Integrated Slot Waveguide Optical Phase Modulator

Abstract

An apparatus for modulating optical waves includes: a slot waveguide structure comprising: a first higher refractive index structure doped to include regions having a first conductivity type; a second higher refractive index structure doped to include regions having the first conductivity type; and one or more slot regions between the first and second higher refractive index structures. The one or more slot regions have a lower refractive index than the first and second higher refractive index structures. The apparatus includes a first support structure that allows the first higher refractive index structure to move to change the size of at least one of the one or more slot regions. The first support structure is doped to include regions having a second conductivity type different from the first conductivity type. The apparatus includes a second support structure that allows the second higher refractive index structure to move to change the size of at least one of the one or more slot regions. The second support structure is doped to include regions having a second conductivity type.

Description

Technical Field

[0001] This disclosure relates to an integrated slot waveguide optical phase modulator. Background Technology

[0002] An optical phase modulator is a device capable of altering the phase of an optical signal propagating through it. For example, an optical phase modulator is configured to change the phase of an eigenmode propagating in a waveguide by altering the refractive index of a material within the waveguide (e.g., the waveguide core). Optical phase modulators can be used in other devices, such as optical amplitude modulators in one or both arms of a Mach-Zehnder interferometer. Summary of the Invention

[0003] In general, an apparatus for modulating optical waves is provided. The apparatus includes: a slot waveguide structure comprising: a first higher refractive index structure doped to include regions having a first conductivity type; a second higher refractive index structure doped to include regions having the first conductivity type; and one or more slot regions between the first and second higher refractive index structures, the slot regions being substantially composed of a gas, liquid, or viscous material having a refractive index lower than that of the first and second higher refractive index structures. The apparatus further includes: a first support structure configured to allow the first higher refractive index structure to move to change the size of at least one of the one or more slot regions, wherein the first support structure is doped to include regions having a second conductivity type opposite to the first conductivity type; and a second support structure configured to allow the second higher refractive index structure to move to change the size of at least one of the one or more slot regions, wherein the second support structure is doped to include regions having a second conductivity type.

[0004] Implementations may include one or more of the following features. The slot waveguide structure may include a multi-slot waveguide structure, wherein one or more slot regions comprise two or more slot regions.

[0005] The slot waveguide structure may also include a third higher refractive index structure between the first higher refractive index structure and the second higher refractive index structure.

[0006] The first support structure is configured such that the first higher refractive index structure can move to change the size of the gap region between the first higher refractive index structure and the third higher refractive index structure; and the second support structure is configured such that the second higher refractive index structure can move to change the size of the gap region between the second higher refractive index structure and the third higher refractive index structure.

[0007] The device may further include: an input coupling structure configured to receive an optical wave and provide coupling between the spatial mode of the optical wave and the eigenmode of the slot waveguide structure; and an output coupling structure configured to provide coupling between the eigenmode of the slot waveguide structure and the spatial mode of the modulated optical wave, the modulated optical wave having been modulated at least in part based on a size variation in at least one of one or more slot regions during the propagation of the optical wave through the slot waveguide structure.

[0008] The doped regions of the first higher refractive index structure and the second higher refractive index structure can have substantially the same doping concentration.

[0009] The doped regions of the first support structure and the second support structure can have substantially the same doping concentration.

[0010] The doped region of the first support structure is electrically coupled to the first electrode, and the doped region of the second support structure is electrically coupled to the second electrode.

[0011] The device may also include a voltage source configured to provide a voltage between the first and second electrodes to cause a movement that changes the size of at least one of the one or more slit regions.

[0012] Slot waveguide structures may include a portion of the arm of an interferometric structure.

[0013] The device may include an interference structure, wherein the slot waveguide structure is part of an arm of the interference structure.

[0014] Slot waveguide structures can be configured to modulate the phase of light waves propagating in the arms of an interference structure.

[0015] An interference structure can be configured to modulate the amplitude of light waves propagating within it.

[0016] Interference structures can include Mach-Zehnder interferometers.

[0017] The first high refractive index structure and the first support structure can form an integrated structure.

[0018] The second higher refractive index structure and the second support structure can form an integrated structure.

[0019] The first higher refractive index structure, the second higher refractive index structure, the first support structure, and the second support structure can form an integrated structure.

[0020] The first and second support structures can form an integrated structure.

[0021] In another general aspect, an apparatus is provided comprising: a slot waveguide structure including: two or more higher refractive index structures, each higher refractive index structure being doped to include a region having a first conductivity type, and one or more slot regions between the two or more higher refractive index structures, the one or more slot regions having a lower refractive index compared to the refractive index of the two or more higher refractive index structures; the apparatus includes a support structure configured to support a corresponding higher refractive index structure and to enable the corresponding higher refractive index structure to move to change the size of at least one of the one or more slot regions, wherein each support structure is doped to have a second conductivity type opposite to the first conductivity type.

[0022] The implementation may include the following features. The device may include electrodes configured to allow a voltage to be applied across regions in a high-refractive-index structure doped with a first conductivity type and corresponding regions in a support structure doped with a second conductivity type.

