Mixed metal oxide semiconductor capacitor with enhanced phase tuning

Abstract

The present disclosure relates to hybrid metal-oxide semiconductor capacitors with enhanced phase tuning, the disclosed embodiments improve the efficiency of phase tuning for optical devices such as hybrid semiconductor-on-metal capacitors (MOSCAPs) III-V / Si micro-ring lasers. The present disclosure integrates silicon devices into the waveguide structure of the optical devices disclosed herein, for example, waveguide resistor heaters, waveguide PIN diodes, and waveguide PN diodes. In some examples, these optical devices are MOSCAPs formed by a dielectric layer between two semiconductor layers, which achieve a small phase tuning via plasma dispersion and / or carrier dispersion effects that occur depending on the polarity of the bias voltage. According to the embodiments disclosed herein, the plasma dispersion and / or carrier dispersion effects are enhanced by heating, carrier injection, and / or additional plasma dispersion based on the disclosed silicon devices integrated into the waveguide.

Description

Technical Field

[0001] The present disclosure relates to the field of light modulation, and in particular to an optical device and a microring laser. Background Art

[0002] In an optical transmitter, an optical modulator is used to modulate an optical carrier (light beam) with an analog or digital signal for transmission through an optical fiber. A typical wavelength-division multiplexing-based optical transmitter uses several lasers, each operating at a different wavelength, to generate several different optical carriers. Each carrier passes through its own optical modulator, where it is modulated with the signal to be transmitted. The modulated carrier is then fed into the optical fiber through an optical multiplexer for transmission. An example silicon-based optical modulator design includes a metal oxide semiconductor (MOS) capacitor adjacent to a silicon optical waveguide. A signal applied to the capacitor induces charge accumulation near the center of the capacitor. This charge accumulation modifies the refractive index of the optical waveguide and its propagation loss. Modifying the refractive index causes a phase shift in the light beam propagating through the waveguide, thereby phase modulating the light. When phase shifting is used in an optical waveguide component such as a Mach-Zehnder interferometer (MZI), a ring resonator, or a Fabry-Perot (FP) resonator, the optical waveguide component converts the optical phase shift into a change in optical power to achieve optical intensity modulation. When the goal is to reduce analog optical power or constant optical power, instead of encoding an electrical signal into an optical signal, the optical modulator can be used as an optical attenuator. Summary of the Invention

[0003] Provided is an optical device, comprising: a substrate; a heterogeneous metal oxide semiconductor (MOS) capacitor formed on the substrate, the heterogeneous MOS capacitor comprising: an optical waveguide; a first cathode comprising a first material and formed in the optical waveguide; an anode formed in the optical waveguide, the anode comprising a second material different from the first material; and a dielectric disposed between the first cathode and the anode, the dielectric comprising an oxide of the first material and an oxide of the second material, wherein the heterogeneous MOS capacitor is defined between the anode and the first cathode; and a semiconductor device layer disposed between the substrate and the heterogeneous MOS capacitor and formed in the optical waveguide. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] According to one or more various embodiments, the present disclosure is described in detail with reference to the following drawings. The drawings are provided for illustration purposes only and depict only typical or example embodiments.

[0005] Figure 1A and Figure 1B An example hybrid metal oxide semiconductor (MOS) ring resonator optical modulator is illustrated.

[0006] Figure 1C shows that for various cathode materials, applied to Figure 1A and Figure 1B Simulated relationship between the voltage of the optical modulator and the mode refractive index change and FCA change.

[0007] Figure 2 Illustrated are example optical devices according to implementations disclosed herein.

[0008] Figure 3 Illustrated is a top view of an example optical device according to implementations disclosed herein.

[0009] Figure 4 An example optical device with an integrated resistor element according to embodiments disclosed herein is illustrated.

[0010] Figure 5 An example optical device integrated with a positive intrinsic negative (PIN) junction diode element according to embodiments disclosed herein is illustrated.

[0011] Figure 6 An example optical device integrating a positive-negative (PN) junction diode element according to embodiments disclosed herein is illustrated.

[0012] Figure 7 is a schematic diagram of an example optical device according to embodiments disclosed herein.

[0013] Figure 8 is an example computer system that can be used to implement various features of the various optical devices of the present disclosure.

[0014] The drawings are not exhaustive and do not limit the disclosure to the precise forms disclosed. DETAILED DESCRIPTION

[0015] Various examples disclosed herein provide optical modulators that utilize heterogeneous MOS capacitors (MOSCAPs) adjacent to optical waveguides. Charge accumulation and / or depletion can be induced within the MOSCAP by applying a bias voltage. Accumulation and / or depletion modifies the refractive index of the optical waveguide and causes a phase shift in a light beam propagating through the optical waveguide, thereby phase modulating the light beam. However, the phase shift induced in conventional MOSCAP design is weak and inefficient. For example, the phase shift is weak because it is based on carrier accumulation or carrier depletion, meaning that the phase shift depends on the presence or absence of carriers, which may be weak.

[0016] Accordingly, examples herein provide enhanced phase shift properties and, therefore, improved phase modulation efficiency. For example, embodiments herein provide an optical device having a thin interfacial oxide (e.g., a dielectric material) sandwiched between two dissimilar semiconductors (e.g., a cathode and an anode), thereby forming a heterogeneous MOSCAP (referred to herein as a heterogeneous or hybrid MOSCAP). In various examples, the dissimilar semiconductors include a first semiconductor comprising a III-V material and a second semiconductor comprising silicon, other IV materials (e.g., germanium, silicon carbide, silicon germanium, etc.), or any semiconductor material capable of both electrical conductivity and optical transparency. The two semiconductors can be formed in an optical waveguide and on opposite sides of the optical waveguide.

[0017] By changing the free carrier density, charge depletion or accumulation within the capacitor (e.g., within the optical waveguide) changes the local refractive index of the optical waveguide. According to embodiments disclosed herein, this effect is enhanced by integrating semiconductor devices (such as resistor elements, PIN junction diodes, or PN junction diodes) into the optical waveguide combined with the MOSCAP. In some examples, the optical device disclosed herein also integrates a light-emitting component into the optical device. The light-emitting component (such as a laser or other light-emitting diode) can be formed on the MOSCAP and adapted to generate light that can be injected into the optical waveguide. The injected light can then be phase-shifted and modulated based on the change in the local refractive index of the waveguide caused by the charge accumulation and / or depletion within the MOSCAP.

[0018] Accordingly, the present disclosure provides various configurations for improving the phase tuning efficiency of hybrid MOSCAP microring lasers. The improved phase tuning efficiency results in a wider wavelength shift, which can be used for direct high-speed modulation and / or alignment of resonator-based modulators. The MOSCAP structure, formed by a thin dielectric layer between two semiconductor layers, results in small phase tuning via plasma dispersion or carrier dispersion effects that occur depending on the bias polarity. This phase tuning can be enhanced by heating, carrier injection, or additional plasma dispersion achieved by independently and simultaneously applying a bias to an integrated silicon device, for example, implemented as one of a resistor element, a PN junction diode, and a PIN junction diode integrated into an optical waveguide.

[0019] Accordingly, the embodiments disclosed herein provide structures that improve the phase shifter efficiency of state-of-the-art micro-ring lasers and / or optical modulators. Additionally, the embodiments herein utilize multiple individual electrical contacts (also referred to herein as electrodes) that can be independently biased (e.g., by independently biasing each electrical node) to achieve not only a wider phase shift range but also more complex functionality of tuning capabilities.

[0020] For example, the optical devices disclosed herein can enhance the phase shifting and modulation used by dense wavelength division multiplexing (DWDM) photonic integrated circuits (PICs) that implement DWDM systems, such as transceivers. Dense wavelength division multiplexing (DWDM) is an optical multiplexing technology used to increase bandwidth on existing fiber optic networks. The DWDM PIC architecture includes photonic devices fully integrated on a single manufacturing platform. By using the embodiments disclosed herein that provide improved phase shifting and modulation efficiency, many optical devices on the PIC can be implemented with higher performance and a smaller footprint.

