Transmitting and receiving device and transmitting device

Abstract

To provide a novel transmitting and receiving device.SOLUTION: A transmitting and receiving device includes a receiving device having a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and receiving an optical signal, a transmitting device having a modulated light output element and transmitting an optical signal, and a circuit chip having an integrated circuit electrically connected to the magnetic element and the modulated light output element, and the magnetic element and the modulated light output element are arranged in a direction perpendicular to the surface of the circuit chip, and the position of the circuit chip in the direction perpendicular to the surface is between the position of the magnetic element in the direction perpendicular to the surface and the position of the modulated light output element in the direction perpendicular to the surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a transmitting / receiving device and a transmitting device. [Background technology]

[0002] Photoelectric conversion elements are used for a variety of purposes.

[0003] With the spread of the Internet, communication volume has increased dramatically, and the importance of optical communication has increased. Optical communication is a communication method that converts electrical signals into optical signals and transmits and receives them using optical signals.

[0004] For example, Patent Document 1 describes a receiving device that receives an optical signal using a photodiode. The photodiode is, for example, a pn junction diode that uses a semiconductor pn junction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-292107 Summary of the Invention [Problem to be solved by the invention]

[0006] With the development of information and communication technology, there is a demand for even faster communication speeds. In optical communication, there is a demand for higher signal modulation frequencies. Photodetectors using semiconductor pn junctions are widely used as photoelectric conversion elements, but new breakthroughs are needed for further development.

[0007] The present invention has been made in view of the above problems, and has an object to provide a novel transmitting / receiving device. [Means for solving the problem]

[0008] In order to solve the above problems, the following means are provided.

[0009] (1) A transceiver according to a first aspect includes a receiving device having a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and receiving an optical signal; a transmitting device having a modulated light output element and transmitting an optical signal; and a circuit chip having an integrated circuit electrically connected to the magnetic element and the modulated light output element.

[0010] (2) In the transceiver according to the above aspect, the magnetic element and the modulated light output element may be arranged in a direction perpendicular to the surface of the circuit chip.

[0011] (3) In the transceiver according to the above aspect, the position of the circuit chip in the direction perpendicular to the surface may be between the position of the magnetic element in the direction perpendicular to the surface and the position of the modulated light output element in the direction perpendicular to the surface.

[0012] (4) In the transceiver according to the above aspect, the position of the magnetic element in the direction perpendicular to the surface may be between the position of the modulated light output element in the direction perpendicular to the surface and the position of the circuit chip in the direction perpendicular to the surface.

[0013] (5) In the transceiver according to the above aspect, the position of the modulated light output element in the direction perpendicular to the surface may be between the position of the magnetic element in the direction perpendicular to the surface and the position of the circuit chip in the direction perpendicular to the surface.

[0014] (6) In the transceiver according to the above aspect, the magnetic element and the modulated light output element may be located on the first surface side of the circuit chip, and the magnetic element and the modulated light output element may not overlap each other when viewed from the direction perpendicular to the surface.

[0015] (7) In the transceiver device according to the above aspect, the magnetic element and the integrated circuit may be electrically connected via a first through-wire that penetrates an insulating layer between the magnetic element and the integrated circuit, and the modulated light output element and the integrated circuit may be electrically connected via a second through-wire that penetrates an insulating layer between the modulated light output element and the integrated circuit.

[0016] (8) In the transmitting / receiving device according to the above aspect, the modulated light output element and the integrated circuit may be electrically connected via bumps between the transmitting device and the circuit chip.

[0017] (9) The transceiver according to the above aspect may further comprise a wiring chip having wiring electrically connected to the magnetic element, the modulated light output element, and the integrated circuit, wherein the magnetic element, the modulated light output element, and the circuit chip are on a first surface side of the wiring chip, and the modulated light output element, the modulated light output element, and the circuit chip do not overlap each other when viewed from a direction perpendicular to the surface of the wiring chip.

[0018] (10) In the transmitting / receiving device according to the above aspect, the modulated light output element may be an optical modulation element.

[0019] (11) In the transmitting / receiving device according to the above aspect, the optical modulation element may include a waveguide, and the waveguide may include lithium niobate.

[0020] (12) The transceiver according to the above aspect may further include an input unit that irradiates the magnetic element with light containing a signal, an output unit that outputs light containing a signal generated by the modulated light output element, a first fiber that connects the input unit to the outside, and a second fiber that connects the output unit to the outside. [Effects of the Invention]

[0021] The transceiver according to the above aspect is novel and creates a new breakthrough. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a conceptual diagram of a communication system according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the transmitting and receiving component according to the first embodiment. [Figure 3] 1 is a cross-sectional view of a transmitting / receiving device according to a first embodiment. [Figure 4] 3 is an enlarged cross-sectional view of a characteristic portion between the circuit chip and the transmitter according to the first embodiment. FIG. [Figure 5] FIG. 2 is a plan view of the receiving device according to the first embodiment. [Figure 6] FIG. 1 is a cross-sectional view of a magnetic element according to a first embodiment. [Figure 7] 5A and 5B are diagrams for explaining a first mechanism of a first operation example of the magnetic element according to the first embodiment. [Figure 8] 6A and 6B are diagrams illustrating a second mechanism of the first operation example of the magnetic element according to the first embodiment. [Figure 9] 6A and 6B are diagrams illustrating a first mechanism of a second operation example of the magnetic element according to the first embodiment. [Figure 10] 10A and 10B are diagrams illustrating a second mechanism of a second operation example of the magnetic element according to the first embodiment. [Figure 11] 10A and 10B are diagrams illustrating another example of the second operation example of the magnetic element according to the first embodiment. [Figure 12] 10A and 10B are diagrams illustrating another example of the second operation example of the magnetic element according to the first embodiment. [Figure 13] FIG. 2 is a plan view of an optical modulation element of the transmitting device according to the first embodiment. [Figure 14] 1 is a cross-sectional view of a light modulation element according to a first embodiment. [Figure 15] FIG. 10 is a cross-sectional view of a transmitting / receiving device according to a second embodiment. [Figure 16] FIG. 10 is a cross-sectional view of a transmitting / receiving device according to a third embodiment. [Figure 17] FIG. 10 is a cross-sectional view of a transmitting / receiving device according to a fourth embodiment. [Figure 18] FIG. 10 is a plan view of a transmitting / receiving device according to a fourth embodiment. [Figure 19] FIG. 10 is a cross-sectional view of a transmitting / receiving device according to a fifth embodiment. [Figure 20] FIG. 10 is a cross-sectional view of a transmitting / receiving device according to a sixth embodiment. [Figure 21] FIG. 10 is a plan view of a transmitting / receiving device according to a sixth embodiment. [Figure 22] FIG. 13 is a cross-sectional view of another example of the transceiver according to the sixth embodiment. [Figure 23] FIG. 13 is a cross-sectional view of a transmitting / receiving device according to a seventh embodiment. [Figure 24] FIG. 13 is a plan view of a transmitting / receiving device according to a seventh embodiment. [Figure 25] This is another application example of a communication system. [Figure 26] This is another application example of a communication system. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. The drawings used in the following description may show characteristic portions enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate changes can be made within the scope of the effects of the present invention.

[0024] The directions are defined below. The surface on which the substrate 31 constituting the circuit chip 35 described later extends is the xy plane, one direction within the plane is the x direction, and the direction within the plane perpendicular to the x direction is the y direction. The direction perpendicular to the surface on which the substrate 31 extends is the z direction. Hereinafter, the +z direction may be expressed as "up" and the -z direction as "down". The +z direction is the direction from the substrate 31 toward the insulating layer 34. Up and down do not necessarily coincide with the direction in which gravity is applied.

[0025] "First embodiment" FIG. 1 is a conceptual diagram of a communication system 200 according to a first embodiment. The communication system 200 shown in FIG. 1 includes a plurality of transmitting and receiving components 201 and a fiber 202 connecting the transmitting and receiving components 201. The communication system 200 can be used for short-distance or medium-distance communication, such as within a data center or between data centers, or for long-distance communication, such as between cities. The transmitting and receiving components 201 are installed, for example, within a data center or in a base station or backbone station of a long-distance communication network. The fiber 202 connects, for example, between data centers. The communication system 200 performs communication between the transmitting and receiving components 201 via, for example, the fiber 202. The communication system 200 may also perform communication between the transmitting and receiving components 201 wirelessly, without using the fiber 202.

[0026] 2 is a cross-sectional view of a transmitting and receiving component 201 according to the first embodiment. The transmitting and receiving component 201 includes a transmitting and receiving device 100, an input unit 110, an output unit 120, a first fiber 130, a second fiber 140, a connection unit 150, and a housing 160.

