layer 31 toward the second ferromagnetic layer 32. By allowing the sensing current Is to flow in this direction, a spin-transfer torque is applied to the magnetization M31 of the first ferromagnetic layer 31 in the same direction as the magnetization M32 of the second ferromagnetic layer 32, thus maintaining the initial state.

[0099] Next, the intensity of the light L2 illuminating the first ferromagnetic layer 31 changes. Through the external energy generated by the irradiation of light L2, the magnetization M31 of the first ferromagnetic layer 31 decreases from its initial state. As the magnetization M31 of the first ferromagnetic layer 31 decreases from its initial state, the resistance value in the stacking direction of the magnetic element 30 changes. Furthermore, the output voltage from the magnetic element 30 changes. For example, the greater the intensity of the light L2 illuminating the magnetic element 30, the smaller the magnetization M31. For example, depending on the magnitude of the magnetization M31 of the first ferromagnetic layer 31, the resistance value in the stacking direction of the magnetic element 30 becomes a second resistance value R2, a third resistance value R3, and a fourth resistance value R4. The resistance value increases in the order of the first resistance value R1, the second resistance value R2, the third resistance value R3, and the fourth resistance value R4. That is, depending on the magnitude of the magnetization M31 of the first ferromagnetic layer 31, the output voltage from the magnetic element 30 changes from a first voltage value to a second voltage value, a third voltage value, and a fourth voltage value. The output voltage increases in the order of the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value.

[0100] When the intensity of light illuminating the first ferromagnetic layer 31 returns to the first intensity, the magnetization M31 of the first ferromagnetic layer 31 is restored, and the magnetic element 30 returns to its initial state. That is, the resistance value of the magnetic element 30 in the stacking direction returns to the first resistance value R1.

[0101] exist Figure 7 Alternatively, in the initial state, magnetization M31 and magnetization M32 can be antiparallel. In this case, the smaller the size of magnetization M31, the smaller the resistance value in the stacking direction of the magnetic element 30. When magnetization M31 and magnetization M32 are antiparallel as the initial state, it is preferable that the sensing current Is flows from the second ferromagnetic layer 32 toward the first ferromagnetic layer 31.

[0102] In addition, Figure 6 and Figure 7 The example illustrates the cases where magnetization M31 and magnetization M32 are parallel or antiparallel in the initial state. Magnetization M31 and magnetization M32 can also be orthogonal in the initial state. For example, the first ferromagnetic layer 31 is an in-plane magnetized film with magnetization M31 oriented in the in-plane direction, and the second ferromagnetic layer 32 is a perpendicularly magnetized film with magnetization M32 oriented perpendicular to the film surface, which conforms to this case. Due to magnetic anisotropy, magnetization M31 can be oriented in any direction within the film surface, and magnetization M32 can be oriented perpendicular to the film surface, thus making magnetization M31 and magnetization M32 orthogonal in the initial state.

[0103] Figure 8 and Figure 9 This is another example of the operation of the first mechanism of the magnetic element 30 in the first embodiment. Figure 8 and Figure 9 In the process, the direction of the sensing current Is applied to the magnetic element 30 is different. Figure 8 The sensing current Is flows from the first ferromagnetic layer 31 toward the second ferromagnetic layer 32. Figure 9 The sensing current Is flows from the second ferromagnetic layer 32 toward the first ferromagnetic layer 31.

[0104] exist Figure 8 and Figure 9 In any case, the magnetization M31 is subjected to a spin-transfer torque in the initial state by sensing the current Is flowing through the magnetic element 30. Figure 8 In this case, the magnetization M31 becomes parallel to the magnetization M32 of the second ferromagnetic layer 32, resulting in a spin-transfer torque. Figure 9 In this case, the magnetization M31 becomes antiparallel to the magnetization M32 of the second ferromagnetic layer 32, resulting in a spin-transfer torque. Figure 8 and Figure 9 In any case, in the initial state, the effect of magnetic anisotropy on magnetization M31 is greater than the effect of spin-transfer torque. Therefore, magnetization M31 is oriented in any direction within the film surface.