[0021] It should be noted that, as used herein, the terms "optimize," "optimize," "improve," "enhance," and the like may be used to mean achieving or realizing as efficient or perfect a performance as possible. However, one of ordinary skill in the art reading this document will recognize that perfection is not always achievable. Thus, these terms may also encompass achieving or realizing the best possible, efficient, or practical performance under given circumstances, or achieving or realizing performance that is superior to that achievable using other settings or parameters.

[0022] Figure 1A and Figure 1B An example hybrid MOS ring resonator optical modulator 100 is illustrated. Figure 1A is a perspective view of the light modulator 100, and Figure 1B The hybrid MOS optical modulator 100 is along Figure 1A A cross-sectional view taken along line AA' shown in FIG.

[0023] The optical modulator 100 includes an optical waveguide 102, a cathode 104 made of a first material and formed in the optical waveguide 102, and an anode 106 made of a second material different from the first material and formed in the optical waveguide 102. The anode and the cathode are adjacent to each other, and a capacitor is defined between the anode and the cathode.

[0024] In some examples, substrate 101 includes an oxide grown on an underlying layer 108. A silicon layer 110 is formed on substrate 101. A trench 112 separates optical modulator 100 into two portions 114 and 116. First portion 114 includes anode 106. Optical waveguide 102 is formed in anode 106. Cathode 104 is integrated into second portion 116. In various embodiments, cathode 104 includes a layer of a III-V material as a first material. MOS capacitor 124 is defined between cathode 104 and anode 106.

[0025] Dielectric 118 is formed between cathode 104 and anode 106. Dielectric 118 can be an electrically insulating material formed between cathode 104 and anode 106 of MOS capacitor 124, and polarizing dielectric 118 by an applied electric field can increase the surface charge of MOS capacitor 224 at a given electric field strength. Dielectric 118 can be a native oxide of the cathode or anode or both, or an external dielectric material such as a high-k dielectric or polymer that can be formed by deposition, oxidation, wafer bonding, or other dielectric coating methods.

[0026] Cathode 104 may comprise negatively doped silicon, while anode 106 may comprise positively doped silicon. Cathode electrode 120 is disposed on cathode 104, while anode electrode 122 is disposed on anode 106. When a voltage is applied between these electrodes, carrier accumulation, depletion, or inversion may occur around dielectric 118. Because the capacitor region overlaps the optical waveguide, changes in carrier concentration may cause changes in the refractive index and propagation loss of the waveguide mode. By biasing the voltage applied between these electrodes, the refractive index may be modulated accordingly, thereby inducing optical intensity modulation, phase shift modulation, and attenuation.

[0027] Light can be input into bus waveguide 105, with a portion of the light being tapped into optical waveguide 102 (e.g., at least a portion of the light propagating in bus waveguide 104 is transferred into optical waveguide 102). The light propagating through optical waveguide 102 is modulated, attenuated, and phase-shifted based on a change in the refractive index of the waveguide mode induced by applying a bias voltage to MOS capacitor 124. A portion of the modulated and attenuated light can then exit optical waveguide 102 and be coupled into bus waveguide 105, and output from optical modulator 100 for downstream use.

[0028] For example, Figure 1B A DC power supply 126 is included. The DC power supply 126 acts as a signal source and has a negative terminal connected to the cathode electrode 120 and a positive terminal connected to the anode electrode 122. This causes negative charge to migrate from the cathode 104 toward the side of the optical waveguide 102 adjacent to the cathode 104, and positive charge ("holes") to migrate from the anode 106 to the opposite side of the waveguide 102 (also referred to herein as an accumulation mode). In other examples, the polarity of the DC power supply 126 can be reversed. Reversing the polarity of the DC power supply 126 causes negative charge to migrate from the waveguide 102 toward the cathode electrode 120, and holes to migrate from the waveguide 102 toward the anode electrode 122 (also referred to herein as a depletion mode).

[0029] MOS capacitor 124 is formed at the boundary between the III-V material of cathode 104 and the underlying capacitor portion of intrinsic silicon or other IV material. A thin layer of silicon and III-V oxide (e.g., dielectric 118) naturally forms at this boundary and serves as the dielectric of the capacitor. In some examples, this thin layer has a thickness on the nanometer scale, for example, a few nanometers thick. In some examples, no steps need to be taken to encourage the formation of dielectric 118. In other examples, the formation of dielectric 118 can be stimulated, for example, by increasing the temperature, exposing the material to an oxygen-rich atmosphere, or other suitable techniques.

[0030] In some examples, the III-V material may include indium phosphide (InP). In other examples, the III-V material may include gallium arsenide (GaAs) or other compounds of indium, gallium, phosphorus, and arsenic. More typically, the cathode and anode are formed of different materials, which may include II-VI semiconductor compounds or other materials. Metals may also be used.

[0031] As previously discussed, MOS capacitor 124 is formed inside optical waveguide 102 such that charge carriers accumulated / depleted on both sides of the capacitor dielectric have the effect of changing the refractive index and waveguide loss (e.g., loss or attenuation of propagating signal power in the waveform) of the optical waveguide.

[0032] The MOS capacitor 124 can operate in accumulation, depletion, or inversion modes (e.g., accumulating electrons at the dielectric layer in addition to the presence of holes). As discussed above, a DC voltage can be applied between the anode and cathode to cause a thin charge layer to accumulate, deplete, or invert on both sides of the dielectric layer 118. The resulting change in the free carrier density causes a change in the refractive index n of the optical waveguide 102, which manifests as a change in the effective refractive index (Δn) of the optical mode. eff The change in effective refractive index or the modulation (Δn ) can be described as follows eff ) and the associated change in optical loss (Δα):

[0033]

[0034] Where q is the charge applied to the cathode 104 and anode 106, c is the speed of light in a vacuum, ε0 is the dielectric constant of free space, n is the material refractive index, and ΔN represents the change in carrier density such that ΔN e Indicates the change in the carrier density of electrons, ΔN h represents the change in carrier density of holes, and m* represents the change in electrons (m* ce ) and holes (m* ch )'s relative effective mass, μ h represents the hole mobility, μ erepresents the electron mobility, and λ0 is the free-space wavelength.

[0035] The optical phase shift at the ends of the capacitor Depends on voltage-induced Δn eff , the device length L, and the magnitude of the optical wavelength λ. In this example, the optical phase shift can be calculated as Therefore, the optical phase of light within the optical waveguide 102 can be determined based on the voltage-induced Δn eff In various examples, the waveguide loss of silicon and III-V materials can also change with carrier density, and controlling the change in waveguide loss can be used as an optical attenuator. For example, the change in waveguide loss can be controlled based on carrier density, which can result in attenuation of the waveguide loss. The attenuated waveguide loss can then be used to modulate the signal.

[0036] As in Figure 1A As shown in FIG, the optical modulator 100 may be a ring resonator optical modulator. In this case, Figure 1B The trench 112 shown in FIG. 1 is provided as an annular trench that divides the optical modulator into a first portion 114 and a second portion 116, respectively. Similarly, the anode 106 is provided as an annular anode in the second portion, and the cathode 104, dielectric 118, and silicon layer 116 are cylindrical in the first portion. A MOS capacitor 124 is defined across the boundary between the cathode and the anode.

[0037] Figure 1C shows that for various cathode materials, applied to Figure 1A and Figure 1B Figure 1 shows the simulated relationship between the voltage of the optical modulator 100 and the optical mode refractive index change (Δneff) (left axis) and free carrier absorption (FCA) change (right axis) of the waveguide. As indicated by pointer 130, the solid line shows the refractive index change (Δneff) for each material (e.g., Si, InP, and GaAs). Similarly, the dotted line indicated by pointer 140 shows the FCA change for each material (e.g., Si, InP, and GaAs).

[0038] Used to generate Figure 1C The example light modulator includes a cathode 106 formed of one of Si, InP, or GaAS with a thickness of 150 nm, as shown in Figure 1C The dielectric layer 118 has a thickness of 15 nm and is formed of aluminum dioxide (Al2O2). The anode 104 is formed of Si. The thickness of the anode 104 portion forming the waveguide 102 is 800 nm wide and 250 nm thick. This is used to generate the Figure 1CExample configuration of simulated data in . Other configurations are also contemplated.