[0023] In another general aspect, a system includes: a processor unit comprising: a light source configured to provide a plurality of optical outputs; and a plurality of optical modulators coupled to the light source and the first unit. The plurality of optical modulators are configured to generate an optical input vector by modulating the plurality of optical outputs provided by the light source based on a plurality of modulator control signals. The optical input vector includes a plurality of optical signals. The processor unit includes a matrix multiplication unit coupled to the plurality of optical modulators, the matrix multiplication unit being configured to convert the optical input vector into an output vector based on a plurality of weight control signals. At least one of the optical modulators includes any of the aforementioned means for modulating light waves.

[0024] The implementation may include the following features. Each of the optical modulators may include any of the devices described above.

[0025] In another general aspect, an optical processor includes a plurality of optical modulators, wherein at least one of the optical modulators includes any of the aforementioned devices.

[0026] The implementation may include the following features. Each of the plurality of optical modulators may include any of the devices described above.

[0027] In another general aspect, a system includes at least one of a robot, autonomous vehicle, autonomous drone, medical diagnostic system, fraud detection system, weather forecasting system, financial forecasting system, facial recognition system, voice recognition system, or product defect detection system. At least one of the robot, autonomous vehicle, autonomous drone, medical diagnostic system, fraud detection system, weather forecasting system, financial forecasting system, facial recognition system, voice recognition system, or product defect detection system includes any of the aforementioned devices.

[0028] In another general aspect, a method for manufacturing an optical modulator is provided. The method includes: forming a slot waveguide structure comprising: a first higher refractive index structure, a second higher refractive index structure, and one or more slot regions between the first and second higher refractive index structures, the slot regions being substantially composed of a gas, liquid, or viscous material having a refractive index lower than that of the first and second higher refractive index structures. The method includes forming a first support structure configured to support the first higher refractive index structure and to be movable to change the size of at least one of the one or more slot regions; forming a second support structure configured to support the second higher refractive index structure and to be movable to change the size of at least one of the one or more slot regions; doping the first higher refractive index structure to include a region having a first conductivity type; doping the second higher refractive index structure to include a region having a first conductivity type; doping the first support structure to include a region having a second conductivity type opposite to the first conductivity type; and doping the second support structure to include a region having a second conductivity type.

[0029] Implementation may include one or more of the following features. Forming the slot waveguide structure may include: forming a plurality of holes in a portion of a first support structure, forming a plurality of holes in a portion of a second support structure, and supplying gas through at least some of the holes to etch a portion of the material forming the first higher refractive index structure and the second higher refractive index structure, so that the first higher refractive index structure and the second higher refractive index structure are movable.

[0030] The doping of the first higher refractive index structure, the second higher refractive index structure, the first support structure, and the second support structure occurs before the formation of multiple pores within portions of the first and second support structures.

[0031] In another general aspect, a method for modulating an optical wave is provided, the method comprising: propagating an optical wave along a slotted waveguide structure, the slotted waveguide structure comprising: two or more suspended waveguide core structures defining one or more slot regions between the suspended waveguide core structures; and modulating the optical wave by generating an electromagnetic force to move the two or more suspended waveguide core structures and modify the size of the one or more slot regions between the suspended waveguide core structures, and modify the effective refractive index of the slotted waveguide structure.

[0032] The implementation may include one or more of the following features: The slotted waveguide structure may include support structures, each configured to support a corresponding suspended waveguide core structure. Generating electromagnetic forces may include generating repulsive forces to move the suspended waveguide core structure away from the corresponding support structure.

[0033] The slot waveguide structure may include support structures, each support structure being configured to support a corresponding suspended waveguide core structure, and generating electromagnetic forces may include generating attractive forces to move the suspended waveguide core structure toward the corresponding support structure.

[0034] Each suspended waveguide core structure may include a region doped to have a first conductivity type, and the corresponding support structure may include a region doped to have a second conductivity type opposite to the first conductivity type.

[0035] In another general aspect, an apparatus includes: a slot waveguide structure comprising: a first higher refractive index structure doped to include regions having a first conductivity type; a second higher refractive index structure doped to include regions having the first conductivity type; and one or more slot regions between the first and second higher refractive index structures, the slot regions having a lower refractive index than the first and second higher refractive index structures. The apparatus includes a first support structure configured to support the first higher refractive index structure and to be movable to change the size of at least one of the one or more slot regions, wherein the first support structure is doped to include regions having a second conductivity type different from the first conductivity type. The apparatus includes a second support structure configured to support the second higher refractive index structure and to be movable to change the size of at least one of the one or more slot regions, wherein the second support structure is doped to include regions having a second conductivity type.

[0036] This aspect may have one or more of the following advantages.

[0037] Modulation efficiency can be improved by doping portions of the slot waveguide structure and other support structures of an optical phase modulator, allowing the size of one or more slots in the slot waveguide structure to be changed using relatively low drive voltages. For example, in some embodiments, certain dopants are used to dope structures (also referred to herein as “supports”) that provide electromechanical support within a microelectromechanical system (MEMS) structure. The waveguide core suspended by the support can be doped with the same dopant, thus being doped with the same electron or hole carrier type (also referred to as the conduction type), and the support can be doped with an electron or hole carrier type opposite to that of the suspended waveguide core. The resultant forces generated when an electric field is applied using a drive voltage include attractive forces that draw the suspended waveguide core to its respective support and repulsive forces between the suspended waveguide cores. These forces make the optical phase modulator more efficient, thus requiring lower drive voltages.