[0027] The transmitting and receiving part 201 is connected to the fiber 202 via the connection part 150. The connection part 150 is formed in the housing 160 and is exposed to the outside.

[0028] The first fiber 130 connects the connection portion 150 exposed to the outside and the input portion 110. The first fiber 130 is, for example, an optical fiber. The input portion 110 is located in the traveling direction of the light output from the end portion of the first fiber 130. The input portion 110 irradiates the light including the signal output from the end portion of the first fiber 130 to the receiving device 15 of the transmitting / receiving device 100. The input portion 110 is, for example, a mirror, a lens, etc. The light sent from the fiber 202 to the transmitting / receiving component 201 is irradiated to the receiving device 15 via the first fiber 130 and the input portion 110.

[0029] The second fiber 140 connects the connection unit 150 exposed to the outside and the output unit 120. The second fiber 140 is, for example, an optical fiber. The output unit 120 is connected to the transmitting device 25 of the transmitting / receiving device 100. The output unit 120 outputs light including a signal generated by the modulated light output element of the transmitting device 25. The output unit 120 is, for example, a lens. The light output from the transmitting device 25 propagates to the fiber 202 via the output unit 120 and the second fiber 140.

[0030] The transceiver 100 is housed in a housing 160. The transceiver 100 includes, for example, a receiver 15, a transmitter 25, and a circuit chip 35. The receiver 15, the transmitter 25, and the circuit chip 35 are stacked in the z direction.

[0031] FIG. 3 is a cross-sectional view of the transceiver 100 according to the first embodiment. The receiving device 15 and the transmitting device 25 are arranged in the z direction of the circuit chip 35. The receiving device 15 includes a magnetic element 10. The transmitting device 25 includes an optical modulation element 21. The magnetic element 10 and the optical modulation element 21 are arranged in the z direction of the circuit chip 35. The circuit chip 35 is located between the receiving device 15 and the transmitting device 25 in the z direction. The position of the circuit chip 35 in the z direction is between the position of the magnetic element 10 and the position of the optical modulation element 21 in the z direction. For example, the receiving device 15 (magnetic element 10) is located on the first surface 35S1 of the circuit chip 35, and the transmitting device 25 (optical modulation element 21) is located on the second surface 35S2 of the circuit chip 35. For example, the receiving device 15 (magnetic element 10) is located on the first surface 35S1 of the circuit chip 35, and the transmitting device 25 (optical modulation element 21) is located on the second surface 35S2 of the circuit chip 35. The first surface 35S1 and the second surface 35S2 are surfaces of the circuit chip 35 that face each other in the z direction.

[0032] The receiving device 15 includes, for example, a plurality of magnetic elements 10 and an insulating layer 12. Although FIG. 3 shows an example in which the receiving device 15 includes a plurality of magnetic elements 10, the receiving device 15 may include only one magnetic element 10. The receiving device 15 receives an optical signal input to the receiving device 15 from an input unit 110, and converts the received optical signal into an electrical signal using the magnetic element 10. Details of the magnetic element 10 will be described later.

[0033] The insulating layer 12 covers the periphery of the magnetic element 10. The insulating layer 12 is, for example, an oxide, nitride, or oxynitride of Si, Al, or Mg. The insulating layer 12 is, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al2O3), zirconium oxide (ZrO x ) etc.

[0034] The transmitting device 25 includes, for example, an optical modulation element 21. The transmitting device 25 transmits an optical signal modulated by the optical modulation element 21. The optical modulation element 21 includes a substrate 22, a covering layer 23, a waveguide 26, and an electrode 27. Details of the optical modulation element 21 will be described later. The transmitting device 25 is attached to the circuit chip 35 with, for example, an adhesive layer 70.

[0035] The circuit chip 35 includes a substrate 31, electronic components 32, wiring 33, and an insulating layer 34. The circuit chip 35 controls the operation of the receiving device 15 and the transmitting device 25. The substrate 31 is a semiconductor substrate, such as silicon. The electronic components 32 and wiring 33 are part of an integrated circuit 36. The integrated circuit 36 ​​is electrically connected to the magnetic element 10 and the optical modulation element 21. The electronic components 32 are, for example, transistors, capacitors, etc. The wiring 33 connects the electronic components 32 together, etc. The insulating layer 34 is an interlayer insulating layer, and can be made of the same material as the insulating layer 12. The insulating layer 34 covers the periphery of the electronic components 32 and wiring 33.

[0036] The magnetic element 10 is provided on an insulating layer 34. The integrated circuit 36 ​​(electronic components 32 or wiring 33) of the circuit chip 35 and the magnetic element 10 of the receiving device 15 are electrically connected via, for example, a through wire 50. The through wire 50 extends in the z direction. The through wire 50 penetrates, for example, in the z direction, an insulating layer between the magnetic element 10 and the integrated circuit 36 ​​(for example, a part of the insulating layer 34, or a part of the insulating layer 34 and the insulating layer 12). The through wire 50 connects the magnetic element 10 and the integrated circuit 36 ​​(electronic components 32 or wiring 33).

[0037] The integrated circuit 36 ​​of the circuit chip 35 and the optical modulation element 21 of the transmitter 25 are electrically connected via, for example, a through wire 60. The through wire 60 extends in the z direction. The through wire 60 penetrates, for example, in the z direction, an insulating layer (for example, the insulating substrate 22 and adhesive layer 70) between the optical modulation element 21 and the integrated circuit 36. The through wire 60 connects the optical modulation element 21 to the electronic component 32 or the wiring 33.

[0038] The transmitter 25 and the circuit chip 35, which sandwich the adhesive layer 70, may be electrically connected via bumps 63. FIG. 4 is an enlarged cross-sectional view of a characteristic portion between the circuit chip 35 and the transmitter 25 according to the first embodiment. The bumps 63 connect through-hole wires 61 that penetrate the substrate 31 of the circuit chip 35 with through-hole wires 62 that penetrate the substrate 22 of the transmitter 25. The bumps 63 are, for example, solder. The through-hole wires 61 electrically connect the integrated circuit 36 ​​and the bumps 63. The through-hole wires 62 electrically connect the optical modulation element 21 and the bumps 63. The optical modulation element 21 and the integrated circuit 36 ​​are electrically connected via the bumps 63 between the transmitter 25 and the circuit chip 35.

[0039] FIG. 5 is a plan view of the receiving device 15 according to the first embodiment as viewed from the z direction. The receiving device 15 converts the state or change in state of the irradiated light into an electrical signal. The receiving device 15 has, for example, a plurality of magnetic elements 10. As shown in FIG. 5, a plurality of magnetic elements 10 may be arranged within the spot sp of the irradiated light, or only one magnetic element 10 may be arranged.

[0040] The light irradiated to the receiving device 15 is not limited to visible light, but also includes infrared light, which has a longer wavelength than visible light, and ultraviolet light, which has a shorter wavelength than visible light. The wavelength of visible light is, for example, 380 nm or more and less than 800 nm. The wavelength of infrared light is, for example, 800 nm or more and 1 mm or less. The wavelength of ultraviolet light is, for example, 200 nm or more and less than 380 nm. The light irradiated to the receiving device 15 is, for example, light that includes a high-frequency optical signal and whose intensity varies. The high-frequency optical signal is, for example, a signal having a frequency of 100 MHz or more.

[0041] When the state of light irradiated onto each of the magnetic elements 10 changes, the voltage output from each of the magnetic elements 10 (the potential difference between the ends of each magnetic element in the z direction) changes in accordance with the change in the state of light. FIG. 6 is a cross-sectional view of the magnetic element 10 according to the first embodiment. The magnetic element 10 has, for example, a first ferromagnetic layer 1, a second ferromagnetic layer 2, a spacer layer 3, a first electrode 4, and a second electrode 5. The spacer layer 3 is located between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. The magnetic element 10 may have other layers in addition to these. Light is irradiated onto the magnetic element 10 from the side of the first ferromagnetic layer 1.

[0042] The magnetic element 10 is, for example, an MTJ (Magnetic Tunnel Junction) element in which the spacer layer 3 is made of an insulating material. In this case, the magnetic element 10 is an element in which the resistance value in the z direction (the resistance value when a current flows in the z direction) changes according to the relative change between the magnetization state of the first ferromagnetic layer 1 and the magnetization state of the second ferromagnetic layer 2. Such an element is also called a magnetoresistance effect element.