[0039] As described above, depletion or accumulation of charge at the interface layer can cause a change in the free carrier density that will change the local refractive index of the waveguide 102. Figure 1C As shown in , in conventional systems, this effect is weak, slow, and inefficient. For example, Figure 1C A slight change in the refractive index (Δneff) along the left y-axis is shown. Figures 4 to 6 As described, embodiments disclosed herein enhance changes in refractive index. Accordingly, examples disclosed herein improve this effect by, for example, increasing the amount of change per applied voltage and / or reducing the amount of time between the applied voltage and the induced change to improve the optical phase shift induced by the MOS capacitor. Embodiments disclosed herein combine a MOS capacitor modulator with a silicon device integrated into an optical waveguide, the silicon device being configured to improve the efficiency of the optical phase shift by, for example, increasing the change in carrier concentration in the waveguide by integrating a resistor element, a PIN junction diode, and / or a PN junction diode into the optical waveguide.

[0040] Figure 2 An example optical device according to embodiments disclosed herein is illustrated. Embodiments herein are described as MOS capacitor (MOSCAP) lasers, and more particularly, as microlasers including hybrid MOS optical modulators. Optical device 200 may be Figure 3 Representation of a cross section of the optical device 300 taken along line BB′.

[0041] The optical device 200 includes an optical waveguide 202, a first cathode 204 including a first material and having a portion formed in the optical waveguide 202, and an anode 206 including a second material different from the first material and formed in the optical waveguide 202. The anode 206 is adjacent to the cathode 204 within the waveguide 202. A capacitor 224 is defined between the anode 206 and the cathode 204.

[0042] In various examples, a box layer 201 comprising an oxide, for example, a different oxide such as a silicon dioxide layer, is grown on a substrate 208. Additionally, a silicon device layer 210 and an anode 206 are formed on the box layer 201. A cathode 204 is formed above the silicon device layer 210 opposite the box layer 201 and spans a trench 212 formed between the silicon device layer 240 and the capacitor 224. In various embodiments, the cathode 204 comprises a layer of a Group III-V material as a first material, such as indium phosphide (InP), gallium arsenide (GaAs), or other compounds of indium, gallium, phosphorus, and arsenic. The cathode 204 can be formed by deposition, wafer bonding, monolithic growth, or other fabrication techniques. The anode 206 can comprise silicon or another Group IV material as a second material, such as germanium, silicon carbide, silicon germanium, or the like. The capacitor 224 can be a MOSCAP defined between the cathode 204 and the anode 206.

[0043] A dielectric 218 (also referred to herein as an interfacial layer) is formed between the cathode 204 and the anode 202 and in the waveguide 202. The dielectric 218 can be a native oxide of the cathode or anode or both, or an external dielectric material such as a high-k dielectric or a polymer that can be formed by deposition, oxidation, wafer bonding, or other dielectric coating methods.

[0044] MOSCAP 224 is formed at the boundary between the first material of cathode 204 and the underlying optical waveguide of semiconductor material (e.g., silicon or other Group IV material). A thin layer of silicon and III-V oxide (e.g., dielectric 218) forms at this boundary and serves as the dielectric of the capacitor. In some examples, dielectric layer 218 can have a nanometer-scale thickness, for example, dielectric layer 218 can be a few nanometers thick. In some examples, no steps need to be taken to encourage the formation of dielectric 218. In other examples, the formation of dielectric 218 can be stimulated, for example, by increasing the temperature, exposing the material to an oxygen-rich atmosphere, or other suitable techniques.

[0045] The cathode 204 may include negatively doped silicon (e.g., an n-doped semiconductor layer), and the anode 206 may include a positively doped material (e.g., a p-doped semiconductor layer). In some embodiments, the anode 206 includes a heavily positively doped material, e.g., including a greater carrier concentration (e.g., holes or electrons) than the carrier concentration of the cathode 204. In an example, the anode 206 may include a material doped to approximately 1e20 cm -3 In some examples, the silicon device layer 210 may include a heavily doped material. For example, the silicon device layer 210 may include a material doped to approximately 1e20 cm -3204. A contact electrode 220 (also referred to as electrode 220) is disposed on the cathode 204, and a contact electrode 222 (also referred to as electrode 222) is disposed on the anode 206. When a voltage bias is applied to the electrodes 220 and 222, carrier accumulation, depletion, or inversion may occur around the dielectric 220, as described in more detail below. Because the capacitor region overlaps the optical waveguide, changes in carrier concentration may cause changes in the waveguide mode refractive index and propagation loss. By biasing the voltage applied between the electrodes 220 and 222, the refractive index may be modulated accordingly, thereby inducing optical intensity modulation, attenuation, and optical mode phase shift (e.g., shifting the wavelength carried by the waveguide 202).

[0046] The optical waveguide 202 (e.g., orthogonal to the optical waveguide 202) is propagated based on the change in the refractive index of the waveguide mode induced by applying a bias voltage to the MOSCAP 224. Figure 2 ) is modulated, attenuated, and phase-shifted. A portion of the modulated and attenuated light can then exit the optical waveguide 202 via the channel between the groove 212 and the box layer 201, be connected to the bus waveguide 205, and be output from the optical device 200 for downstream use. The box layer 201 can be provided to confine the optical mode in the vertical direction (e.g., into a layer provided on the box layer 201).

[0047] As discussed above, a MOS capacitor is formed inside the optical waveguide 202 such that charge carriers accumulated / depleted on both sides of the capacitor dielectric have the effect of changing the refractive index of the waveguide and changing the propagation losses.

[0048] MOS capacitors can be operated in accumulation, depletion, or inversion modes. As discussed above, a DC voltage can be applied between the anode 206 and cathode 204, causing a thin charge layer to accumulate, deplete, or invert on either side of the dielectric layer 218. The resulting change in the free carrier density causes a change in the refractive index n of the waveguide 202, which manifests as a change in the effective refractive index (Δn) of the optical mode. eff ). According to the above explanation in equations 1 and 2, the change or modulation amount of the effective refractive index (Δn eff ) and the associated change in optical loss (Δα). Voltage-induced Δn eff An optical phase shift of the light propagating in the optical waveguide 202 is also induced, as discussed above.

[0049] To enhance the change in effective refractive index and the optical phase shift induced in optical waveguide 202, a silicon device layer 210 is formed on box layer 201 and in waveguide 202. Silicon device layer 210 includes an anode 206 and a second cathode 240, which comprises a third material and is formed in bus waveguide 205. The third material can be silicon or another Group IV material, which can be the same as or different from the material of cathode 204. Second cathode 240 is also formed in optical waveguide 202, thereby providing a channel through which a portion of light passing through waveguide 202 can be coupled to bus waveguide 205. Second cathode 240 is formed in silicon device layer 210 and overlaps trench 212.

[0050] As described above, the change in the effective refractive index of the mode and the phase shift induced by the voltage bias applied to the MOS capacitor are small and are enhanced by the embodiments disclosed herein through the use of the silicon device layer 210. For example, as described above, the embodiments disclosed herein improve the phase tuning efficiency, which translates into a wider wavelength shift that can be used for direct high-speed modulation and / or alignment of a resonator-based modulator. For example, the second cathode 240 can include a doped material that can be a positively doped material or a negatively doped material (e.g., an n-doped semiconductor layer or a p-doped semiconductor layer), and the optical waveguide 202 can include an intrinsically doped material or a positively doped material and / or a negatively doped material (e.g., an n-doped semiconductor layer or a p-doped semiconductor layer). The second cathode 240 can be a heavily doped material of either polarity (e.g., 210 can include a heavily doped material doped to approximately 1e20 cm -3 MOSCAP 224 is disposed on cathode 240. When a voltage bias is applied between electrodes 234 and 222, carrier accumulation, depletion, or inversion can be enhanced within optical waveguide 202 based on the dopant material of silicon device layer 210, as described in more detail below. Due to the silicon device layer 210 formed within optical waveguide 202, carrier concentration changes can enhance the changes in waveguide mode refractive index and propagation loss induced by applying a bias to MOSCAP 224.