[0038] Details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages of the invention will become apparent from the specification, drawings, and claims.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict with a patent application or patent application disclosure incorporated herein by reference, this specification (including the definitions) shall prevail. Attached Figure Description

[0040] This disclosure can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, by convention, the various features in the drawings are not drawn to scale. Instead, for clarity, the dimensions of the various features have been arbitrarily enlarged or reduced.

[0041] Figure 1A , Figure 1B and Figure 2 This is a schematic diagram of an example implementation of an optical phase modulator.

[0042] Figure 3A It is shown Figure 1A , Figure 1B A schematic diagram of the electrode structure of an optical phase modulator.

[0043] Figure 3B yes Figure 1A , Figure 1B A schematic diagram of the cross-sectional view of the structure inside the optical phase modulator.

[0044] Figures 4A-4C This is a schematic diagram of an example implementation of a slot waveguide structure with a different number of slots.

[0045] Figure 5 This is a flowchart of an example manufacturing process.

[0046] Similar reference numerals and names in various figures indicate similar elements. Detailed Implementation

[0047] refer to Figure 1A Example optical phase modulator 100 includes two supports 102A and 102B. Supports 102A and 102B are fixed in a specific location by a substrate structure 104 on which supports 102A and 102B are formed. For example, a solid block of material (e.g., formed of monocrystalline silicon) with a hole 106 formed along the top surface may be present to allow gas to pass through during etching of the hollow central cavity 108 below and / or other portions of the structure described herein.

[0048] In some embodiments, supports 102A and 102B are attached to the substrate structure 104 without the need to form the aperture 106. Lateral waveguide core structures 110A and 110B are also present, which are suspended by attaching their ends to the respective supports 102A and 102B. A central waveguide core structure 112 is also present between the lateral waveguide core structures 110A and 110B, attached to a different portion of the modulator (not shown). The region between the lateral waveguide core structures 110A and 110B and the central waveguide core structure 112 is called the slot region, or simply "slot". This is an example of a multi-slot waveguide structure (especially a two-slot waveguide structure) because two narrow slots 111A and 111B, respectively, exist between the central waveguide core and each of the two lateral waveguide cores 110A and 110B, where a large amount of optical energy is contained in the guided intrinsic modes. The light wave modulated by modulator 100 travels in a direction parallel to the longitudinal direction of the central waveguide core structure 112, and the light energy is contained in the central waveguide core structure 112, slots 111A and 111B, and the transverse waveguide core structures 110A and 110B. The effective refractive index varies in response to changes in the size (e.g., width) of slots 111A and 111B. In some examples, most of the light energy is contained in slots 111A and 111B, and changes in slot size can have a significant effect on the light wave.

[0049] Modulator 100 includes an input coupling structure (not shown) configured to receive an optical wave and provide coupling between the spatial mode of the optical wave and the eigenmode of the slot waveguide structure. Modulator 100 also includes an output coupling structure (not shown) configured to provide coupling between the eigenmode of the slot waveguide structure and the spatial mode of the modulated optical wave, which has been modulated at least in part based on a dimensional change in at least one of one or more slot regions during propagation of the optical wave through the slot waveguide structure.

[0050] To allow movement of the transverse waveguide core structure, thereby altering the effective refractive index of the eigenmode by corresponding changes in the slot size, these slots can move without obstruction (or with reduced obstruction). For example, the slots can substantially comprise air or other gases, liquids, or viscous materials. Furthermore, any such gas, liquid, or viscous material may have a lower refractive index than the material forming the waveguide core structure (e.g., silicon or other semiconductor materials that can be doped). Alternatively, other examples may have more than two slots, or only one slot, depending on how many waveguide core structures are included in the overall modulator device, as referenced below. Figures 4A-4C As stated above.

[0051] In some embodiments, etching is used to form gaps between the lateral waveguide core structure 110A and the central waveguide core structure 112, as well as gaps between the lateral waveguide core structure 110B and the central waveguide core structure 112. Etching is also used to form open spaces between the lateral waveguide core structure 110A and the adjacent support 102A, as well as open spaces between the lateral waveguide core structure 110B and the adjacent support 102B.

[0052] Lateral waveguide core structures 110A and 110B are doped with the same dopant, which has a specific electron or hole charge carrier type, also known as the conduction type. For example, an n-type dopant or impurity can be used to provide donor electrons for the electron charge carrier type (or electron conduction type). Supports 102A and 102B are doped with the same dopant, but with opposite charge carrier types compared to the dopant in lateral waveguide core structures 110A and 110B. For example, a p-type dopant or impurity, acting as an electron acceptor, can be used for the hole charge carrier type (or hole conduction type).

[0053] For example, refer to a top view showing a portion of the optical phase modulator 100 (at different scales for ease of observation). Figure 1B Supports 102A and 102B may be doped with p-type dopant, and lateral waveguide core structures 110A and 110B may be doped with n-type dopant. As another example, supports 102A and 102B may be doped with n-type dopant, and lateral waveguide core structures 110A and 110B may be doped with p-type dopant. When an electric field is applied, as described in more detail below, lateral waveguide core structures 110A and 110B repel each other and are attracted to their respective supports 102A and 102B. The central waveguide core structure 112 is undoped and therefore does not move in response to the applied electric field. These electromagnetic repulsion and attraction forces allow the gap width to be varied in an efficient manner (e.g., more efficient than mechanical forces used in other devices in some cases). In some embodiments, the doping concentrations of p-type and n-type dopant may be substantially equal in the waveguide core structures and adjacent supports. In some manufacturing processes, partial doping of the material occurs before the formation of the aperture 106 to allow the structure to be fully formed.