[0105] When the intensity of light L2 illuminating the first ferromagnetic layer 31 increases, the magnetization M31 of the first ferromagnetic layer 31 tilts from its initial state due to the external energy generated by the irradiation of light L2. This is because the sum of the effect of light L2 irradiation and the effect of spin-transfer torque applied to the magnetization M31 is greater than the effect of the magnetic anisotropy of the magnetization M31. When the intensity of light L2 illuminating the first ferromagnetic layer 31 increases, Figure 8 In this case, the magnetization M31 tilts in a manner that makes it parallel to the magnetization M32 of the second ferromagnetic layer 32. Figure 9 In this case, the magnetization M31 tilts in a manner that is antiparallel to the magnetization M32 of the second ferromagnetic layer 32. Due to the different directions of the spin-transfer torque acting on the magnetization M31, Figure 8 and Figure 9 The tilt direction of the magnetized M31 is different.

[0106] When the intensity of the light illuminating the first ferromagnetic layer 31 increases, in Figure 8 In this case, the resistance value in the stacking direction of the magnetic element 30 decreases, and in Figure 9 In this case, the resistance value in the stacking direction of the magnetic element 30 increases. That is, when the intensity of light illuminating the first ferromagnetic layer 31 increases, the resistance value increases. Figure 8 In this case, the output voltage from magnetic element 30 decreases, Figure 9 In this case, the output voltage of magnetic element 30 increases.

[0107] When the intensity of light L2 illuminating the first ferromagnetic layer 31 returns to the first intensity, the magnetization state of the first ferromagnetic layer 31 is restored according to the effect of magnetic anisotropy on the magnetization M31. As a result, the magnetic element 30 returns to its initial state.

[0108] Here, an example is given where the first ferromagnetic layer 31 is an in-plane magnetized film and the second ferromagnetic layer 32 is a perpendicularly magnetized film, but this relationship can also be reversed. That is, in the initial state, magnetization M31 is oriented perpendicular to the film surface, and magnetization M32 is oriented in any direction within the film surface.

[0109] As described above, the magnetic element 30 receives light L2 and converts the received light L2 into an electrical signal. By converting light L2 into an electrical signal by the magnetic element 30, the intensity change of a portion (light L2) of the light L1 and L2 emitted from the laser diode 20 can be monitored via the magnetic element 30.

[0110] The intensity change of light L1 emitted from the first emission section 24 of the laser diode 20 corresponds to the intensity change of light L2 emitted from the second emission section 25. By monitoring the intensity change of light L2 by the magnetic element 30, the intensity change of light L1 emitted to the outside can be monitored.

[0111] Furthermore, the smaller the volume of the first ferromagnetic layer 31, the easier it is for the magnetization M31 of the first ferromagnetic layer 31 to change with the irradiation of light L2. In other words, the smaller the volume of the first ferromagnetic layer 31, the easier it is for the magnetization M31 of the first ferromagnetic layer 31 to change its state according to the irradiation of light L2. In other words, when the volume of the first ferromagnetic layer 31 is reduced, even a small amount of light can cause a change in the magnetization M31. That is, the magnetic element 30 of the first embodiment can detect light with high sensitivity.

[0112] More precisely, the ease with which the magnetization M31 changes depends on the magnitude of the product (KuV) of the magnetic anisotropy (Ku) and volume (V) of the first ferromagnetic layer 31. A smaller KuV means that even a tiny amount of light will cause the magnetization M31 to change; a larger KuV means that the magnetization M31 will not change unless the light intensity is significantly greater. That is, the KuV of the first ferromagnetic layer 31 is designed based on the amount of laser light determined by the application. Assuming the detection of extremely small amounts of light, these tiny amounts of light can be detected by reducing the KuV of the first ferromagnetic layer 31. Since reducing the device size in existing pn junction semiconductors is difficult, the detection of such tiny amounts of light is a significant advantage. The KuV can be reduced by decreasing the volume of the first ferromagnetic layer 31.

[0113] Furthermore, the magnetic element 30 can be fabricated independently of the substrate material. Therefore, it can be fabricated on the same substrate as the substrate 10 supporting the laser diode 20. The magnetic element 30 can be formed together with the laser diode 20 using a process on the substrate 10. For example, the laser diode 20 and the magnetic element 30 can be formed on the same substrate 10 using a vacuum deposition process. By treating the laser diode 20 and the magnetic element 30 as a single component formed on the same substrate, the number of components is reduced compared to the case where laser diodes and semiconductor photodiodes need to be treated as separate components.