[0043] The first ferromagnetic layer 1 is a photodetection layer whose magnetization state changes when irradiated with external light. The first ferromagnetic layer 1 is also called a magnetization free layer. The magnetization free layer is a layer containing a magnetic material whose magnetization state changes when a predetermined external force is applied. The predetermined external force may be, for example, external light, a current flowing in the z-direction of the magnetic element 10, or an external magnetic field. The magnetization state of the first ferromagnetic layer 1 changes depending on the intensity of the light irradiated onto the first ferromagnetic layer 1. The magnetization direction of a ferromagnetic material can change in response to rapid changes in the intensity of the light irradiated onto the ferromagnetic material (high-frequency optical signal). Therefore, by using the first ferromagnetic layer 1 as a photodetection layer, the receiving device 15 can convert high-frequency optical signals into electrical signals, enabling high-speed optical communication.

[0044] The first ferromagnetic layer 1 includes a ferromagnetic material. In this specification, ferromagnetism includes ferrimagnetism. The first ferromagnetic layer 1 includes at least one of magnetic elements such as Co, Fe, or Ni. The first ferromagnetic layer 1 may include a nonmagnetic element such as B, Mg, Hf, or Gd in addition to the magnetic elements described above. The first ferromagnetic layer 1 may be, for example, an alloy including a magnetic element and a nonmagnetic element. The first ferromagnetic layer 1 may be composed of multiple layers. The first ferromagnetic layer 1 is, for example, a CoFeB alloy, a stack of a CoFeB alloy layer sandwiched between Fe layers, or a stack of a CoFeB alloy layer sandwiched between CoFe layers.

[0045] The first ferromagnetic layer 1 may be an in-plane magnetization film having an axis of easy magnetization in the in-plane direction (any direction in the xy plane) or a perpendicular magnetization film having an axis of easy magnetization in the direction perpendicular to the film plane (z direction).

[0046] The thickness of the first ferromagnetic layer 1 is, for example, 1 nm or more and 5 nm or less. The thickness of the first ferromagnetic layer 1 is preferably, for example, 1 nm or more and 2 nm or less. When the first ferromagnetic layer 1 is a perpendicular magnetization film, if the thickness of the first ferromagnetic layer 1 is thin, the perpendicular magnetic anisotropy applied by the layers above and below the first ferromagnetic layer 1 is strengthened, and the perpendicular magnetic anisotropy of the first ferromagnetic layer 1 is increased. In other words, if the perpendicular magnetic anisotropy of the first ferromagnetic layer 1 is high, the force that returns the magnetization to the z-direction is strengthened. On the other hand, if the thickness of the first ferromagnetic layer 1 is thick, the perpendicular magnetic anisotropy applied by the layers above and below the first ferromagnetic layer 1 is relatively weakened, and the perpendicular magnetic anisotropy of the first ferromagnetic layer 1 is weakened.

[0047] As the thickness of the first ferromagnetic layer 1 decreases, its volume as a ferromagnetic material decreases, and as it increases, its volume as a ferromagnetic material increases. The responsiveness of the magnetization of the first ferromagnetic layer 1 when external energy is applied is inversely proportional to the product (KuV) of the magnetic anisotropy (Ku) and volume (V) of the first ferromagnetic layer 1. In other words, as the product of the magnetic anisotropy and volume of the first ferromagnetic layer 1 decreases, its responsiveness to light increases. From this perspective, in order to enhance its responsiveness to light, it is preferable to reduce the volume of the first ferromagnetic layer 1 after appropriately designing the magnetic anisotropy of the first ferromagnetic layer 1.

[0048] If the thickness of the first ferromagnetic layer 1 is greater than 2 nm, an insertion layer made of, for example, Mo or W may be provided within the first ferromagnetic layer 1. That is, the first ferromagnetic layer 1 may be a stack in which a ferromagnetic layer, an insertion layer, and a ferromagnetic layer are stacked in this order in the z direction. The interfacial magnetic anisotropy at the interface between the insertion layer and the ferromagnetic layer enhances the perpendicular magnetic anisotropy of the entire first ferromagnetic layer 1. The thickness of the insertion layer is, for example, 0.1 nm to 0.6 nm.

[0049] The second ferromagnetic layer 2 is a magnetization fixed layer. The magnetization fixed layer is a layer made of a magnetic material whose magnetization state is less likely to change when a predetermined external energy is applied than the magnetization free layer. For example, the magnetization direction of the magnetization fixed layer is less likely to change when a predetermined external energy is applied than the magnetization free layer. Also, for example, the magnitude of the magnetization of the magnetization fixed layer is less likely to change when a predetermined external energy is applied than the magnetization free layer. The coercive force of the second ferromagnetic layer 2 is, for example, greater than the coercive force of the first ferromagnetic layer 1. The second ferromagnetic layer 2 has an easy axis of magnetization in the same direction as the first ferromagnetic layer 1, for example. The second ferromagnetic layer 2 may be an in-plane magnetization film or a perpendicular magnetization film.

[0050] The material constituting the second ferromagnetic layer 2 is, for example, the same as that of the first ferromagnetic layer 1. The second ferromagnetic layer 2 may be, for example, a laminate in which Co is 0.4 nm to 1.0 nm thick, Mo is 0.1 nm to 0.5 nm thick, a CoFeB alloy is 0.3 nm to 1.0 nm thick, and Fe is 0.3 nm to 1.0 nm thick are laminated in this order.

[0051] The magnetization of the second ferromagnetic layer 2 may be fixed by magnetic coupling with a third ferromagnetic layer via a magnetic coupling layer, for example. In this case, the combination of the second ferromagnetic layer 2, the magnetic coupling layer, and the third ferromagnetic layer may be referred to as a magnetization fixed layer.

[0052] The third ferromagnetic layer is magnetically coupled to the second ferromagnetic layer 2, for example. The magnetic coupling is, for example, an antiferromagnetic coupling caused by RKKY interaction. The material constituting the third ferromagnetic layer is, for example, the same as that of the first ferromagnetic layer 1. The magnetic coupling layer is, for example, Ru, Ir, or the like.

[0053] The spacer layer 3 is a non-magnetic layer disposed between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. The spacer layer 3 is composed of a layer made of a conductor, an insulator, or a semiconductor, or a layer containing current-carrying points made of a conductor in an insulator. The thickness of the spacer layer 3 can be adjusted depending on the orientation directions of the magnetizations of the first ferromagnetic layer 1 and the second ferromagnetic layer 2 in the initial state, which will be described later.

[0054] For example, when the spacer layer 3 is made of an insulator, the magnetic element 10 has a magnetic tunnel junction (MTJ) consisting of the first ferromagnetic layer 1, the spacer layer 3, and the second ferromagnetic layer 2. Such an element is called an MTJ element. In this case, the magnetic element 10 can exhibit a tunnel magnetoresistance (TMR) effect. For example, when the spacer layer 3 is made of a metal, the magnetic element 10 can exhibit a giant magnetoresistance (GMR) effect. Such an element is called a GMR element. The magnetic element 10 may be called an MTJ element, a GMR element, or other names depending on the material of the spacer layer 3, but is also collectively called a magnetoresistance effect element.

[0055] When the spacer layer 3 is made of an insulating material, a material containing aluminum oxide, magnesium oxide, titanium oxide, silicon oxide, or the like can be used. These insulating materials may also contain elements such as Al, B, Si, and Mg, or magnetic elements such as Co, Fe, and Ni. A high magnetoresistance ratio can be obtained by adjusting the thickness of the spacer layer 3 so that a high TMR effect is exhibited between the first ferromagnetic layer 1 and the second ferromagnetic layer 2. To efficiently utilize the TMR effect, the thickness of the spacer layer 3 may be approximately 0.5 to 5.0 nm, or approximately 1.0 to 2.5 nm.

[0056] When the spacer layer 3 is made of a nonmagnetic conductive material, conductive materials such as Cu, Ag, Au, or Ru can be used. To efficiently utilize the GMR effect, the thickness of the spacer layer 3 may be about 0.5 to 5.0 nm, or about 2.0 to 3.0 nm.

[0057] When the spacer layer 3 is made of a non-magnetic semiconductor material, it can be made of zinc oxide, indium oxide, tin oxide, germanium oxide, gallium oxide, ITO, etc. In this case, the thickness of the spacer layer 3 may be about 1.0 to 4.0 nm.

[0058] When a layer including current-carrying points formed by a conductor in a nonmagnetic insulator is used as the spacer layer 3, the current-carrying points may be formed by a nonmagnetic conductor such as Cu, Au, or Al in a nonmagnetic insulator made of aluminum oxide or magnesium oxide. The conductor may also be made of a magnetic element such as Co, Fe, or Ni. In this case, the thickness of the spacer layer 3 may be approximately 1.0 to 2.5 nm. The current-carrying points are, for example, columnar bodies with a diameter of 1 nm to 5 nm when viewed perpendicular to the film surface.