[0051] In various examples, dielectric 218 is formed between cathode 240 and cathode 204. Figure 2 , the dielectric 218 is formed continuously from the cathode 204 to the optical waveguide 202 so as to overlap with the trench 212. In another example, the dielectric 218 may not exist in the trench 212. In this case, two dielectrics 218 may be formed, namely, a first dielectric between the optical waveguide 202 and the cathode 204 and a second dielectric between the cathode 240 and the cathode 204.

[0052] Additionally, in various examples, the optical device 200 includes an optional light-emitting portion configured to generate light that is injected into the optical waveguide 202. The light generated by the light-emitting portion can be modulated based on the bias applied to the MOSCAP 224 and the second cathode 240, and a portion of the modulated light can be tapped into the bus waveguide 205. In the event that the light-emitting portion is not included in the optical device 200, light can be received from the bus waveguide 205 and tapped into the optical waveguide 202, as described above. The tapped light can then be modulated based on the bias applied to the MOSCAP 224 and the second cathode 240, and then output into the bus waveguide 205.

[0053] The light emitting part can be a light emitting diode, a laser diode, etc. Figure 2 In the illustrative example shown in , the optical device 200 includes an optical gain material 232 (or laser gain material in the case of a laser diode) formed on the cathode 204. For example, the optical gain material 232 may include quantum dots (QDs) or quantum wells (QWs). A doped semiconductor layer 230 is formed between the optical gain material 232 and the highly doped semiconductor layer 228. The semiconductor layers 230 and 228 may include silicon or another Group IV material. In various examples disclosed herein, where dopants are added on the order of one dopant atom per 100 million atoms, the material may be referred to as low-doped or lightly doped. However, where more dopant atoms are added, such as on the order of one part per ten thousand atoms, the material may be referred to as highly doped. In one illustrative example, the semiconductor layer 230 may be at a density of 5e17 cm -3 and 5e18cm -3 The semiconductor layer 230 may be doped between 5e17cm -3 and 5e18cm -3 The silicon device layer 210 and the anode 206 may be doped to about 1e20cm -3 , and the highly doped semiconductor layer 228 can be 5e18cm -3 and 5e19cm -3 Mixed in between.

[0054] Doped semiconductor layer 230 may include positively doped silicon (e.g., a p-doped semiconductor layer), and highly doped semiconductor layer 228 may include positively doped silicon (e.g., a highly p-doped semiconductor layer). Electrode 226 may be formed on highly doped semiconductor layer 228, opposite to doped semiconductor layer 230. When a voltage bias is applied between electrode 226 and electrode 220, the change in carrier concentration causes stimulated emission in optical gain material 230, thereby generating light. The generated light travels through the layers and is received at waveguide 202, where it is modulated according to the bias voltages of the MOSCAP and silicon device layer 210. A portion of the modulated light is coupled into waveguide 205 for downstream use. Controlling the width of trench 212 modulates the amount of light from optical waveguide 202 that is injected into waveguide 205 (e.g., a larger width results in a smaller percentage of light being injected into the waveguide).

[0055] Accordingly, by biasing the voltage applied between electrode 226 and electrode 220, light emission is generated by optical device 200 and injected into optical waveguide 202. The light can then be modulated and attenuated by varying the refractive index of optical waveguide 202 by biasing the voltage applied to the capacitor region, which can be enhanced by biasing the silicon device layer region. For example, by employing phase shifting and modulation via separate electrical contacts (e.g., applying a voltage bias between electrode 220 and electrode 222 while simultaneously applying a bias between electrode 234 and electrode 222), embodiments herein can achieve not only non-return-to-zero (NRZ) modulation with a large optical modulation amplitude (OMA) using two synchronized NRZ electrical signals, but also pulse amplitude modulation (e.g., PAM4) using two separate NRZ electrical signals. For example, independently biasing the voltage applied to each pair of electrode contacts allows for separate modulation. As an illustrative example, MOSCAP 224 and second cathode 240 can be independently biased to induce modulation of the phase shift property. Furthermore, the biasing of the light emitting portion can permit modulation of the amplitude of the output light along with modulation of the phase shift. As an illustrative example, by applying a voltage bias across electrodes 226 and 220 of the light emitting portion to induce amplitude modulation of the light (e.g., causing the light intensity to vary), MOSCAP 224 and second cathode 240 are also biased to induce phase shift modulation.

[0056] Although Figure 2The optical device 200 is illustrated as including a light emitting portion, but the present disclosure is not so limited. For example, the optical device 200 need not include a light emitting portion and can receive light from an external source, for example, similar to the light modulator 100 described above. Additionally, while certain materials are described as being negatively doped or positively doped, embodiments are not limited thereto, and the polarity doping can be switched. For example, while the above examples describe the cathode 204 as negatively doped and the anode 206, layer 230, and layer 228 as positively doped, the polarity of each layer can be switched such that the cathode 204 is positively doped and the anode 206, layer 230, and layer 228 can be negatively doped.

[0057] Figure 3 Illustrated is a top view of an example optical device according to implementations disclosed herein. Figure 3 The optical device 300 illustrates a micro laser including a hybrid MOS optical modulator having a ring structure, for example, a micro-ring laser including a hybrid MOS optical modulator (generally referred to herein as a MOSCAP micro-ring laser or simply a MOSCAP laser). In the illustrative example, the optical device 300 is an example of the optical device 200 including a ring or annular structure when viewed from above. For example, Figure 2 The optical device 200 may be a representation of a cross section of the optical device 300 taken along line BB'. Accordingly, Figure 3 The reference numerals in the Figure 2 For example, Figure 3 Reference numeral 302 in the figure may correspond to Figure 2 The optical waveguide 202, reference numeral 305 may correspond to the bus waveguide 205 and so on. Thus, Figure 3 The elements and structures include the above combined Figure 2 The properties and characteristics described herein, except as herein referred to Figure 3 As explained.

[0058] Optical device 300 is formed on box layer 301, and silicon device layer 310 is formed on the box layer. An annular cathode 304 is formed on top of silicon device layer 310 and spans a trench (not shown), with a thin dielectric (e.g., similar to dielectric 218) (not shown) between the annular cathode and the silicon device layer. Silicon device layer 310 is formed within bus waveguide 305 and optical waveguide 302. Silicon device layer 310 includes a cylindrical anode 306, an annular optical waveguide 302, and an annular cathode 340. Cylindrical anode 306, with electrode 322 formed thereon, is surrounded by annular optical waveguide 302 and annular cathode 340. Waveguide 305 is formed within cathode 340. A MOS capacitor is defined between cathode 304 and anode 306 using the dielectric formed between cathode 304 and anode 306.

[0059] exist Figure 3 In the illustrative example of FIG, cylindrical electrode 322 is formed on anode 306; electrodes 320a and 320b (collectively referred to as electrodes 320) are formed on cathode 304; and electrodes 334a and 334b ​​(collectively referred to as electrodes 334) are formed on cathode 340. Cathode 304 may include electrode 320a, electrode 320b, or both, as desired. Each electrode 320 may be partially annular and may partially surround anode 306. In another example, electrodes 320 may be integrated into a single electrode 320 having an annular shape that surrounds anode 306. Similarly, cathode 340 may include electrode 334a, electrode 334b, or both, as desired. Each electrode 334 may be partially annular and may partially surround anode 306. In another example, electrodes 334 may be integrated into a single electrode 334 having an annular shape that surrounds anode 306.

[0060] Additionally, similar to optical device 200, optical device 300 includes a light emitting portion formed of a ring-shaped optical gain material, which is located below electrode 326 surrounding anode 306. A doped semiconductor layer is formed between the optical gain material and a highly doped semiconductor layer, which is located below electrode 326, as shown in FIG. Figure 2 described.

[0061] In operation, light propagates in a circular direction around the ring resonator in the optical waveguide 302. A portion of the light then exits the optical waveguide 302 and is coupled into the bus waveguide 305, and then output to downstream devices.