[0114] (Second Implementation)

[0115] Figure 10 This is a cross-sectional view of the characteristic portion of the optical device 101 according to the second embodiment. Figure 11 This is a perspective view of the vicinity of the magnetic element 30 of the optical device 101 in the second embodiment. In the second embodiment, the same structures as in the first embodiment are labeled with the same reference numerals, and descriptions are omitted.

[0116] Optical device 101 includes a reflector 60. The reflector 60 reflects at least a portion (at least a portion of light L2) emitted from laser diode 20 toward magnetic element 30. The reflector 60 is positioned in the direction of travel of light L2 from the second emitting portion 25 of laser diode 20. The height position of the reflector 60 in the z-direction is, for example, the same as the height position of the second emitting portion 25 of laser diode 20 in the z-direction. The reflector 60 has an inclined surface that is tilted relative to the direction of travel of light L2.

[0117] Reflector 60 reflects light. Reflector 60 is, for example, a mirror. Reflector 60 is surrounded by an insulating layer 61. The same material as insulating layer 48 can be used for insulating layer 61.

[0118] The magnetic element 30 is located within the insulating layer 48 on the insulating layer 61. The magnetic element 30 is positioned above the substrate 10. The height position of the magnetic element 30 (first ferromagnetic layer 31) in the z-direction is different from that of the second emission portion 25. The magnetic element 30 is, for example, positioned above the reflector 60.

[0119] Light L2 reflected by reflector 60 illuminates magnetic element 30 from, for example, the stacking direction of magnetic element 30. In this case, electrode 42 is transmissive relative to the wavelength of light L2 illuminating magnetic element 30. A portion of light L2 is transmitted through electrode 42, and light illuminates magnetic element 30. An example is shown here where electrode 42 is positioned closer to reflector 60 than electrode 41; electrode 41 can also be positioned closer to reflector 60 than electrode 42 (the first ferromagnetic layer 31 can also be positioned closer to reflector 60 than the second ferromagnetic layer 32). In this case, electrode 41 is transmissive relative to the wavelength of light illuminating magnetic element 30. A portion of light L2 is transmitted through electrode 41, and light illuminates magnetic element 30. When electrode 41 is positioned closer to reflector 60 than electrode 42, the illumination efficiency of light L2 onto the first ferromagnetic layer 31 is improved.

[0120] The optical device 101 of the second embodiment has the same effect as the optical device 100 of the first embodiment. Furthermore, the direction of light L2 irradiation onto the magnetic element 30 can be freely designed using the reflector 60. For example, when light L2 is irradiated onto the magnetic element 30 from the stacking direction, a wide light-receiving area of ​​the magnetic element 30 can be ensured.

[0121] (Third Implementation)

[0122] Figure 12 This is a cross-sectional view of the characteristic portion of the optical device 102 according to the third embodiment. In the third embodiment, the same structures as in the first embodiment are labeled with the same reference numerals, and descriptions are omitted.

[0123] In the optical device 102 of the third embodiment, the stacking direction of the magnetic element 30 is tilted relative to the z-direction. Light L2 emitted from the second emission portion 25 of the laser diode 20 irradiates the side surface of the magnetic element 30 and the first surface of the magnetic element 30 on the electrode 41 side.

[0124] The optical device 102 of the third embodiment can achieve the same effect as the optical device 100 of the first embodiment.

[0125] (Fourth implementation)

[0126] Figure 13 This is a perspective view of the optical device 103 according to the fourth embodiment. Figure 14 This is a cross-sectional view of the optical device 103 according to the fourth embodiment. In the fourth embodiment, the same reference numerals are used for structures that are the same as those in the first embodiment, and descriptions are omitted.

[0127] The optical device 103 includes a substrate 10 supporting a laser diode 20 and a support 70 supporting a magnetic element 30. The support 70 is a component different from the substrate 10 on which the laser diode 20 is formed. The support 70 and the substrate 10 may, for example, be as follows: Figure 13 and Figure 14 As shown, the laser diode 20 is fixed to a common support member 90. The laser diode 20 is located on or above the substrate 10. The magnetic element 30 is located on or above the support body 70. In the first to third embodiments, examples are shown where the laser diode 20 and the magnetic element 30 are formed on or above the same substrate 10. In the fourth embodiment, the laser diode 20 and the magnetic element 30 are formed on different members.