[0059] The magnetic element 10 may also have an underlayer, a cap layer, a perpendicular magnetization induction layer, etc. The underlayer is located below the second ferromagnetic layer 2. The underlayer is a seed layer or a buffer layer. The seed layer improves the crystallinity of the layer stacked on the seed layer. The seed layer is, for example, Pt, Ru, Hf, Zr, or NiFeCr. The seed layer has a thickness of, for example, 1 nm or more and 5 nm or less. The buffer layer is a layer that alleviates lattice mismatch between different crystals. The buffer layer is, for example, Ta, Ti, W, Zr, Hf, or nitrides of these elements. The buffer layer has a thickness of, for example, 1 nm or more and 5 nm or less.

[0060] The cap layer is located above the first ferromagnetic layer 1. The cap layer prevents damage to the lower layer during the process and improves the crystallinity of the lower layer during annealing. The thickness of the cap layer is, for example, 3 nm or less so that sufficient light is irradiated onto the first ferromagnetic layer 1. The cap layer is, for example, made of MgO, W, Mo, Ru, Ta, Cu, Cr, or a laminated film of these materials.

[0061] The perpendicular magnetization induction layer is formed when the first ferromagnetic layer 1 is a perpendicular magnetization film. The perpendicular magnetization induction layer is stacked on the first ferromagnetic layer 1. The perpendicular magnetization induction layer induces perpendicular magnetic anisotropy in the first ferromagnetic layer 1. The perpendicular magnetization induction layer is made of, for example, magnesium oxide, W, Ta, Mo, etc. When the perpendicular magnetization induction layer is made of magnesium oxide, it is preferable that the magnesium oxide has oxygen deficiency to increase conductivity. The film thickness of the perpendicular magnetization induction layer is, for example, 0.5 nm or more and 2.0 nm or less.

[0062] The first electrode 4 is in contact with, for example, the surface of the first ferromagnetic layer 1 opposite the spacer layer 3. The second electrode 5 is in contact with, for example, the surface of the second ferromagnetic layer 2 opposite the spacer layer 3. The first electrode 4 and the second electrode 5 sandwich the first ferromagnetic layer 1, the second ferromagnetic layer 2, and the spacer layer 3 in the z direction.

[0063] The first electrode 4 and the second electrode 5 are made of a conductive material. The first electrode 4 and the second electrode 5 are made of a metal such as Cu, Al, Au, or Ru. Ta or Ti may be laminated above and below these metals. The first electrode 4 and the second electrode 5 may also be a laminated film of Cu and Ta, a laminated film of Ta, Cu, and Ti, or a laminated film of Ta, Cu, and TaN. The first electrode 4 and the second electrode 5 may also be made of TiN or TaN.

[0064] The first electrode 4 and the second electrode 5 may be transparent to the wavelength region of light irradiated onto the first ferromagnetic layer 1. For example, the first electrode 4 and the second electrode 5 may be transparent electrodes containing an oxide transparent electrode material such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium gallium zinc oxide (IGZO). The first electrode 4 and the second electrode 5 may also be configured to have a plurality of metal pillars in these transparent electrode materials.

[0065] The magnetic element 10 is fabricated, for example, by stacking each layer, annealing, and processing. Each layer is formed, for example, by sputtering. Annealing is performed, for example, at a temperature of 250°C or higher and 450°C or lower. The stacked film is processed, for example, by photolithography and etching. The stacked film becomes a columnar magnetic element 10. The magnetic element 10 may be a cylinder or a prism. For example, the shortest width of the magnetic element 10 when viewed from the z direction may be 10 nm or higher and 2000 nm or lower, or 30 nm or higher and 500 nm or lower. The magnetic element 10 is obtained by the above processes.

[0066] The magnetic element 10 can be fabricated regardless of the material that constitutes the base, and therefore the receiver 15 can be fabricated directly on the circuit chip 35 without using an adhesive layer 70 or the like.

[0067] 6 shows an example of the magnetic element 10, but the magnetic element may be any element having a ferromagnetic material whose magnetization state changes when irradiated with light, and whose resistance value changes with the change in the magnetization state. The magnetic element may be, for example, the above-mentioned tunnel magnetoresistance effect element or giant magnetoresistance effect element, as well as an anisotropic magnetoresistance (AMR) effect element, a colossal magnetoresistance (CMR) effect element, or the like.

[0068] Next, several examples of the operation of the magnetic element 10 will be described. The first ferromagnetic layer 1 is irradiated with light whose intensity varies. The resistance value in the z direction of the magnetic element 10 changes when the first ferromagnetic layer 1 is irradiated with light. The output voltage from the magnetic element 10 changes when the first ferromagnetic layer 1 is irradiated with light. In the first operation example, a case will be described in which the intensity of the light irradiated to the first ferromagnetic layer 1 has two levels: a first intensity and a second intensity. The intensity of the light with the second intensity is greater than the intensity of the light with the first intensity. The first intensity may also be zero when the intensity of the light irradiated to the first ferromagnetic layer 1 is zero.

[0069] 7 and 8 are diagrams illustrating a first operation example of the magnetic element 10 according to the first embodiment. FIG. 7 is a diagram illustrating a first mechanism of the first operation example, and FIG. 8 is a diagram illustrating a second mechanism of the first operation example. In the upper graphs of FIGS. 7 and 8, the vertical axis represents the intensity of light irradiated to the first ferromagnetic layer 1, and the horizontal axis represents time. In the lower graphs of FIGS. 7 and 8, the vertical axis represents the resistance value of the magnetic element 10 in the z direction, and the horizontal axis represents time.

[0070] First, in a state where the first ferromagnetic layer 1 is irradiated with light of a first intensity (hereinafter referred to as the initial state), the magnetization M1 of the first ferromagnetic layer 1 and the magnetization M2 of the second ferromagnetic layer 2 are parallel, and the resistance value of the magnetic element 10 in the z direction is a first resistance value R1. The resistance value of the magnetic element 10 in the z direction is calculated using Ohm's law from the voltage generated across the magnetic element 10 by passing a sense current Is in the z direction of the magnetic element 10. The output voltage from the magnetic element 10 is generated between the first electrode 4 and the second electrode 5. In the example shown in FIG. 7 , the sense current Is is passed from the first ferromagnetic layer 1 to the second ferromagnetic layer 2. By passing the sense current Is in this direction, a spin transfer torque acts on the magnetization M1 of the first ferromagnetic layer 1 in the same direction as the magnetization M2 of the second ferromagnetic layer 2, and the magnetizations M1 and M2 become parallel in the initial state. Furthermore, by passing the sense current Is in this direction, it is possible to prevent the magnetization M1 of the first ferromagnetic layer 1 from being reversed during operation.

[0071] Next, the intensity of the light irradiated to the first ferromagnetic layer 1 changes from the first intensity to a second intensity. The second intensity is greater than the first intensity, and the magnetization M1 of the first ferromagnetic layer 1 changes from its initial state. The state of the magnetization M1 of the first ferromagnetic layer 1 when no light is irradiated to the first ferromagnetic layer 1 is different from the state of the magnetization M1 of the first ferromagnetic layer 1 at the second intensity. The state of the magnetization M1 refers to, for example, the tilt angle or magnitude with respect to the z direction.

[0072] For example, as shown in Fig. 7, when the intensity of light irradiated to the first ferromagnetic layer 1 changes from a first intensity to a second intensity, the magnetization M1 tilts with respect to the z direction. Also, as shown in Fig. 8, when the intensity of light irradiated to the first ferromagnetic layer 1 changes from the first intensity to a second intensity, the magnitude of the magnetization M1 decreases. For example, when the magnetization M1 of the first ferromagnetic layer 1 tilts with respect to the z direction due to the irradiation intensity of light, the tilt angle is greater than 0° and less than 90°.

[0073] When the magnetization M1 of the first ferromagnetic layer 1 changes from its initial state, the resistance value in the z direction of the magnetic element 10 exhibits a second resistance value R2. The second resistance value R2 is greater than the first resistance value R1. The second resistance value R2 is between the resistance value (first resistance value R1) when the magnetization M1 and the magnetization M2 are parallel and the resistance value when the magnetization M1 and the magnetization M2 are antiparallel.

[0074] In the case shown in FIG. 7, a spin transfer torque acts on the magnetization M1 of the first ferromagnetic layer 1 in the same direction as the magnetization M2 of the second ferromagnetic layer 2. Therefore, the magnetization M1 attempts to return to a state parallel to the magnetization M2, and when the intensity of the light irradiated to the first ferromagnetic layer 1 changes from the second intensity to the first intensity, the magnetic element 10 returns to its initial state. In the case shown in FIG. 8, when the intensity of the light irradiated to the first ferromagnetic layer 1 returns to the first intensity, the magnitude of the magnetization M1 of the first ferromagnetic layer 1 returns to its original value, and the magnetic element 10 returns to its initial state. In either case, the resistance value of the magnetic element 10 in the z direction returns to the first resistance value R1. In other words, when the intensity of the light irradiated to the first ferromagnetic layer 1 changes from the second intensity to the first intensity, the resistance value of the magnetic element 10 in the z direction changes from the second resistance value R2 to the first resistance value R1.