[0054] For example, a multi-slot waveguide nano-optical-electromechanical phase modulator uses a slotted waveguide structure with an effective refractive index of intrinsic modes that vary according to the size of the gaps between the suspended waveguide cores. The modulator is driven by a mechanical actuator that moves the suspended waveguide cores to change the size of the slots. The suspended waveguide cores can be made of undoped or lightly doped semiconductor materials. Compared to this multi-slot waveguide nano-optical-electromechanical phase modulator, an optical phase modulator 100 (or 200) uses electrical and / or electromagnetic repulsive and attractive forces to change the width of one or more slots in a more efficient manner.

[0055] In some embodiments, supports 102A and 102B are relatively close to the transverse waveguide core structures 110A and 110B, so the attraction between them (due to opposite charges) will be relatively large. Therefore, the voltage required to achieve the slot width variation (due to the deformation of the transverse waveguide core structures) is relatively low. For example, a relatively low voltage may be required to achieve a particular modulation efficiency compared to the voltage used to modulate the piezoelectric actuator that will be used to apply mechanical force.

[0056] refer to Figure 2 Another exemplary optical phase modulator 200 includes two supports 202A and 202B. The supports are fixed in place by a substrate structure 204 forming the supports 202A and 202B. In this example, the supports 202A and 202B are formed by applying a layer of another material (e.g., a polycrystalline silicon layer) different from the material of the substrate structure 204 (e.g., a monocrystalline silicon material). Alternatively, a solid block of material with a hole 206 formed along the top surface may be present to allow gas to pass through during etching of the hollow central cavity 208 below. Lateral waveguide core structures 210A and 210B are also present, which are suspended by attaching their ends to a support structure comprising the respective supports 202A and 202B and a portion of the substrate structure 204. A central waveguide core structure 212 is also present between the lateral waveguide core structures 210A and 210B, which is attached to a different portion of the modulator (not shown). In this example, the polysilicon supports 202A and 202B and the suspended waveguide core structures 210A and 210B are located on different layers. An attractive force will still exist between the supports 202A and 202B and the corresponding suspended waveguide core structures 210A and 210B, although this force can be less than that in the example of Figure 1 because the supports 202A and 202B are not directly opposite the suspended waveguide core structures 210A and 210B.

[0057] refer to Figure 3A and 3B Top view 300 shows different regions of a portion of an optical phase modulator, and cross-sectional view 350 shows different structures of the optical phase modulator electrically attached to the anode and cathode contacts shown in top view 300. Top view 300 shows a suspended region 302 including a portion of a suspended waveguide core structure and side supports, and a non-suspended region 304 including metal electrodes 306A-306D for electrical contact with the heavily doped region below. In some embodiments, the doping concentration varies from a lightly doped portion of the suspended region 302 (e.g., to reduce associated losses experienced by the guided light wave) to a heavily doped portion of the non-suspended region 304 (e.g., for low contact resistance of electrodes 306A-306D).

[0058] refer to Figure 3B Cross-sectional view 350 shows p-type doped supports 352A and 352B, n-type doped suspended waveguide core structures 352C and 352D, and an undoped center waveguide core structure 354. For example, for the longitudinally extending center waveguide core structure 112 ( Figure 1A , Figure 1B Cross-sectional view 350 shows the relative positions of p-type doped supports 352A and 352B, n-type doped suspended waveguide core structures 352C and 352D, and an undoped central waveguide core structure 354 in a plane perpendicular to the longitudinal direction. Anode electrodes 306A and 306B are electrically connected to the heavily doped regions extending to the p-type doped supports 352A and 352B, and cathode electrodes 306C and 306D are electrically connected to the heavily doped regions extending to the n-type doped supports 352C and 352D.

[0059] When a positive (negative) voltage from a voltage source (not shown) is applied between the anode and cathode electrodes (e.g., the anode has a higher (lower) voltage than the cathode), the suspended waveguide core structure will move closer (away) from the adjacent support. As the space between the suspended waveguide core structure and the center waveguide increases (decreases), the effective refractive index guiding the intrinsic modes decreases (increases). The greater the voltage difference (ΔV) between the anode and cathode electrodes, the greater the movement of the suspended waveguide core structure. For example, as... Figure 3B As shown, if ΔV2 > ΔV1, the (lateral) movement of the suspended waveguide core structure toward the adjacent support is greater under ΔV2 than under ΔV1. In some embodiments, the metal electrodes 306A-306D are fabricated as through-holes forming from the top surface to the heavily doped region in the lower layer.

[0060] The example above illustrates a slot waveguide structure with two slots. Figures 4A-4C Example implementations of slot waveguide structures with different numbers of slots are shown. Figure 4A A slot waveguide structure 400 is shown, having two floating waveguide core structures 402A and 402B and a slot 404. Figure 4B A multi-slot waveguide structure 410 with four floating waveguide core structures 412A-412D and three slots 414A-414C is shown. Figure 4C A slotted waveguide structure 420 with five floating waveguide core structures 422A-422E and four slots 424A-424D is shown. Any such phase-modulated slotted waveguide can be included in an integrated photonic device. In some devices, one or more such phase modulators can be used in an interferometric arrangement to modulate the amplitude of light that has been phase-shifted and combined in an interferometric manner. For example, a Mach-Zehnder interferometer (MZI) can include a phase-modulated multi-slotted waveguide on at least a portion of one or two arms of the MZI.