[0128] The support 70 is, for example, made of the same material as the substrate 10. The magnetic element 30 is located within the insulating layer 48 on the support 70.

[0129] The height position of the magnetic element 30 in the z-direction is, for example, consistent with the height position of the second emitting portion 25 of the laser diode 20 in the z-direction. At least a portion of the light emitted from the laser diode 20 (at least a portion of light L2) irradiates the magnetic element 30 from a direction intersecting the stacking direction (z-direction) of the magnetic element 30.

[0130] Even when the laser diode 20 and the magnetic element 30 are formed on different components, the optical device 103 can use the magnetic element 30 to monitor the intensity change of at least a portion (at least a portion of L2) of the light emitted from the laser diode 20. That is, the optical device 103 can monitor the intensity change of the light L1 emitted from the laser diode 20 to the outside.

[0131] (Fifth Embodiment)

[0132] Figure 15 This is a cross-sectional view of the characteristic portion of the optical device 104 according to the fifth embodiment. In the fifth embodiment, the same structures as in the above-described embodiments are labeled with the same reference numerals, and descriptions are omitted.

[0133] In the optical device 104, the substrate 10 supporting the laser diode 20 and the support 70 supporting the magnetic element 30 are different components. The laser diode 20 is located on or above the substrate 10. The magnetic element 30 is located on or above the support 70. The magnetic element 30 is located within the insulating layer 48 on the support 70.

[0134] Between the support 70 and the magnetic element 30, there is a reflector 60 covered by an insulating layer 61. The height position of the reflector 60 in the z-direction is, for example, consistent with the height position of the second emission portion 25 of the laser diode 20 in the z-direction.

[0135] Reflector 60 reflects at least a portion of the light emitted from laser diode 20 (at least a portion of light L2) toward magnetic element 30. The light L2 reflected by reflector 60 illuminates magnetic element 30, for example, from the stacking direction of magnetic element 30. In this case, electrode 42 is transmissive relative to the wavelength of light L2 illuminating magnetic element 30. A portion of light L2 passes through electrode 42, illuminating magnetic element 30.

[0136] The optical device 104 of the fifth embodiment is an optical device that combines the structural features of the optical device 101 of the second embodiment with the structural features of the optical device 103 of the fourth embodiment. Therefore, the optical device 104 of the fifth embodiment has the same effects as these optical devices 101 and 103.

[0137] (Sixth Embodiment)

[0138] Figure 16 This is a cross-sectional view of the characteristic portion of the optical device 105 according to the sixth embodiment. In the sixth embodiment, the same structures as in the above-described embodiments are labeled with the same reference numerals, and descriptions are omitted.

[0139] In the optical device 105, the substrate 10 supporting the laser diode 20 and the support 70 supporting the magnetic element 30 are different components. The laser diode 20 is located above or on the substrate 10. The magnetic element 30 is located above or on the support 70. The stacking direction of the magnetic element 30 is inclined relative to the z-direction. The height position of the magnetic element 30 in the z-direction is, for example, consistent with the height position of the second emission portion 25 of the laser diode 20 in the z-direction.

[0140] Light L2 emitted from the second emission section 25 of the laser diode 20 irradiates the side surface of the magnetic element 30 and the first surface of the magnetic element 30 on the electrode 41 side. In this case, the electrode 41 is transmissive relative to the wavelength of the light L2 irradiating the magnetic element 30. A portion of the light L2 passes through the electrode 41, and the light irradiates the magnetic element 30.

[0141] The optical device 105 of the sixth embodiment is an optical device that combines the structural features of the optical device 102 of the third embodiment with the structural features of the optical device 103 of the fourth embodiment. Therefore, the optical device 105 of the sixth embodiment has the same effects as these optical devices 102 and 103.

[0142] (Seventh Embodiment)

[0143] Figure 17This is a cross-sectional view of the characteristic portion of the optical device 106 according to the seventh embodiment. In the seventh embodiment, the same structures as in the above-described embodiments are labeled with the same reference numerals, and descriptions are omitted.