[0075] The resistance value in the z direction of the magnetic element 10 changes in response to changes in the intensity of light irradiated onto the first ferromagnetic layer 1. The output voltage from the magnetic element 10 changes in response to changes in the intensity of light irradiated onto the first ferromagnetic layer 1. In other words, the magnetic element 10 can convert changes in the intensity of the irradiated light into changes in the output voltage. In other words, the magnetic element 10 can convert a received optical signal into an electrical signal. The output voltage from the magnetic element 10 is sent to the integrated circuit 36, and the integrated circuit 36 ​​processes, for example, when the output voltage from the magnetic element 10 is equal to or greater than a threshold, as a first signal (e.g., "1"), and when it is less than the threshold, as a second signal (e.g., "0").

[0076] Here, the case where the magnetization M1 and the magnetization M2 are parallel in the initial state has been described as an example, but the magnetization M1 and the magnetization M2 may be antiparallel in the initial state. In this case, the resistance value in the z direction of the magnetic element 10 decreases as the state of the magnetization M1 changes (for example, as the angle change of the magnetization M1 from the initial state increases). If the initial state is one in which the magnetization M1 and the magnetization M2 are antiparallel, it is preferable to flow the sense current Is from the second ferromagnetic layer 2 toward the first ferromagnetic layer 1. By flowing the sense current Is in this direction, a spin transfer torque acts on the magnetization M1 of the first ferromagnetic layer 1 in the opposite direction to the magnetization M2 of the second ferromagnetic layer 2, and the magnetization M1 and the magnetization M2 become antiparallel in the initial state.

[0077] In the first operating example, the case where the light irradiated to the first ferromagnetic layer 1 has two levels of intensity, a first intensity and a second intensity, is described, but in the second operating example, the case where the intensity of the light irradiated to the first ferromagnetic layer 1 changes in multiple levels or in an analog manner is described.

[0078] 9 and 10 are diagrams for explaining a second operation example of the magnetic element 10 according to the first embodiment. FIG. 9 is a diagram for explaining a first mechanism of the second operation example, and FIG. 10 is a diagram for explaining a second mechanism of the second operation example. In the upper graphs of FIGS. 9 and 10, the vertical axis represents the intensity of light irradiated to the first ferromagnetic layer 1, and the horizontal axis represents time. In the lower graphs of FIGS. 9 and 10, the vertical axis represents the resistance value of the magnetic element 10 in the z direction, and the horizontal axis represents time.

[0079] 9, as the intensity of light irradiated onto the first ferromagnetic layer 1 increases, the external energy caused by the light irradiation tilts the magnetization M1 of the first ferromagnetic layer 1 from its initial state. The angle between the direction of the magnetization M1 of the first ferromagnetic layer 1 when no light is irradiated onto the first ferromagnetic layer 1 and the direction of the magnetization M1 when light is irradiated onto the first ferromagnetic layer 1 is both greater than 0° and smaller than 90°.

[0080] When the magnetization M1 of the first ferromagnetic layer 1 tilts from its initial state, the resistance value of the magnetic element 10 in the z direction changes. For example, the resistance value of the magnetic element 10 in the z direction changes from a second resistance value R2 to a third resistance value R3 to a fourth resistance value R4 in accordance with the tilt of the magnetization M1 of the first ferromagnetic layer 1. The resistance values ​​increase 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, the output voltage from the magnetic element 10 changes from a first voltage value to a second voltage value, a third voltage value, and a fourth voltage value in accordance with the tilt of the magnetization M1 of the first ferromagnetic layer 1. 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.

[0081] The resistance value of the magnetic element 10 in the z direction changes when the intensity of light irradiated onto the first ferromagnetic layer 1 changes. The output voltage from the magnetic element 10 changes when the intensity of light irradiated onto the first ferromagnetic layer 1 changes. For example, if the first voltage value is defined as "0," the second voltage value as "1," the third voltage value as "2," and the fourth voltage value as "3," the magnetic element 10 can output four-value information. Here, the case where four values ​​are read out is shown as an example, but the number of values ​​to be read out can be freely designed by setting the output voltage threshold. The magnetic element 10 may also output analog values ​​as they are.

[0082] Similarly, in the case of FIG. 10 , as the intensity of light irradiated onto the first ferromagnetic layer 1 increases, the magnitude of the magnetization M1 of the first ferromagnetic layer 1 decreases from its initial state due to external energy from the light irradiation. When the magnetization M1 of the first ferromagnetic layer 1 decreases from its initial state, the resistance value of the magnetic element 10 in the z direction changes. For example, depending on the magnitude of the magnetization M1 of the first ferromagnetic layer 1, the resistance value of the magnetic element 10 in the z direction changes from a second resistance value R2 to a third resistance value R3 to a fourth resistance value R4. That is, depending on the magnitude of the magnetization M1 of the first ferromagnetic layer 1, the output voltage from the magnetic element 10 changes from a first voltage value to a second voltage value, a third voltage value, and a fourth voltage value. Therefore, similar to the case of FIG. 9 , the magnetic element 10 can output the difference in these output voltages as multi-value or analog data.

[0083] Also, in the second operating example, as in the first operating example, when the intensity of the light irradiated to the first ferromagnetic layer 1 returns to the first intensity, the state of the magnetization M1 of the first ferromagnetic layer 1 returns to its original state, and the magnetic element 10 returns to its initial state.

[0084] Here, the case where the magnetization M1 and the magnetization M2 are parallel in the initial state has been described as an example, but also in the second operation example, the magnetization M1 and the magnetization M2 may be antiparallel in the initial state.

[0085] Although the first and second operation examples illustrate cases in which the magnetization M1 and the magnetization M2 are parallel or antiparallel in the initial state, the magnetization M1 and the magnetization M2 may be orthogonal in the initial state. For example, this applies when the first ferromagnetic layer 1 is an in-plane magnetization film in which the magnetization M1 is oriented in one direction in the xy plane, and the second ferromagnetic layer 2 is a perpendicular magnetization film in which the magnetization M2 is oriented in the z direction. Due to magnetic anisotropy, the magnetization M1 is oriented in one direction in the xy plane, and the magnetization M2 is oriented in the z direction, so that the magnetization M1 and the magnetization M2 are orthogonal in the initial state.

[0086] 11 and 12 are diagrams for explaining another example of the second operation example of the magnetic element 10 according to the first embodiment. The flow direction of the sense current Is applied to the magnetic element 10 differs between FIGS. 11 and 12. In FIG. 11, the sense current Is flows from the first ferromagnetic layer 1 to the second ferromagnetic layer 2. In FIG. 12, the sense current Is flows from the second ferromagnetic layer 2 to the first ferromagnetic layer 1.

[0087] 11 and 12, a spin transfer torque acts on the magnetization M1 in the initial state when the sense current Is flows through the magnetic element 10. In the case of FIG. 11, the spin transfer torque acts so that the magnetization M1 becomes parallel to the magnetization M2 of the second ferromagnetic layer 2. In the case of FIG. 12, the spin transfer torque acts so that the magnetization M1 becomes antiparallel to the magnetization M2 of the second ferromagnetic layer 2. In both the cases of FIG. 11 and 12, in the initial state, the effect of magnetic anisotropy on the magnetization M1 is greater than the effect of the spin transfer torque, so the magnetization M1 is oriented in one of the directions within the xy plane.

[0088] As the intensity of light irradiated onto the first ferromagnetic layer 1 increases, the magnetization M1 of the first ferromagnetic layer 1 tilts from its initial state due to the external energy generated by the light irradiation. This is because the sum of the effect of the light irradiation and the effect of the spin transfer torque acting on the magnetization M1 becomes greater than the effect of the magnetic anisotropy associated with the magnetization M1. As the intensity of light irradiated onto the first ferromagnetic layer 1 increases, the magnetization M1 in the case of FIG. 11 tilts so as to be parallel to the magnetization M2 of the second ferromagnetic layer 2, while the magnetization M1 in the case of FIG. 12 tilts so as to be antiparallel to the magnetization M2 of the second ferromagnetic layer 2. The tilt directions of the magnetization M1 in FIGS. 11 and 12 are different because the directions of the spin transfer torque acting on the magnetization M1 are different.