[0061] Figure 5 An example of a fabrication process 500 for manufacturing a slotted waveguide optical phase modulator is shown. Process 500 includes forming (502) a slotted waveguide structure comprising: a first higher refractive index structure, a second higher refractive index structure, and one or more slot regions between the first and second higher refractive index structures, the slot regions being substantially composed of a gas, liquid, or viscous material having a refractive index lower than that of the first and second higher refractive index structures. Process 500 includes forming (504) a first support structure configured to support the first higher refractive index structure and to be movable to change the size of at least one of the one or more slot regions. Process 500 includes forming (506) a second support structure configured to support the second higher refractive index structure and to be movable to change the size of at least one of the one or more slot regions. Process 500 includes doping (508) the first higher refractive index structure to include a region having a first conductivity type. Process 500 includes doping (510) a second higher refractive index structure to include a region having a first conductivity type. Process 500 includes doping (512) a first support structure to include a region having a second conductivity type opposite to the first conductivity type. Process 500 includes doping (514) a second support structure to include a region having a second conductivity type. These fabrication steps can be performed in any order.

[0062] While this disclosure has been described in conjunction with certain embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which should be interpreted in the broadest possible sense to cover all such modifications and equivalent structures permitted by law.

[0063] Although the invention is defined in the appended claims, it should be understood that the invention may also be defined according to the following set of embodiments:

[0064] Example 1: A device for modulating light waves, the device comprising:

[0065] Slot waveguide structure, comprising:

[0066] A first higher refractive index structure doped to include regions having a first conductivity type, and a second higher refractive index structure doped to include regions having the first conductivity type, and

[0067] One or more gap regions between the first higher refractive index structure and the second higher refractive index structure, the gap regions being substantially composed of a gas, liquid or viscous material having a lower refractive index than the first higher refractive index structure and the second higher refractive index structure;

[0068] A first support structure is configured to support the first higher refractive index structure and enable the first higher refractive index structure to move to change the size of at least one of the one or more gap regions, wherein the first support structure is doped to include a region having a second conductivity type opposite to the first conductivity type; and

[0069] A second support structure is configured to support the second higher refractive index structure and enable the second higher refractive index structure to move to change the size of at least one of the one or more gap regions, wherein the second support structure is doped to include regions having the second conductivity type.

[0070] Example 2: According to the device described in Example 1, the slot waveguide structure includes a multi-slot waveguide structure, wherein one or more slot regions include two or more slot regions.

[0071] Example 3: According to the device described in Example 2, the slot waveguide structure further includes a third higher refractive index structure between the first higher refractive index structure and the second higher refractive index structure.

[0072] Example 4: The apparatus according to Example 3, wherein:

[0073] The first support structure is configured such that the first higher refractive index structure can move to change the size of the gap region between the first higher refractive index structure and the third higher refractive index structure; and

[0074] The second support structure is configured such that the second higher refractive index structure can move to change the size of the gap region between the second higher refractive index structure and the third higher refractive index structure.

[0075] Example 5: The apparatus according to any one of Examples 1 to 4 further includes:

[0076] An input coupling structure configured to receive the light wave and provide coupling between the spatial mode of the light wave and the eigenmode of the slotted waveguide structure; and

[0077] An output coupling structure is configured to provide coupling between the intrinsic mode of the slot waveguide structure and the spatial mode of the modulated optical wave, which has been modulated at least in part based on a size variation in at least one of the one or more slot regions during the propagation of the optical wave through the slot waveguide structure.

[0078] Example 6: The apparatus according to any one of Examples 1 to 5, wherein the doped region of the first higher refractive index structure and the doped region of the second higher refractive index structure have substantially equal doping concentrations.

[0079] Example 7: According to the apparatus of Example 6, wherein the doped region of the first support structure and the doped region of the second support structure have substantially equal doping concentrations.

[0080] Example 8: The apparatus according to any one of Examples 1 to 7, wherein the doped region of the first support structure is electrically coupled to the first electrode, and the doped region of the second support structure is electrically coupled to the second electrode.

[0081] Example 9: The apparatus according to Example 8 further includes a voltage source configured to provide a voltage between the first electrode and the second electrode to cause a movement that changes the size of at least one of the one or more slit regions.

[0082] Example 10: The device according to any one of Examples 1 to 9, wherein the slot waveguide structure includes a portion of an arm of an interference structure.

[0083] Example 11: The device according to any one of Examples 1 to 9 includes an interference structure, wherein the slot waveguide structure is part of an arm of the interference structure.

[0084] Example 12: The apparatus according to Example 10 or 11, wherein the slot waveguide structure is configured to modulate the phase of the light wave propagating in the arm of the interference structure.

[0085] Example 13: The apparatus according to Example 12, wherein the interference structure is configured to modulate the amplitude of the light wave propagating in the interference structure.

[0086] Example 14: The apparatus according to Example 10 or 11, wherein the interference structure includes a Mach-Zehnder interferometer.