[0062] As mentioned above, the modulation and attenuation that occurs due to biasing the voltage applied to the capacitor region can be enhanced by including a silicon device layer (e.g., silicon device layer 210 and / or silicon device layer 310) formed in an optical waveguide (e.g., waveguide 202 and / or waveguide 302) as described herein. More specifically, the silicon device layer according to embodiments herein can be doped to induce a change in carrier concentration in the waveguide in response to an applied voltage. For example, referring to Figure 2 , the silicon device layer 210 may include a heavily positive doped material (e.g., silicon, etc.) that integrates a resistor element into the optical waveguide 202 (or 302). As another example, the silicon device layer 210 may include a heavily negative doped material (e.g., silicon, etc.) that integrates a positive-intrinsic-negative (PIN) junction diode element into the optical waveguide 202 (or 302), wherein the optical waveguide is an intrinsically doped region. In yet another example, the silicon device layer 210 may include a first region of heavily negative doped material (e.g., silicon, etc.) that integrates a positive-negative (PN) junction diode element into the optical waveguide 202 (or 302) and a second region of negative doped material (e.g., silicon, etc.). Referring to Figures 4 to 6Further details are provided regarding each embodiment.

[0063] Figure 4 An example optical device 400 is illustrated according to implementations disclosed herein. Figure 4 Shown with Figure 2 The optical device 200 and / or Figure 3 The optical device 300 is similar to or identical to the optical device 400, such that Figure 4 Similar reference numerals in Figure 2 Thus, like the optical devices 200 and 300, the optical device 400 includes the optical components described above in conjunction with Figure 2 and Figure 3 The capacitor region and optical light emitting portion are illustrated.

[0064] Additionally, the optical device 400 includes a silicon device layer 410 similar to the silicon device layer 210 of the optical device 200, except that the optical waveguide 402 is integrated with a resistor element. For example, the silicon device layer 410 may be substantially similar to Figure 2 The silicon device layer 210 is similar to the silicon device layer 210, except that the cathode 440 includes a heavily positively doped material such as silicon or other Group IV material. Additionally, the waveguide 402 includes an intrinsically doped material (e.g., silicon or other Group IV material) between the cathode 440 and the anode 206 and in contact with the cathode and the anode. In this embodiment, as described above, the anode 206 includes a heavily positively doped material. Accordingly, changes in carrier concentration in the waveguide 402 cause a high resistance region to generate heat based on the flow of charge passing between the highly doped contacts to the waveguide 402. Therefore, a resistor element is integrated into the waveguide 402.

[0065] exist Figure 4 In the illustrative example shown in FIG, power supply 450 is electrically coupled between electrode 222 and electrode 220 and between electrode 222 and electrode 234. Power supply 450 can be a DC power supply having a negative terminal connected to electrode 220 and electrode 234 and a positive terminal connected to electrode 222. Power supply 450 can be, for example, implemented by a controller (e.g., Figure 8 The computer system described in the embodiment of the present invention is controlled to apply a voltage bias between the corresponding electrodes. That is, the bias voltage can be applied between the electrode 222 and the electrode 234, while the bias voltage is applied between the electrode 222 and the electrode 220. Figure 4 The example shown in FIG provides a single power supply 450, but multiple power supplies may be used in place of power supply 450. For example, a first power supply may be used to apply a first voltage bias across electrode 222 and electrode 220, and a second power supply may be used to apply a second voltage bias across electrode 222 and electrode 234. In this way, the voltage biases may be independently controlled across the respective electrodes simultaneously.

[0066] When based on Figure 4 In the example shown in FIG. 4 (e.g., power supply 450), when a voltage is applied between electrode 222 and electrode 220, negative charges and holes accumulate around interface layer 218. For example, Figure 4 As shown in , negative charges migrate from cathode 204 toward waveguide 402, and holes (positive charges) migrate from anode 206 to waveguide 402. Charge accumulation and changes in carrier concentration cause changes in the waveguide refractive index and propagation losses, as described above.

[0067] When based on Figure 4 In the example shown in FIG, when a voltage is applied between electrodes 234 and 222, positive charge passes through the optical device, thereby generating heat in the waveguide 402. For example, Figure 4 As shown in FIG, holes (e.g., positive charges) migrate from the highly positively doped anode 206 to the intrinsically doped waveguide 402. The flow of charge in the waveguide 402 causes heat to be generated in the resistive region. The heat generation increases the waveguide effective refractive index of the mode as shown below:

[0068]

[0069] The thermal effect is modeled by the steady-state heat equation (Poisson's equation) shown in Equation 3. K is the thermal conductivity, Q is the total charge of the heat source (e.g., carrier concentration), and T is the temperature. The thermal effect can be numerically simulated for a certain structure. Once the gradient of T is obtained, the material's thermo-optic coefficient (dn / dT) can be used to calculate the change in refractive index defined by dn.

[0070] Accordingly, the change in effective refractive index can be enhanced by generating heat from the integrated resistor element in the waveguide 402. For example, a temperature increase can induce an additional and faster change in the effective refractive index in concert with the change in refractive index induced by biasing the voltage applied to the capacitor region.

[0071] In another example, the polarity of the power supply 450 can be reversed. Reversing the polarity of the power supply causes negative charge to migrate from the waveguide 402 toward the electrode 220 and causes holes to migrate from the waveguide 402 toward the electrode 222. Similarly, reversing the polarity of the power supply causes hole charge to migrate from the waveguide 402 toward the electrode 222, thereby reducing the resistive characteristic and lowering the temperature.

[0072] In addition, the optical phase is changed based on the temperature change. As described in the following equation:

[0073]

[0074] Among them, L His the thermal length of waveguide 402, dn / dT is a thermo-optical coefficient (e.g., indicating the change in refractive index in response to temperature) that depends on the material forming waveguide 402, ΔT is the change in temperature of waveguide 402, and λ0 is the free-space wavelength. Thus, biasing electrodes 234 and 222 improves the phase shift of the optical mode in waveguide 202 by enhancing the change induced by MOSCAP 224.

[0075] In addition, regarding the optional light emitting portion, when according to Figure 4 In the example shown in FIG. 2 , when a voltage is applied between electrode 226 and electrode 220 (eg, via power supply 460), negative charges and holes accumulate in optical gain material 232, thereby acting as a pump source. Figure 4 As shown in FIG, the negative terminal of the power supply 460 (which can be a DC power supply) can be connected to the electrode 220, and the positive terminal is connected to the electrode 226. Accordingly, negative charges migrate from the cathode 204 to the optical gain material 232, and holes (positive charges) migrate from the highly doped semiconductor layer 228 through the doped semiconductor layer 230 to the optical gain material 232. The accumulation of charges and holes provides an energy transition state to generate stimulated emission that produces optical gain, and light can be emitted from these stimulated emissions. The emitted light propagates through the cathode 204 into the waveguide 402. A portion of the light in the waveguide 402 can then exit the waveguide 402 via the channel between the groove 212 and the box layer 201 to be connected to the bus waveguide 205. The light can be modulated according to the voltage bias applied to the electrodes, as explained above.

[0076] One non-limiting advantage provided by optical device 400 is that because waveguide 402 is intrinsically doped, optical losses remain low, although heating beneath the laser structure is increased, which may reduce overall wall plug efficiency.

[0077] Figure 5 An example optical device 500 is illustrated according to implementations disclosed herein. Figure 5 Shown with Figure 2 The optical device 200 and / or Figure 3 The optical device 300 is similar to the optical device 500, such that Figure 5 Similar reference numerals in Figure 2 Thus, like the optical devices 200 and 300, the optical device 500 includes the same components as described above. Figure 2 and Figure 3 The capacitor region and optical light emitting portion are illustrated.

[0078] Additionally, the optical device 500 includes a silicon device layer 510 similar to the silicon device layer 210 of the optical device 200, except that the optical waveguide 502, similar to the waveguide 202, is integrated with a PIN junction diode element. For example, the silicon device layer 510 may be intrinsically similar to Figure 2 The optical waveguide 502 is an intrinsically doped semiconductor material (e.g., silicon or other Group IV material) disposed between and in contact with the cathode 540 and anode 206. In this embodiment, the anode 206 comprises a heavily positively doped material. Accordingly, the combination of the cathode 540, the intrinsically doped waveguide 502, and the anode 206 functions as a PIN junction diode and can inject carriers and holes into the waveguide 502. The injection of carriers and holes can also induce a change in temperature (e.g., an increase in heat).