[0144] In the optical device 106, the substrate 10 supporting the laser diode 20 and the support 70 supporting the magnetic element 30 are different components. The laser diode 20 is located on or above the substrate 10. The magnetic element 30 is located on or above the support 70.

[0145] A magnetic element 30 is formed on a support 80. The support 80 is made of, for example, the same material as the support 70. The support 80 is disposed on the support 70 such that the side surface of the support 80 is opposite to the upper surface of the support 70 at the moment the magnetic element 30 is formed on the support 80.

[0146] Figure 18 This is a perspective view of the vicinity of the magnetic element 30 of the optical device 106 according to the seventh embodiment. The magnetic element 30 is held by electrodes 81 and 82. Electrode 81 is connected to a first terminal 85 and a second terminal 86. Electrode 82 is connected to the first terminal 85 via a through-hole wiring 83. Furthermore, electrode 82 is connected to the second terminal 86 via a through-hole wiring 84. The first terminal 85 and the second terminal 86 are formed on the side of the support 80.

[0147] exist Figure 17 In the example shown, the travel direction of light L2 emitted from the second emitting portion 25 of the laser diode 20 is aligned with the stacking direction of the magnetic element 30. The height position of the magnetic element 30 in the z-direction is, for example, aligned with the height position of the second emitting portion 25 of the laser diode 20 in the z-direction. Light L2 irradiates the magnetic element 30, for example, from the stacking direction of the magnetic element 30. In this case, the electrode 81 is transmissive relative to the wavelength of light L2 irradiating the magnetic element 30. A portion of the light L2 passes through the electrode 81, irradiating the magnetic element 30.

[0148] The optical device 106 of the seventh embodiment can use the magnetic element 30 to monitor the intensity change of at least a portion (at least a portion of L2) of the light emitted from the laser diode 20. That is, the optical device 106 can monitor the intensity change of the light L1 emitted from the laser diode 20 to the outside.

[0149] The present invention is not limited to the embodiments described above, and various modifications and alterations can be made within the scope of the spirit of the invention as described in the claims. For example, the structural features of the embodiments described above can be combined separately.

Claims

1. An optical device, wherein, have: A magnetic element comprising: a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; and laser diode, At least a portion of the light emitted from the laser diode illuminates the magnetic element. The state of the light emitted from the laser diode is monitored via the magnetic element.

2. The optical device according to claim 1, wherein, The laser diode has: a first emitting section and a second emitting section. At least a portion of the light emitted from the first or second emission portion illuminates the magnetic element.

3. The optical device according to claim 1, wherein, It also includes: substrate, The magnetic element and the laser diode are located on or above the substrate.

4. The optical device according to claim 2, wherein, It also includes: substrate, The magnetic element and the laser diode are located on or above the substrate.

5. The optical device according to claim 1, wherein, It also includes: a substrate and a support. The substrate and the support are different components. The laser diode is located on or above the substrate. The magnetic element is located above or on the support.

6. The optical device according to claim 2, wherein, It also includes: a substrate and a support. The substrate and the support are different components. The laser diode is located on or above the substrate. The magnetic element is located above or on the support.

7. The optical device according to any one of claims 1 to 6, wherein, It also features: a reflector, The reflector reflects at least a portion of the light emitted from the laser diode toward the magnetic element.

8. The optical device according to any one of claims 1 to 6, wherein, At least a portion of the light from the laser diode is irradiated onto the magnetic element from a direction intersecting the stacking direction of the magnetic element.

9. The optical device according to claim 7, wherein, At least a portion of the light from the laser diode is irradiated onto the magnetic element from a direction intersecting the stacking direction of the magnetic element.

10. The optical device according to any one of claims 1 to 6, wherein, At least a portion of the light from the laser diode is irradiated onto the magnetic element from the stacking direction of the magnetic element.

11. The optical device according to claim 7, wherein, At least a portion of the light from the laser diode is irradiated onto the magnetic element from the stacking direction of the magnetic element.

12. The optical device according to claim 8, wherein, At least a portion of the light from the laser diode is irradiated onto the magnetic element from the stacking direction of the magnetic element.

13. The optical device according to claim 9, wherein, At least a portion of the light from the laser diode is irradiated onto the magnetic element from the stacking direction of the magnetic element.

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