[0089] When the intensity of light irradiated to the first ferromagnetic layer 1 increases, the resistance value of the magnetic element 10 in the z direction decreases in the case of Fig. 11, and the resistance value of the magnetic element 10 in the z direction increases in the case of Fig. 12. That is, when the intensity of light irradiated to the first ferromagnetic layer 1 increases, the output voltage from the magnetic element 10 decreases in the case of Fig. 11, and the output voltage of the magnetic element 10 increases in the case of Fig. 12.

[0090] When the intensity of the light irradiated to the first ferromagnetic layer 1 returns to the first intensity, the state of the magnetization M1 of the first ferromagnetic layer 1 returns to its original state due to the effect of magnetic anisotropy on the magnetization M1, and as a result, the magnetic element 10 returns to its initial state.

[0091] Although the first ferromagnetic layer 1 is an in-plane magnetization film and the second ferromagnetic layer 2 is a perpendicular magnetization film, this relationship may be reversed. That is, in the initial state, the magnetization M1 may be oriented in the z direction, and the magnetization M2 may be oriented in any direction within the xy plane.

[0092] As described above, the receiver 15 receives an optical signal and converts the received optical signal into an electrical signal by the magnetic element 10 .

[0093] FIG. 13 is a plan view of the optical modulation element 21 of the transmitting device 25 according to the first embodiment, as viewed from the z direction. FIG. 14 is a cross-sectional view of the optical modulation element 21 according to the first embodiment. FIG. 14 is a cross-section taken along line AA in FIG. 13. The optical modulation element 21 converts an electrical signal into an optical signal. The optical modulation element 21 is an example of a modulated light output element. The optical modulation element 21 shown in FIGS. 13 and 14 is an example of an optical modulation element, and the configuration of the optical modulation element is not limited to this example.

[0094] The optical modulation element 21 comprises a substrate 22 , a covering layer 23 , a waveguide 26 and an electrode 27 .

[0095] The substrate 22 may include, for example, aluminum oxide. The substrate 22 may be, for example, sapphire. The coating layer 23 may be, for example, SiO2, Al2O3, MgF2, La2O3, ZnO, HfO2, MgO, Y2O3, CaF2, In2O3, or a mixture thereof.

[0096] The waveguide 26 includes, for example, an input waveguide 26A, a branching portion 26B, a first waveguide 26C, a second waveguide 26D, a coupling portion 26E, and an output waveguide 26F.

[0097] The input waveguide 26A receives the input light L in The branching portion 26B is located between the input waveguide 26A and the first and second waveguides 26C and 26D. in is input from the outside. Input light L in is, for example, a laser beam.

[0098] The first waveguide 26C and the second waveguide 26D extend, for example, in the x direction. The lengths of the first waveguide 26C and the second waveguide 26D in the x direction are, for example, approximately the same.

[0099] The coupling portion 26E is located between the first waveguide 26C and the second waveguide 26D and the output waveguide 26F. The output waveguide 26F is connected to the coupling portion 26E and outputs the output light L out and an output terminal from which the signal is output.

[0100] 14, the first waveguide 26C and the second waveguide 26D are configured by a part of a slab 28 and a ridge-shaped portion 28P. The slab 28 extends over the substrate 22. The ridge-shaped portion 28P protrudes from the upper surface of the slab 28. The slab 28 increases the electric field strength applied to the waveguide 26.

[0101] The slab 28 and the ridge-shaped portion 28P contain lithium niobate as a main component. Therefore, the waveguide 26 contains lithium niobate as a main component. Some elements of the lithium niobate may be substituted with other elements. The waveguide 26 is covered with, for example, a coating layer 23. The slab 28 and the ridge-shaped portion 28P may be made of a material other than lithium niobate. For example, the slab 28 and the ridge-shaped portion 28P may be made of silicon or silicon oxide with germanium oxide added, and the coating layer 23 may be silicon oxide. The input waveguide 26A, the branching portion 26B, the coupling portion 26E, and the output waveguide 26F also have the same configuration as the first waveguide 26C and the second waveguide 26D.

[0102] The electrodes 27 include, for example, electrodes 27A, 27B, and 27C. The electrodes 27A and 27B are located at positions where an electric field can be applied to at least a portion of the waveguide 26. An electric field can be applied to the first waveguide 26C from the electrode 27A. An electric field can be applied to the second waveguide 26D from the electrode 27B. The electrode 27A is located, for example, above the first waveguide 26C. The electrode 27B is located, for example, above the second waveguide 26D. The electrode 27C is located, for example, to the side of the electrodes 27A and 27B.

[0103] The electrodes 27A and 27B are connected to the integrated circuit 36 ​​(electronic components 32 or wiring 33) of the circuit chip 35. The electrode 27C is connected to a reference potential, which is, for example, ground.

[0104] A voltage is applied to electrode 27A from integrated circuit 36. Integrated circuit 36 ​​applies a modulated voltage to electrode 27A. A voltage is applied to electrode 27B from integrated circuit 36. Integrated circuit 36 ​​applies a modulated voltage to electrode 27B. The voltage applied to electrode 27A and the voltage applied to electrode 27B can be controlled independently.

[0105] Input light L input from input waveguide 26A in The light is branched and propagates through first waveguide 26C and second waveguide 26D. The phase difference between the light propagating through first waveguide 26C and the light propagating through second waveguide 26D is zero when the light is branched.

[0106] When a voltage is applied between electrodes 27A and 27C, an electric field is applied to first waveguide 26C, and the refractive index of the first waveguide changes due to the electro-optic effect. When a voltage is applied between electrodes 27B and 27C, an electric field is applied to second waveguide 26D, and the refractive index of second waveguide 26D changes due to the electro-optic effect.

[0107] When the refractive indexes of the first waveguide 26C and the second waveguide 26D are different, a phase difference occurs between the light propagating through the first waveguide 26C and the light propagating through the second waveguide 26D. The light propagating through the first waveguide 26C and the second waveguide 26D merges in the output waveguide 26F and is output from the optical modulation element 21 as output light L out is output as

[0108] Output light L out is a superposition of the light propagating through the first waveguide 26C and the light propagating through the second waveguide 26D. out The intensity of the output light L changes depending on the phase difference between the light propagating through the first waveguide 26C and the light propagating through the second waveguide 26D. For example, when the phase difference is an even multiple of π, the lights constructively interact with each other, resulting in a outThe intensity of becomes larger, and in the case of odd multiples of π, the light weakens each other, so the output light L out Based on this principle, the optical modulation element 21 modulates the input light L in The output light L out The transmitter 25 modulates the output light L modulated by the optical modulation element 21. out is transmitted as an optical signal.

[0109] In the transceiver 100 according to the first embodiment, a magnetic element 10 that converts a received optical signal into an electric signal and an optical modulation element 21 that outputs an optical signal, which is modulated light, are electrically connected to an integrated circuit 36 ​​that controls them, and the magnetic element 10 and the optical modulation element 21 are arranged in the z direction of a circuit chip 35. This allows the transceiver 100 according to the first embodiment to be miniaturized. Furthermore, the transceiver 100 according to the first embodiment can be handled as a single packaged electronic component, which makes it easy to connect it to other components such as a fiber 202.

[0110] Furthermore, the magnetic element 10 can be fabricated regardless of the material that constitutes the base, and can be fabricated on the circuit chip 35 without an adhesive layer 70 or the like. Therefore, in the transceiver 100 according to the first embodiment, the magnetic element 10 can be easily arranged in the z direction of the circuit chip 35, and miniaturization is easy.

[0111] "Second embodiment" 15 is a cross-sectional view of a transmitting / receiving device 101 according to the second embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0112] The transceiver 101 differs from the transceiver 100 according to the first embodiment in the stacking order of the receiving device 15, the transmitting device 25, and the circuit chip 35. In the transceiver 101, the circuit chip 35, the receiving device 15, and the transmitting device 25 are stacked in this order. The receiving device 15 and the transmitting device 25 are located on the first surface 35S1 side of the circuit chip 35. The magnetic element 10 and the optical modulation element 21 are located on the first surface 35S1 side of the circuit chip 35. The receiving device 15 is located between the circuit chip 35 and the transmitting device 25 in the z direction. The position of the magnetic element 10 in the z direction is between the position of the circuit chip 35 in the z direction and the position of the optical modulation element 21 in the z direction.

[0113] The receiving device 15 has a waveguide 11 on one side thereof. The waveguide 11 is located, for example, between the receiving device 15 and the transmitting device 25. One end of the waveguide 11 is located in the traveling direction of the light output from the end of the first fiber 130. The light including the signal output from the end of the first fiber 130 propagates through the waveguide 11 and is irradiated onto the magnetic element 10.