[0079] With the above Figure 4 Similarly, power supply 550 is electrically coupled between electrode 222 and electrode 220 and between electrode 222 and electrode 234. Power supply 550 can be a DC power supply having a negative terminal connected to electrode 220 and electrode 234 and a positive terminal connected to electrode 222. Power supply 550 can be, for example, implemented by a controller (e.g., Figure 8 The computer system described in the embodiment of the present invention is controlled to apply a voltage bias between the corresponding electrodes. That is, the bias voltage can be applied between the electrode 222 and the electrode 234, while the bias voltage is applied between the electrode 222 and the electrode 220. Figure 5 The example shown in FIG provides a single power supply 550, but multiple power supplies may be used in place of power supply 550. For example, a first power supply may be used to apply a first voltage bias across electrode 222 and electrode 220, and a second power supply may be used to apply a second voltage bias across electrode 222 and electrode 234. In this way, the voltage biases may be independently controlled across the respective electrodes simultaneously.

[0080] Similar to the above Figure 4 The optical device 400, when according to Figure 5 In the example shown in FIG, when a voltage is applied between electrode 222 and electrode 220, negative charges and holes accumulate around the interface layer 218. The charge accumulation and the change in carrier concentration result in changes in the waveguide refractive index and propagation loss, as described above.

[0081] When based on Figure 5 In the example shown in FIG, when a voltage is applied between electrode 234 and electrode 222, positive and negative charges accumulate in optical waveguide 502. For example, Figure 5As shown in FIG, negative charge migrates from cathode 540 to optical waveguide 502, and holes (positive charge) migrate from anode 206 to optical waveguide 502. Changes in carrier concentration and distribution in silicon device layer 510 result in additional changes in the refractive index and propagation loss of the waveguide mode. For example, the refractive index change is the result of plasma dispersion effects in waveguide 502. The amount of change can be determined by experimental results, as shown below for a waveguide formed from silicon:

[0082] Δn(@λ0=1310nm)=-2.98×10 -22 ×ΔN 1.016 -1.25×10 -18 ×ΔP 0.835 Equation 5

[0083] Δn(@λ0=1550nm)=-5.4×10 -22 ×ΔN 1.011 -1.53×10 -18 ×ΔP 0.838 Equation 6

[0084] Where Δn is the change in refractive index, ΔN and ΔP are the changes in the density of free electrons (e.g., negative charges) and holes (e.g., positive charges), respectively. Equations 5 and 6 illustrate that hole accumulation results in a larger refractive shift than electron accumulation. Accordingly, one way to improve the phase shift efficiency is by using Figure 5 An example of increasing hole accumulation inside the waveguide 502. Another approach is to improve the phase shift efficiency by increasing the total free carrier density inside the waveguide 502; however, this may result in increased optical losses due to free carrier absorption.

[0085] Furthermore, the accumulation of carriers and holes in the waveguide 502 may induce an increase in temperature (eg, generate heat). Figure 4 As described, thermal generation can enhance the refractive index change and phase shift efficiency.

[0086] In another example, the polarity of the power supply 550 can be reversed. Reversing the polarity of the power supply causes negative charges to migrate from the waveguide 502 toward the electrode 220 and causes holes to migrate from the waveguide 502 toward the electrode 222. Similarly, reversing the polarity of the power supply causes holes to migrate from the waveguide 502 toward the electrode 222 and causes electrons to migrate from the waveguide 502 toward the electrode 234.

[0087] Additionally, Figure 5 The optional light-emitting part is combined as above Figure 3 For example, when Figure 5In the example shown in FIG, when a voltage is applied between electrode 226 and electrode 220 (e.g., via power supply 560), negative charges and holes accumulate in optical gain material 232, thereby acting as a pump source from which light can be emitted and propagated into waveguide 502.

[0088] Figure 6 An example optical device 600 is illustrated according to implementations disclosed herein. Figure 6 Shown with Figure 2 The optical device 200 and / or Figure 3 The optical device 300 is similar to the optical device 600, such that Figure 6 The reference numerals in the figure represent Figure 2 Thus, like the optical devices 200 and 300, the optical device 600 includes the same components as described above. Figure 2 and Figure 3 The capacitor region and optical light emitting portion are illustrated.

[0089] Additionally, the optical device 600 includes a silicon device layer 610 similar to the silicon device layer 210 of the optical device 200, except that the optical waveguide 602, similar to the waveguide 202, is integrated with a PN junction diode element. For example, the silicon device layer 610 may be similar to Figure 5 For example, the cathode 640 is a heavily negatively doped material and the anode 206 is a heavily positively doped material. Figure 6 In the example shown, waveguide 602 includes a first region 605 comprising a positively doped material (e.g., such as silicon or other Group IV materials) and a second region 615 comprising a negatively doped material (e.g., such as silicon or other Group IV materials). Furthermore, a third region 620 is disposed between anode 206 and waveguide 602 comprising a lightly doped material. Accordingly, waveguide 602 is similar to waveguide 202 having an integrated PN junction diode, which can change the carrier concentration in waveguide 602. Changing carrier concentrations can also induce temperature changes (e.g., heat buildup).

[0090] Similar to the previous example, power supply 650 is electrically coupled between electrode 222 and electrode 220 and between electrode 222 and electrode 234. Power supply 650 can be a DC power supply having a negative terminal connected to electrode 220 and electrode 234 and a positive terminal connected to electrode 222. Power supply 650 can be, for example, implemented by a controller (e.g., Figure 8 The computer system described in the embodiment of the present invention is controlled to apply a voltage bias between the corresponding electrodes. That is, the bias voltage can be applied between the electrode 222 and the electrode 234, while the bias voltage is applied between the electrode 222 and the electrode 220. Figure 6The example shown in FIG provides a single power supply 650, but multiple power supplies may be used in place of power supply 650. For example, a first power supply may be used to apply a first voltage bias across electrode 222 and electrode 220, and a second power supply may be used to apply a second voltage bias across electrode 222 and electrode 234. In this way, the voltage biases may be independently controlled across the respective electrodes simultaneously.

[0091] Similar to the previous example, when Figure 6 In the example shown in FIG, when a voltage is applied between electrode 222 and electrode 220, negative charges and holes accumulate around the interface layer 218. The charge accumulation and the change in carrier concentration result in changes in the waveguide refractive index and propagation loss, as described above.

[0092] When based on Figure 6 In the example shown in FIG, when a voltage is applied between electrode 234 and electrode 222, the distribution of positive and negative charges in optical waveguide 602 changes. Figure 6 As shown in FIG, negative charge from the second region 615 migrates to the cathode 340, and holes (positive charge) migrate from the first region 605 to the anode 206. The change in carrier concentration and distribution in the waveguide 602 results in additional changes in the refractive index and propagation loss of the waveguide mode. For example, the refractive index change is the result of plasma dispersion effects in the waveguide 602. The amount of change can be determined from the experimental results of equations 5 and 6, as shown above.

[0093] As shown in Equations 5 and 6, holes provide a larger refractive shift than electrons. Therefore, one way to improve the phase shift efficiency is to use an offset Figure 6 The first approach is to design a PN junction that includes more holes within waveguide 602. A second approach is to increase the total free carrier density within optical waveguide 602 while trading off the optical loss due to free carrier absorption. One approach to addressing optical loss is to utilize different junction shapes. For example, L-shaped and U-shaped PN junctions can improve the overlap between the carrier transition region and the optical mode, thereby improving phase shift efficiency.

[0094] In another example, the polarity of the power supply 650 can be reversed. Reversing the polarity of the power supply causes negative charges to migrate from the waveguide 602 toward the electrode 220 and causes holes to migrate from the waveguide 602 toward the electrode 222. Similarly, reversing the polarity of the power supply causes holes to migrate from the electrode 222 toward the first region 605 and causes electrons to migrate from the electrode 234 toward the second region 615.

[0095] Additionally, Figure 6 The optional light-emitting area is as above combined Figure 3 For example, when Figure 6In the example shown in FIG. 5 , when a voltage is applied between electrode 226 and electrode 220 (e.g., via power supply 660), negative charges and holes accumulate in optical gain material 232, thereby acting as a pump source from which light can be emitted and propagated into waveguide 502.