[0087] Example 15: The apparatus according to any one of Examples 1 to 14, wherein the first higher refractive index structure and the first support structure form an integrated structure.

[0088] Example 16: The apparatus according to Example 15, wherein the second higher refractive index structure and the second support structure form an integrated structure.

[0089] Example 17: The apparatus according to Example 16, wherein the first higher refractive index structure, the second higher refractive index structure, the first support structure and the second support structure form an integrated structure.

[0090] Example 18: The apparatus according to any one of Examples 1 to 16, wherein the first support structure and the second support structure form an integrated structure.

[0091] Example 19: An apparatus comprising:

[0092] Slot waveguide structure, comprising:

[0093] Two or more higher refractive index structures, each higher refractive index structure being doped to include a region having a first conductivity type, and

[0094] One or more gap regions between the two or more higher refractive index structures have a lower refractive index than the refractive index of the two or more higher refractive index structures; and

[0095] A support structure configured to support a corresponding higher refractive index structure and enable the corresponding higher refractive index structure to move to change the size of at least one of the one or more gap regions, wherein each support structure is doped to have a second conductivity type opposite to the first conductivity type.

[0096] Example 20: The apparatus according to Example 19 includes an electrode configured to apply a voltage across a region in the high refractive index structure doped to have a first conductivity type and a corresponding region in the support structure doped to have a second conductivity type.

[0097] Example 21: A system comprising:

[0098] Processor unit, comprising:

[0099] A light source configured to provide multiple light outputs;

[0100] A plurality of optical modulators coupled to the light source and the first unit, the plurality of optical modulators being configured to generate an optical input vector comprising a plurality of optical signals by modulating the plurality of light outputs provided by the light source based on a plurality of modulator control signals; and

[0101] A matrix multiplication unit coupled to the plurality of optical modulators, the matrix multiplication unit being configured to convert the optical input vector into an output vector based on a plurality of weight control signals;

[0102] At least one of the optical modulators includes the means according to any one of embodiments 1 to 20.

[0103] Example 22: The system according to Example 21, wherein each of the optical modulators includes the means according to any one of Examples 1 to 20.

[0104] Example 23: An optical processor comprising a plurality of optical modulators, wherein at least one of the optical modulators comprises a device according to any one of Examples 1 to 20.

[0105] Example 24: The optical processor according to Example 23, wherein each of the plurality of optical modulators includes the means according to any one of Examples 1 to 20.

[0106] Example 25: A system comprising at least one of a robot, an autonomous vehicle, an autonomous drone, a medical diagnostic system, a fraud detection system, a weather forecasting system, a financial forecasting system, a facial recognition system, a voice recognition system, or a product defect detection system.

[0107] At least one of the following includes a device according to any one of embodiments 1 to 20: a robot, an autonomous vehicle, an autonomous drone, a medical diagnostic system, a fraud detection system, a weather forecasting system, a financial forecasting system, a facial recognition system, a voice recognition system, or a product defect detection system.

[0108] Example 26: A method for manufacturing an optical modulator, the method comprising:

[0109] Forming a slotted waveguide structure, which includes:

[0110] The first high refractive index structure,

[0111] The second higher refractive index structure, and

[0112] One or more gap regions between the first higher refractive index structure and the second higher refractive index structure, the gap regions being substantially composed of a gas, liquid or viscous material having a lower refractive index than the first higher refractive index structure and the second higher refractive index structure;

[0113] A first support structure is formed, the first support structure being configured to support the first higher refractive index structure and enable the first higher refractive index structure to move to change the size of at least one of the one or more gap regions.

[0114] A second support structure is formed, the second support structure being configured to support the second higher refractive index structure and enable the second higher refractive index structure to move to change the size of at least one of the one or more gap regions;

[0115] The first higher refractive index structure is doped to include a region having a first conductivity type;

[0116] The second higher refractive index structure is doped to include a region having the first conductivity type;

[0117] Doping the first support structure to include a region having a second conductivity type opposite to the first conductivity type; and

[0118] The second support structure is doped to include regions having the second conductivity type.

[0119] Example 27: According to the method of Example 26, forming the slot waveguide structure includes: forming a plurality of holes in a portion of the first support structure, forming a plurality of holes in a portion of the second support structure, and providing gas through at least some of the plurality of holes to etch a portion of the material forming the first higher refractive index structure and the second higher refractive index structure, so that the first higher refractive index structure and the second higher refractive index structure are movable.

[0120] Example 28: According to the method of Example 27, the doping of the first higher refractive index structure, the second higher refractive index structure, the first support structure and the second support structure occurs before the plurality of holes are formed in portions of the first support structure and the second support structure.

[0121] Example 29: A method for modulating light waves, the method comprising:

[0122] Optical waves propagate along a slotted waveguide structure, the slotted waveguide structure comprising:

[0123] Two or more suspended waveguide core structures defining one or more gap regions between the suspended waveguide core structures; and

[0124] The light waves are modulated by generating electromagnetic force to move the two or more suspended waveguide core structures and modify the size of the one or more gap regions between the suspended waveguide core structures, and modify the effective refractive index of the gap waveguide structure.

[0125] Example 30: According to the method of Example 29, the slot waveguide structure includes a support structure, each support structure is configured to support a corresponding suspended waveguide core structure, and generating the electromagnetic force includes generating a repulsive force to move the suspended waveguide core structure away from the corresponding support structure.