[0114] The transmitting device 25 is bonded to the receiving device 15, for example, with an adhesive layer 70. In the example shown in FIG. 15 , the substrate 22 of the transmitting device 25 and the waveguide 11 side of the receiving device 15 are bonded to each other with the adhesive layer 70 interposed therebetween. The integrated circuit 36 ​​of the circuit chip 35 and the optical modulation element 21 of the transmitting device 25 are electrically connected to each other via through-hole wiring 60. The through-hole wiring 60 penetrates an insulating layer (e.g., the insulating substrate 22, adhesive layer 70, insulating layer 12, and insulating layer 34) between the optical modulation element 21 and the integrated circuit 36 ​​in, for example, the z-direction. The through-hole wiring 60 connects the optical modulation element 21 and the integrated circuit 36. The optical modulation element 21 and the integrated circuit 36 ​​may be electrically connected to each other via bumps between the transmitting device 25 and the circuit chip 35, as in the first embodiment. In this case, the bumps between the transmitting device 25 and the circuit chip 35 are provided between the transmitting device 25 and the receiving device 15, sandwiching the adhesive layer 70 between them.

[0115] The transmitting / receiving device 101 according to the second embodiment can obtain the same effects as the transmitting / receiving device 100 according to the first embodiment.

[0116] "Third embodiment" 16 is a cross-sectional view of a transmitting / receiving device 102 according to the third embodiment. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0117] The transceiver 102 differs from the transceiver 100 according to the first embodiment in the stacking order of the receiving device 15, the transmitting device 25, and the circuit chip 35. In the transceiver 102, the circuit chip 35, the transmitting device 25, and the receiving device 15 are stacked in this order. The receiving device 15 and the transmitting device 25 are located on the second surface 35S2 side of the circuit chip 35. The magnetic element 10 and the optical modulation element 21 are located on the second surface 35S2 side of the circuit chip 35. The transmitting device 25 is located between the circuit chip 35 and the receiving device 15 in the z direction. The position of the optical modulation element 21 in the z direction is between the position of the circuit chip 35 in the z direction and the position of the magnetic element 10 in the z direction.

[0118] The transmitter 25 is bonded to the circuit chip 35 by, for example, an adhesive layer 70. In the example shown in FIG. 16 , the substrate 22 of the transmitter 25 and the substrate 31 of the circuit chip 35 are bonded to each other via the adhesive layer 70. The integrated circuit 36 ​​of the circuit chip 35 and the optical modulation element 21 of the transmitter 25 are electrically connected to each other via through-hole wiring 60. The through-hole wiring 60 penetrates an insulating layer (e.g., the insulating substrate 22, the adhesive layer 70, and the insulating substrate 31) between the optical modulation element 21 and the integrated circuit 36 ​​in, for example, the z-direction. The through-hole wiring 60 connects the optical modulation element 21 and the integrated circuit 36. The optical modulation element 21 and the integrated circuit 36 ​​may be electrically connected to each other via bumps between the transmitter 25 and the circuit chip 35, as in the first embodiment. In this case, the bumps between the transmitter 25 and the circuit chip 35 are provided between the substrate 22 and the substrate 31, sandwiching the adhesive layer 70.

[0119] The magnetic element 10 is provided, for example, on the covering layer 23 of the transmitting device 25. The integrated circuit 36 ​​of the circuit chip 35 and the magnetic element 10 of the receiving device 15 are electrically connected via a through-wire 50. The through-wire 50 penetrates, for example, in the z-direction, the insulating layers (e.g., the insulating layer 12, the covering layer 23, the substrate 22, the adhesive layer 70, and the insulating layer 34) between the magnetic element 10 and the integrated circuit 36. The through-wire 50 connects the magnetic element 10 and the integrated circuit 36.

[0120] The transmitting / receiving device 102 according to the third embodiment can obtain the same effects as the transmitting / receiving device 100 according to the first embodiment.

[0121] "Fourth embodiment" Fig. 17 is a cross-sectional view of the transceiver 103 according to the fourth embodiment. Fig. 18 is a plan view of the transceiver 103 according to the fourth embodiment. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0122] The transceiver 103 differs from the transceiver 100 according to the first embodiment in the arrangement of the receiving device 15 and the transmitting device 25. The receiving device 15 and the transmitting device 25 are located on the first surface 35S1 side of the circuit chip 35. The magnetic element 10 and the optical modulation element 21 are located on the first surface 35S1 side of the circuit chip 35. The receiving device 15 and the transmitting device 25 are located, for example, on the first surface 35S1 of the circuit chip 35. The receiving device 15 and the transmitting device 25 are located so as not to overlap each other when viewed from the z direction. The magnetic element 10 and the optical modulation element 21 are located so as not to overlap each other when viewed from the z direction.

[0123] The transmitter 25 is bonded to the circuit chip 35 by, for example, an adhesive layer 70. In the example shown in FIG. 17 , the substrate 22 of the transmitter 25 and the insulating layer 34 of the circuit chip 35 are bonded to each other via the adhesive layer 70. The integrated circuit 36 ​​of the circuit chip 35 and the optical modulation element 21 of the transmitter 25 are electrically connected to each other via through-hole wiring 60. The through-hole wiring 60 penetrates an insulating layer (e.g., the insulating substrate 22, the adhesive layer 70, and the insulating layer 34) between the optical modulation element 21 and the integrated circuit 36 ​​in, for example, the z-direction. The through-hole wiring 60 connects the optical modulation element 21 and the integrated circuit 36. The optical modulation element 21 and the integrated circuit 36 ​​may be electrically connected to each other via bumps between the transmitter 25 and the circuit chip 35, as in the first embodiment. In this case, the bumps between the transmitter 25 and the circuit chip 35 are provided between the substrate 22 and the insulating layer 34, sandwiching the adhesive layer 70.

[0124] The transmitting / receiving device 103 according to the fourth embodiment can obtain the same effects as the transmitting / receiving device 100 according to the first embodiment.

[0125] "Fifth embodiment" 19 is a cross-sectional view of a transmitting / receiving device 104 according to the fifth embodiment. In the fifth embodiment, the same components as those in the fourth embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0126] The transmitting / receiving device 104 has a transmitting device 40 instead of the transmitting device 25 of the transmitting / receiving device 103 of the fourth embodiment. The transmitting device 40 is equipped with a modulated light output element. The modulated light output element of the fifth embodiment is an element that outputs modulated light by directly switching the light output ON and OFF by switching the power supply ON and OFF. The modulated light output element of the fifth embodiment is, for example, a laser diode, a light emitting diode (LED), etc. When the frequency of the optical signal output from the transmitting device 40 is about several MHz, a modulated light output element that directly switches ON and OFF can be sufficient.

[0127] The transmitting / receiving device 104 according to the fifth embodiment can obtain the same effects as the transmitting / receiving device 100 according to the first embodiment.

[0128] "Sixth embodiment" Fig. 20 is a cross-sectional view of the transceiver 105 according to the sixth embodiment. Fig. 21 is a plan view of the transceiver 105 according to the sixth embodiment. In the sixth embodiment, the same components as those in the fourth embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0129] The transceiver 105 further includes a light source 80 in addition to the transceiver 103 of the fourth embodiment. The light source 80 is arranged in the z direction of the circuit chip. The light source 80 is on the first surface 35S1 side of the circuit chip 35. The light source 80 is arranged, for example, on the first surface 35S1 of the circuit chip 35. The receiving device 15, the transmitting device 25, and the light source 80 are positioned so as not to overlap each other when viewed from the z direction. The magnetic element 10, the optical modulation element 21, and the light source 80 are arranged so as not to overlap each other when viewed from the z direction.

[0130] The light source 80 emits input light L in The light source 80 is located to the side of the light modulation element 21. The light source 80 is, for example, a laser diode.

[0131] The transceiver 105 according to the sixth embodiment is packaged together with the light source 80. The transceiver 105 according to the sixth embodiment can obtain the same effects as the transceiver 100 according to the first embodiment.

[0132] Although FIG. 20 shows an example in which the light source 80 is incorporated into the transceiver 103 according to the fourth embodiment, the light source 80 may also be incorporated into the transceiver 100 to 102 according to the first to third embodiments. The light source 80 may be arranged on the same surface as the surface of the circuit chip 35 on which the optical modulation element 21 is arranged. FIG. 22 shows a modified example of the transceiver according to the fifth embodiment. The transceiver 105A shown in FIG. 22 is an example in which the light source 80 is incorporated into the transceiver 100 according to the first embodiment. In the example shown in FIG. 22, the light source 80 is on the second surface 35S2 side of the circuit chip 35.