[0096] Although Figures 4 to 6 An optical device including a light emitting portion is illustrated, but the present disclosure is not so limited. For example, the optical device described above need not include a light emitting portion and can receive light from an external source, for example, similar to the light modulator 100 described above. Additionally, although various materials are described as being negatively doped or positively doped, embodiments herein are not limited thereto, and the polarity doping can be switched. For example, although the above examples describe the cathode 204 as negatively doped and the anode 206, layer 230, and layer 228 as positively doped, the polarity of each layer can be switched such that the cathode 204 is positively doped and the anode 206, layer 230, and layer 228 can be negatively doped. Similarly, when the doping polarity is switched, the polarity of the doping of the second cathode (e.g., cathodes 440, 540, and 640) and the optical waveguide (e.g., optical waveguides 402, 502, and 602) is also switched.

[0097] Figure 7 is a schematic diagram of an example optical device according to embodiments disclosed herein. Figure 7 An optical device 700 including a hybrid MOS capacitor 720 , a semiconductor device 730 , and an optional light emitting portion 710 is illustrated.

[0098] The hybrid MOS capacitor 720 can be configured to induce a change in the effective refractive index and a change in the optical phase, respectively, thereby causing optical intensity modulation and attenuation, for example, based on applying a bias voltage to the hybrid MOS capacitor 720. For example, the hybrid MOS capacitor 720 can be implemented as the anode 206, the cathode 204, and the interface layer 218 in contact with the waveguide 202, as described above in conjunction with Figures 2 to 6 described.

[0099] The semiconductor device 730 can be configured to induce an additional effective refractive index change and / or optical phase change, for example, based on biasing a voltage applied to the semiconductor device 730, thereby enhancing the modulation and attenuation induced by the capacitor 720. In one example, the semiconductor device 730 can be implemented as a resistor element, for example, as embodied by the waveguide 402 connected to the anode 206 and the silicon device layer 410, as described above in conjunction with Figure 4 In another example, the semiconductor device 730 can be implemented as a PIN junction diode element, for example, embodied by the waveguide 502 connected between the anode 206 and the silicon device layer 510, as described above in conjunction with Figure 5In another example, the semiconductor device 730 can be implemented as a PN junction diode element, for example, embodied by the waveguide 602 between the anode 206 and the cathode 640, as described above in conjunction with Figure 6 described.

[0100] The light emitting portion 710 can be configured to emit light, for example, laser light, by inducing an electrical state in the optical gain material based on applying a bias voltage to the light emitting portion 710. For example, the light emitting portion 710 can be implemented as a highly doped semiconductor layer 228, a doped semiconductor layer 230, an optical gain material 232, and a cathode 204, as described above in conjunction with Figures 2 to 6 described.

[0101] In addition to enhancing the modulation and phase shifting of the MOSCAP ring resonator, the examples herein can also achieve more complex functionality with a wider range and tuning capabilities. For example, by using phase shifting and modulation through separate electrical contacts (e.g., applying a voltage bias between electrode 220 and electrode 222 while simultaneously applying a bias between electrode 234 and electrode 222), the embodiments herein can achieve not only non-return-to-zero (NRZ) modulation with a large optical modulation amplitude (OMA) using two synchronized NRZ electrical signals, but also pulse amplitude modulation (e.g., PAM4) using two separate NRZ electrical signals. For example, independently biasing the voltage applied to each pair of electrode contacts allows for separate modulation. As an illustrative example, the MOSCAP 720 and the semiconductor device 730 can be independently biased to induce modulation of the phase shift property. Furthermore, the biasing of the light-emitting portion 710 can permit modulation of the amplitude of the output light along with modulation of the phase shift. As an illustrative example, by applying a bias voltage across the electrodes 226 and 220 of the light emitting portion 710 to induce amplitude modulation of the light (e.g., causing the light intensity to vary), and also applying a bias voltage to the MOSCAP 720 and the semiconductor device 730 to induce phase shift modulation. Accordingly, PAM4 modulation can be achieved by combining Figures 2 to 6 An example implementation of the description.

[0102] Figure 8 A block diagram of an example computer system 800 is depicted in which various embodiments described herein may be implemented. The computer system 800 includes a bus 802 or other communication mechanism for transmitting information, and one or more hardware processors 804 coupled to the bus 802 for processing information. The hardware processor(s) 804 may be, for example, one or more general-purpose microprocessors. As described above, the computer system 800 may be implemented to control the power supplies described above (e.g., one or more power supplies 450, 460, 550, 560, 650, and 660).

[0103] Computer system 800 also includes a main memory 806, such as random access memory (RAM), cache, and / or other dynamic storage devices, coupled to bus 802 for storing information and instructions to be executed by processor 804. Main memory 806 may also be used to store temporary variables or other intermediate information during execution of instructions to be executed by processor 804. Such instructions, when stored in a storage medium accessible to processor 804, render computer system 800 a special-purpose machine customized to perform the operations specified in the instructions.

[0104] Computer system 800 further includes a read only memory (ROM) 808 or other static storage device coupled to bus 802 for storing static information and instructions for processor 804. A storage device 810, such as a magnetic disk, optical disk, or USB thumb drive (flash memory drive), is provided and coupled to bus 802 for storing information and instructions.

[0105] The computer system 800 may be coupled to a display 812, such as a liquid crystal display (LCD) (or touch screen), via bus 802 for displaying information to a computer user. An input device 814, including alphanumeric and other keys, is coupled to bus 802 for communicating information and command selections to processor 804. Another type of user input device is a cursor control 816, such as a mouse, trackball, or cursor direction keys, for communicating direction information and command selections to processor 804 and for controlling cursor movement on display 812. In some embodiments, the same direction information and command selections as with a cursor control can be implemented by receiving touches on a touch screen without a cursor.

[0106] The computing system 800 may include a user interface module for implementing a GUI, which may be stored in a mass storage device as executable software code executed by the computing device(s). By way of example, this module and other modules may include components (such as software components, object-oriented software components, class components, and task components), processes, functions, properties, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables.

[0107] Generally, the terms "component," "engine," "system," "database," "data storage," and the like as used herein may refer to logic implemented in hardware or firmware, or to a set of software instructions written in a programming language such as Java, C, or C++, which may have entry and exit points. Software components may be compiled and linked to executable programs, installed in dynamic link libraries, or written in interpreted programming languages ​​such as BASIC, Perl, or Python. It should be understood that software components may be called from other components or from themselves, and / or may be called in response to detected events or interrupts. Software components configured for execution on a computing device may be provided in a computer-readable medium such as a compact disk, digital video disk, flash memory drive, magnetic disk, or any other tangible medium, or may be provided as a digital download (and may be stored originally in a compressed format or installable format that requires installation, decompression, or decryption before execution). Such software code may be stored in part or in whole on a memory device of the executing computing device for execution by the computing device. Software instructions may be embedded in firmware such as an EPROM. It will be further understood that hardware components may include connected logic units such as gates and flip-flops, and / or may include programmable units such as programmable gate arrays or processors.

[0108] The computer system 800 can implement the techniques described herein using custom hard-wired logic, one or more ASICs or FPGAs, firmware, and / or program logic that, in combination with the computer system, makes the computer system 800 a special-purpose machine or programs it to be a special-purpose machine. According to one embodiment, the techniques herein are performed by the computer system 800 in response to the processor(s) 804 executing one or more sequences of one or more instructions contained in the main memory 806. Such instructions can be read into the main memory 806 from another storage medium, such as the storage device 810. Execution of the sequences of instructions contained in the main memory 806 causes the processor(s) 804 to perform the process steps described herein. In alternative embodiments, hard-wired circuitry can be used in place of or in combination with software instructions.

[0109] As used herein, the term "non-transitory media" and similar terms refer to any medium that stores data and / or instructions that cause a machine to operate in a particular manner. Such non-transitory media may include non-volatile media and / or volatile media. Non-volatile media include, for example, optical or magnetic disks, such as storage device 810. Volatile media include dynamic memory, such as main memory 806. Common forms of non-transitory media include, for example, floppy disks, diskettes, hard disks, solid-state drives, magnetic tape or any other magnetic data storage medium, CD-ROMs, any other optical data storage medium, any physical medium with a pattern of holes, RAM, PROM and EPROM, flash EPROM, NVRAM, any other memory chip or cartridge, and networked versions of these media.