[0126] Example 31: According to the method of Example 29, the slot waveguide structure includes a support structure, each support structure is configured to support a corresponding suspended waveguide core structure, and generating the electromagnetic force includes generating an attractive force to move the suspended waveguide core structure toward the corresponding support structure.

[0127] Example 32: The method according to any one of Examples 29 to 31, wherein each suspended waveguide core structure includes a region doped to have a first conductivity type, and the corresponding support structure includes a region doped to have a second conductivity type opposite to the first conductivity type.

[0128] Example 33: An apparatus comprising:

[0129] Slot waveguide structure, comprising:

[0130] A first higher refractive index structure doped to include regions having a first conductivity type, and a second higher refractive index structure doped to include regions having the first conductivity type, and

[0131] One or more gap regions between the first higher refractive index structure and the second higher refractive index structure, the gap regions having a lower refractive index than the first higher refractive index structure and the second higher refractive index structure;

[0132] A first support structure is configured to support the first higher refractive index structure and enable the first higher refractive index structure to move to change the size of at least one of the one or more gap regions, wherein the first support structure is doped to include a region having a second conductivity type different from the first conductivity type; and

[0133] A second support structure is configured to support the second higher refractive index structure and enable the second higher refractive index structure to move to change the size of at least one of the one or more gap regions, wherein the second support structure is doped to include regions having the second conductivity type.

Claims

1. An apparatus for modulating an optical wave, the apparatus comprising: a slit waveguide structure comprising: a first higher-index structure doped to include a region having a first conductivity type, a second higher-index structure doped to include a region having the first conductivity type, and one or more slit regions between the first higher-index structure and the second higher-index structure, the slit regions consisting essentially of a gas, liquid, or viscous material having a lower index of refraction than the first higher-index structure and the second higher-index structure; a first support structure configured to enable movement of the first higher-index structure to change a size of at least one of the one or more slit regions, wherein the first support structure is doped to include a region having a second conductivity type opposite the first conductivity type; and a second support structure configured to enable movement of the second higher-index structure to change the size of at least one of the one or more slit regions, wherein the second support structure is doped to include a region having the second conductivity type.

2. The apparatus of claim 1, wherein the slit waveguide structure comprises a multi-slit waveguide structure, wherein the one or more slit regions comprise two or more slit regions.

3. The apparatus of claim 2, wherein the slit waveguide structure further comprises: a third higher-index structure between the first higher-index structure and the second higher-index structure.

4. The apparatus of claim 3, wherein: the first support structure is configured to enable movement of the first higher-index structure to change a size of a slit region between the first higher-index structure and the third higher-index structure; and the second support structure is configured to enable movement of the second higher-index structure to change a size of a slit region between the second higher-index structure and the third higher-index structure.

5. The apparatus of claim 1, further comprising: an input-coupling structure configured to receive the optical wave and provide coupling between a spatial mode of the optical wave and a eigenmode of the slit waveguide structure; and an output-coupling structure configured to provide coupling between the eigenmode of the slit waveguide structure and a spatial mode of a modulated optical wave that has been modulated during propagation of the optical wave through the slit waveguide structure based at least in part on a change in size of at least one of the one or more slit regions.

6. The apparatus of claim 1, wherein the doped region of the first higher-index structure and the doped region of the second higher-index structure have substantially equal doping concentrations.

7. The apparatus of claim 6, wherein the doped region of the first support structure and the doped region of the second support structure have substantially equal doping concentrations.

8. The apparatus of claim 1, wherein the doped region of the first support structure is electrically coupled to a first electrode, and the doped region of the second support structure is electrically coupled to a second electrode.

9. The apparatus of claim 8, further comprising a voltage source configured to provide a voltage between the first electrode and the second electrode to cause movement that changes a size of at least one of the one or more slit regions.

10. The apparatus of claim 1, wherein the slit waveguide structure comprises a portion of an arm of an interferometric structure.

11. The apparatus of any one of claims 1 to 9, comprising an interferometric structure, wherein the slit waveguide structure is a portion of an arm of the interferometric structure.

12. The apparatus of claim 11, wherein the slit waveguide structure is configured to modulate a phase of an optical wave propagating in the arm of the interferometric structure.

13. The apparatus of claim 12, wherein the interferometric structure is configured to modulate an amplitude of the optical wave propagating in the interferometric structure.

14. The apparatus of claim 11, wherein the interferometric structure comprises a Mach-Zehnder interferometer.

15. The apparatus of any one of claims 1 to 10, wherein the first higher refractive index structure and the first support structure form an integrated structure, and / or the first support structure and the second support structure form an integrated structure.

16. The apparatus of claim 15, wherein the second higher refractive index structure and the second support structure form an integrated structure.

17. The apparatus of claim 16, wherein the first higher refractive index structure, the second higher refractive index structure, the first support structure, and the second support structure form an integrated structure.

18. The apparatus of any one of claims 1-10, wherein, The first support structure is configured to support the first higher refractive index structure, and the second support structure is configured to support the second higher refractive index structure.

19. An apparatus comprising: a slit waveguide structure comprising: two or more higher refractive index structures each doped to include a region having a first conductivity type, and one or more slit regions between the two or more higher refractive index structures having a lower refractive index than a refractive index of the two or more higher refractive index structures; and a support structure configured to support and enable movement of a corresponding higher refractive index structure to change a size of at least one of the one or more slit regions, wherein each support structure is doped to have a second conductivity type opposite the first conductivity type.