[0133] Seventh Embodiment Fig. 23 is a cross-sectional view of the transceiver 106 according to the seventh embodiment. Fig. 24 is a plan view of the transceiver 106 according to the seventh embodiment. In the seventh embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0134] The transceiver 106 includes a receiving device 15, a transmitting device 25, a circuit chip 35, a light source 80, and a wiring chip 90. The receiving device 15, the transmitting device 25, the light source 80, and the circuit chip 35 are located on the first surface 90S1 side of the wiring chip 90. The magnetic element 10 and the optical modulation element 21 are located on the first surface 90S1 side of the wiring chip 90. The receiving device 15, the transmitting device 25, the light source 80, and the circuit chip 35 are arranged on the first surface 90S1 of the wiring chip 90. The receiving device 15, the transmitting device 25, the light source 80, and the circuit chip 35 are located so as not to overlap each other when viewed from the z direction. The magnetic element 10, the optical modulation element 21, and the circuit chip 35 are arranged so as not to overlap each other when viewed from the z direction.

[0135] The wiring chip 90 includes wiring 91 and an insulating layer 92. The wiring chip 90 is electrically connected to each of the magnetic element 10, the light modulation element 21, the light source 80, and the integrated circuit 36 ​​of the circuit chip 35 by through wiring 93. The wiring 91 and through wiring 93 electrically connect each of the magnetic element 10, the light modulation element 21, and the light source 80 to the integrated circuit 36 ​​of the circuit chip 35. The magnetic element 10 is connected to any of the wiring 91. The light modulation element 21 is connected to any of the wiring 91. The integrated circuit 36 ​​(electronic component 32 or wiring 33) is connected to any of the wiring 91. The magnetic element 10, the light modulation element 21, and the light source 80 are controlled by the integrated circuit 36 ​​of the circuit chip 35.

[0136] The transceiver 106 according to the seventh embodiment can achieve the same effects as the transceiver 100 according to the first embodiment. Furthermore, the transceiver 106 according to the seventh embodiment can be packaged after each element is manufactured separately, making it easy to optimize each element.

[0137] As described above, the present invention is not limited to the above-described embodiment and modifications, and various modifications and variations are possible within the scope of the gist of the present invention as set forth in the claims. For example, the characteristic features of the above-described embodiment and modifications may be combined.

[0138] For example, in the fifth embodiment, an example has been described in which a modulated light output element that directly switches on and off the light output is used instead of the light modulation element 21 of the fourth embodiment, but a modulated light output element that directly switches on and off the light output may be used instead of the light modulation element 21 of the first to third embodiments. Also, a modulated light output element that directly switches on and off the light output may be used instead of the light modulation element 21 and light source 80 of the sixth and seventh embodiments.

[0139] Further, up to this point, examples have been shown in which the transmitting / receiving device is applied to the communication system 200 shown in FIG. 1, taking the first to seventh embodiments as examples, but the communication system is not limited to this case.

[0140] For example, Fig. 25 is a conceptual diagram of another example of a communication system. A communication system 300 shown in Fig. 25 is communication between two mobile terminal devices 301. The mobile terminal devices 301 are, for example, smartphones, tablets, etc.

[0141] Each of the mobile terminal devices 301 includes the above-described transmitting / receiving device 100. The transmitting / receiving device 100 may be any of the transmitting / receiving devices 101 to 106 other than those of the first embodiment. An optical signal transmitted from the transmitting device 25 of one mobile terminal device 301 is received by the receiving device 15 of the other mobile terminal device 301. The light used for transmission and reception between the mobile terminal devices 301 is, for example, visible light. Each receiving device 15 has a magnetic element that converts the optical signal into an electric signal.

[0142] 26 is a conceptual diagram of another example of a communication system. A communication system 310 shown in Fig. 26 is for communication between a mobile terminal device 301 and an information processing device 302. The information processing device 302 is, for example, a personal computer.

[0143] The mobile terminal device 301 includes a transmitting / receiving device 100, and the information processing device 302 includes a receiving device 107. The transmitting / receiving device 100 may be any of the transmitting / receiving devices 101 to 106 other than those of the first embodiment. The information processing device 302 may include any of the transmitting / receiving devices 100 to 106 instead of the receiving device 107. An optical signal transmitted from the transmitting device 25 of the mobile terminal device 301 is received by the receiving device 15 of the information processing device 302. The light used for transmission and reception between the mobile terminal device 301 and the information processing device 302 is, for example, visible light. Each receiving device 15 has a magnetic element that converts the optical signal into an electric signal. [Explanation of symbols]

[0144] 1...first ferromagnetic layer, 2...second ferromagnetic layer, 3...spacer layer, 4...first electrode, 5...second electrode, 10...magnetic element, 11...waveguide, 12...insulating layer, 15...receiving device, 21...optical modulation element, 22...substrate, 23...covering layer, 25...transmitting device, 26...waveguide, 27...electrode, 28...slab, 28P...ridge-shaped portion, 31...substrate, 32...electronic component, 33, 91...wiring, 34, 92...insulating layer, 35...circuit chip, 35S1, 90S1...first surface, 35S2...second surface, 36...integrated circuit, 40...transmitting device, 50, 60, 61, 62, 93...through wiring, 63...bump, 70...adhesive layer, 80...light source, 90...wiring chip, 100, 101, 102, 103, 104, 105, 105A, 106...transmitting / receiving device, 107...receiving device, 110...input section, 120...output section, 130...first fiber, 140...second fiber, 150...connecting section, 160...housing, 200, 300, 310...communication system, 201...transmitting / receiving component, 202...fiber, 301...portable terminal device, 302...information processing device

Claims

1. a receiving device for receiving an optical signal, the receiving device having a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a transmitter having a modulated optical output element for transmitting an optical signal; a circuit chip having an integrated circuit electrically connected to the magnetic element and the modulated light output element; the magnetic element and the modulated light output element are arranged in a direction perpendicular to the surface of the circuit chip, a position of the circuit chip in the direction perpendicular to the surface between a position of the magnetic element in the direction perpendicular to the surface and a position of the modulated light output element in the direction perpendicular to the surface;

2. a receiving device for receiving an optical signal, the receiving device having a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a transmitter having a modulated optical output element for transmitting an optical signal; a circuit chip having an integrated circuit electrically connected to the magnetic element and the modulated light output element; the magnetic element and the modulated light output element are arranged in a direction perpendicular to the surface of the circuit chip, a position of the magnetic element in the direction perpendicular to the surface between a position of the modulated light output element in the direction perpendicular to the surface and a position of the circuit chip in the direction perpendicular to the surface;

3. a receiving device for receiving an optical signal, the receiving device having a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a transmitter having a modulated optical output element for transmitting an optical signal; a circuit chip having an integrated circuit electrically connected to the magnetic element and the modulated light output element; the magnetic element and the modulated light output element are arranged in a direction perpendicular to the surface of the circuit chip, a position of the modulated light output element in the direction perpendicular to the surface between a position of the magnetic element in the direction perpendicular to the surface and a position of the circuit chip in the direction perpendicular to the surface;

4. a receiving device for receiving an optical signal, the receiving device having a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a transmitter having a modulated optical output element for transmitting an optical signal; a circuit chip having an integrated circuit electrically connected to the magnetic element and the modulated light output element; the magnetic element and the modulated light output element are both located on a first surface side of the circuit chip; the magnetic element and the modulated light output element are positioned so as not to overlap each other when viewed from a direction perpendicular to the surface of the circuit chip, the magnetic element and the integrated circuit are electrically connected via a first through-wire that penetrates an insulating layer between the magnetic element and the integrated circuit; The modulated light output element and the integrated circuit are electrically connected via a second through-wire that penetrates an insulating layer between the modulated light output element and the integrated circuit.

5. 5. The transmitting / receiving device according to claim 1, wherein the modulated light output element and the integrated circuit are electrically connected via bumps between the transmitting device and the circuit chip.

6. 5. The transmitting / receiving device according to claim 1, wherein the modulated light output element is an optical modulation element.

7. the optical modulation element includes a waveguide; The transceiver of claim 6 , wherein the waveguide comprises lithium niobate.

8. an input unit that irradiates the magnetic element with light containing a signal; an output unit that outputs light containing a signal generated by the modulated light output element; a first fiber connecting the input unit to the outside; The transmitting / receiving device according to any one of claims 1 to 7, further comprising a second fiber connecting the output unit to an external device.

9. 9. The transmitting / receiving device according to claim 1, wherein the magnetic element changes the angle or magnitude of magnetization in accordance with the intensity of irradiated light, thereby changing the resistance in the stacking direction.

10. a modulated light output element; a circuit chip having an integrated circuit electrically connected to the modulated light output element; the modulated light output element has an insulating substrate, a waveguide provided on the substrate, and an electrode placed on the waveguide; the waveguide is provided on a first surface of the circuit chip via the substrate; The electrodes of the modulated light output element and the integrated circuit are electrically connected by through-wiring that penetrates the substrate in a direction perpendicular to the substrate.

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