[0110] Non-transient media are distinct from, but can be used in conjunction with, transmission media. Transmission media facilitate the transfer of information between non-transient media. Examples of transmission media include coaxial cables, copper wire, and optical fiber, including the wires comprising bus 802. Transmission media can also take the form of acoustic or light waves, such as those generated during radio wave and infrared data communications.

[0111] The computer system 800 also includes a communication interface 818 coupled to the bus 802. The communication interface 818 provides two-way data communication coupled to one or more network links that are connected to one or more local networks. For example, the communication interface 818 can be an integrated services digital network (ISDN) card, a cable modem, a satellite modem, or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, the network interface 818 can be a local area network (LAN) card for providing a data communication connection to a compatible LAN (or a WAN component for communicating with a WAN). Wireless links can also be implemented. In any such implementation, the communication interface 818 sends and receives electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information. The communication interface 818 can be communicatively coupled to one or more power sources (e.g., Figures 4 to 6 One or more power supplies 450, 460, 550, 560, 650, and 660).

[0112] A network link typically provides data communication to other data devices through one or more networks. For example, a network link can provide a connection through a local network to a host computer or to data equipment operated by an Internet Service Provider (ISP). The ISP, in turn, provides data communication services through the global packet data communication network now commonly referred to as the "Internet." Both the local network and the Internet use electrical, electromagnetic, or optical signals that carry digital data streams. The signals through the various networks and the signals on the network link and through the communication interface 818 (which carry digital data to and from the computer system 800) are example forms of transmission media.

[0113] Computer system 800 can send messages and receive data, including program code, through the network(s), network links, and communication interface 818. In the Internet example, a server can transmit the requested code for an application program through the Internet, an ISP, a local network, and communication interface 818.

[0114] The received code can be executed by the processor 804 as it is received and / or stored in the storage device 810, or other non-volatile memory, for later execution. Accordingly, the computer system 800 can be configured to control the voltage bias applied between the contact electrodes by sending instructions to one or more power supplies over the communication interface(s) 818 according to instructions stored in the main memory 806 and / or ROM 808.

[0115] Each process, method, and algorithm described in the preceding sections can be implemented in code components executed by one or more computer systems or computer processors including computer hardware and automated in whole or in part by these code components. The one or more computer systems or computer processors can also operate to support the performance of related operations in a "cloud computing" environment, or operate as "software as a service" (SaaS). These processes and algorithms can be implemented in part or in whole in dedicated circuits. The various features and processes described above can be used independently of each other, or can be combined in various ways. Different combinations and sub-combinations are intended to fall within the scope of this disclosure, and certain method blocks or process blocks can be omitted in some embodiments. The methods and processes described herein are also not limited to any particular order, and the blocks or states associated with these methods and processes can be performed in other appropriate orders, or can be performed in parallel, or in some other manner. Blocks or states can be added to or removed from the disclosed example embodiments. The performance of certain operations or processes can be distributed to multiple computer systems or computer processors so that they do not reside only in a single machine, but are deployed across multiple machines.

[0116] As used herein, circuit can utilize any form of hardware, software or its combination to implement.For example, one or more processors, controllers, ASIC, PLA, PAL, CPLD, FPGA, logic unit, software routine or other mechanisms can be implemented to form circuit.In an embodiment, various circuits described herein can be implemented as discrete circuits, or described functions and features can be shared partially or entirely among one or more circuits.Even if various features or functional elements can be described or advocated as separate circuits respectively, these features and functions also can be shared between one or more common circuits, and this description should not require or imply that separate circuits are needed to implement such features or functions.When using software to implement circuit in whole or in part, such software can be implemented to operate together with a computing system or a processing system (such as computer system 800) that can perform the function described about the software.

[0117] As used herein, the term "or" may be interpreted in an inclusive or exclusive sense. Furthermore, descriptions of resources, operations, or structures in the singular should not be construed to exclude the plural. Unless expressly stated otherwise, or understood otherwise within the context in which they are used, conditional language (such as, among others, "can," "could," "might," or "may") is generally intended to convey that certain embodiments include and other embodiments do not include certain features, elements, and / or steps.

[0118] Unless expressly stated otherwise, the terms and phrases used in this document and their variations should be interpreted as open-ended rather than restrictive. Adjectives such as "conventional," "traditional," "normal," "standard," "known," and terms of similar meaning should not be interpreted as limiting the items described to items available for a given time period or at a given time, but should be understood to encompass conventional, customary, normal, or standard technology that may be available or known at any time, now or in the future. In some cases, the presence of broad words and phrases such as "one or more," "at least," "but not limited to," or other similar phrases should not be understood to mean that a narrower situation is intended or required where such broad phrases may not be present.

Claims

1. An optical device comprising: substrate; A heterogeneous metal oxide semiconductor (MOS) capacitor is formed on the substrate and includes: optical waveguides; a first cathode comprising a first material and formed in the optical waveguide; an anode formed in the optical waveguide, the anode comprising a second material different from the first material; and a dielectric disposed between the first cathode and the anode, the dielectric comprising an oxide of the first material and an oxide of the second material, wherein the hetero-MOS capacitor is defined between the anode and the first cathode; and A semiconductor device layer is provided between the substrate and the hetero MOS capacitor and is formed in the optical waveguide. 2 . The optical device according to claim 1 , further comprising a light emitting diode disposed on the hetero-MOS capacitor opposite to the substrate.

3. The optical device according to claim 2, wherein: The light emitting diode includes an optical gain material formed on the first cathode opposite the dielectric.

4. The optical device according to claim 1, wherein The optical device includes a micro-ring shape.

5. The optical device according to claim 1, wherein The semiconductor device layer and the anode define a resistor element formed in the optical waveguide.

6. The optical device according to claim 5, wherein: The semiconductor device layer includes a second cathode including a third material and formed in the optical waveguide, wherein the anode and the second cathode each include a dopant of the same polarity, and wherein the optical waveguide is intrinsically doped.

7. The optical device according to claim 1, wherein: The optical waveguide includes a first region and a second region, the first region and the second region defining a pn junction diode formed in the optical waveguide.

8. The optical device according to claim 7, wherein: The semiconductor device layer includes a second cathode including a third material and formed in the optical waveguide, wherein the anode and the second cathode each include dopants of opposite polarity, and wherein the first region includes dopants of the same polarity as the anode and the second region includes dopants of the same polarity as the second cathode.

9. The optical device according to claim 1, wherein: The semiconductor device layer includes a third material having an electrical polarity opposite to that of the anode, wherein the semiconductor device layer, the optical waveguide, and the anode define a PIN junction diode.

10. The optical device according to claim 9, wherein: The semiconductor device layer includes a second cathode including a third material and formed in the optical waveguide, wherein the anode and the second cathode each include dopants of opposite polarity, and wherein the optical waveguide is intrinsically doped.

11. The optical device according to claim 1, wherein: The first material includes a III-V material.

12. The optical device according to claim 1, wherein The second material includes a Group IV material.

13. The optical device according to claim 1, wherein: The semiconductor device layer includes a Group IV material.

14. A microring laser comprising: A hybrid metal oxide semiconductor (MOS) capacitor is formed on a substrate and includes: optical waveguides; a first cathode comprising a Group III-V material and formed in the optical waveguide; an anode formed in the optical waveguide, the anode comprising a Group IV material; and a dielectric disposed between the first cathode and the anode, the dielectric comprising an oxide of the III-V material and an oxide of a Group V material, wherein the hybrid MOS capacitor is defined between the anode and the first cathode; a second cathode comprising a Group IV material, disposed between the substrate and the first cathode and located on a side of the optical waveguide opposite to the anode, the second cathode being formed in the optical waveguide and configured to integrate one of a resistor element, a pn junction diode element, and a PIN junction diode element into the optical waveguide; and A light emitting portion includes an optical gain material and is disposed on the first cathode opposite to the substrate.

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