20. The apparatus of claim 19, comprising an electrode configured to enable an application of a voltage across a region in the higher refractive index structure doped to have a first conductivity type and a region in a corresponding support structure doped to have the second conductivity type.

21. A system comprising: a processor unit comprising: a light source configured to provide a plurality of light outputs; a plurality of optical modulators coupled to the light source and the first unit, the plurality of optical modulators configured to produce an optical input vector comprising a plurality of optical signals by modulating the plurality of optical outputs provided by the light source based on a plurality of modulator control signals; and a matrix multiplication unit coupled to the plurality of optical modulators, the matrix multiplication unit configured to convert the optical input vector to an output vector based on a plurality of weight control signals; wherein at least one of the optical modulators comprises the apparatus of any one of claims 1 to 10.

22. The system of claim 21, wherein each of the optical modulators comprises the apparatus of any one of claims 1 to 10.

23. An optical processor comprising a plurality of optical modulators, wherein at least one of the optical modulators comprises the apparatus of any one of claims 1 to 10.

24. The optical processor of claim 23, wherein each of the plurality of optical modulators comprises the apparatus of any one of claims 1 to 10.

25. A system comprising at least one of a robot, an autonomous vehicle, an autonomous drone, a medical diagnostic system, a fraud detection system, a weather forecasting system, a financial forecasting system, a facial recognition system, a voice recognition system, or a product defect detection system, wherein at least one of the robot, the autonomous vehicle, the autonomous drone, the medical diagnostic system, the fraud detection system, the weather forecasting system, the financial forecasting system, the facial recognition system, the voice recognition system, or the product defect detection system comprises the apparatus of any one of claims 1 to 10.

26. A method for fabricating an optical modulator, the method comprising: forming a slot waveguide structure comprising: a first higher refractive index structure, a second higher refractive index structure, and one or more slot regions between the first higher refractive index structure and the second higher refractive index structure, the slot regions consisting essentially of a gas, liquid, or viscous material having a lower refractive index than the first higher refractive index structure and the second higher refractive index structure; forming a first support structure configured to support the first higher refractive index structure and enable movement of the first higher refractive index structure to change a size of at least one of the one or more slot regions; forming a second support structure configured to support the second higher refractive index structure and enable movement of the second higher refractive index structure to change a size of at least one of the one or more slot regions; doping the first higher refractive index structure to include a region having a first conductivity type; doping the second higher refractive index structure to include a region having the first conductivity type; doping the first support structure to include a region having a second conductivity type opposite the first conductivity type; and doping the second support structure to include a region having the second conductivity type.

27. The method of claim 26, wherein forming the slit waveguide structure comprises: forming a plurality of holes within a portion of the first support structure, forming a plurality of holes within a portion of the second support structure, and providing a gas through at least some of the plurality of holes to etch a portion of the material forming the first higher refractive index structure and the second higher refractive index structure to enable movement of the first higher refractive index structure and the second higher refractive index structure.

28. The method of claim 27, wherein the doping of the first higher refractive index structure, the second higher refractive index structure, the first support structure, and the second support structure occurs before the plurality of holes are formed within portions of the first and second support structures.

29. A method of modulating an optical wave, the method comprising: propagating an optical wave along a slot waveguide structure, the slot waveguide structure comprising: two or more suspended waveguide core structures defining one or more slot regions between the suspended waveguide core structures; and modulating the optical wave by generating electromagnetic forces to move the two or more suspended waveguide core structures and modify a size of the one or more slot regions between the suspended waveguide core structures and modify an effective refractive index of the slot waveguide structure.

30. The method of claim 29, wherein the slot waveguide structure comprises support structures, each support structure configured to generate the electromagnetic forces including repulsive forces to move a suspended waveguide core structure away from a corresponding support structure.

31. The method of claim 29, wherein the slot waveguide structure comprises support structures, each support structure configured to generate the electromagnetic forces including attractive forces to move a suspended waveguide core structure toward a corresponding support structure.

32. The method of any of claims 29 to 31, wherein each suspended waveguide core structure comprises a region doped to have a first conductivity type, and the corresponding support structure comprises a region doped to have a second conductivity type opposite the first conductivity type.

33. An apparatus comprising: a slot waveguide structure comprising: a first higher refractive index structure doped to include a region having a first conductivity type, a second higher refractive index structure doped to include a region having the first conductivity type, and one or more slot regions between the first higher refractive index structure and the second higher refractive index structure, the slot regions having a lower refractive index than the first higher refractive index structure and the second higher refractive index structure; a first support structure configured to support the first higher refractive index structure and enable movement of the first higher refractive index structure to change a size of at least one of the one or more slot regions, wherein the first support structure is doped to include a region having a second conductivity type different from the first conductivity type; and a second support structure configured to support the second higher refractive index structure and enable movement of the second higher refractive index structure to change a size of at least one of the one or more slot regions, wherein the second support structure is doped to include a region having the second conductivity type. a second support structure configured to support the second higher refractive index structure and enable movement of the second higher refractive index structure to change a size of at least one of the one or more aperture regions, wherein the second support structure is doped to include a region having the second conductivity type.

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