Photonic coupler, forming method thereof and photonic device

Abstract

The photonic coupler can comprise a first input waveguide, a second input waveguide, a first output waveguide, a second output waveguide and a coupling region, wherein the first input waveguide, the second input waveguide, the first output waveguide, and the electromagnetic field associated with two or more of the second output waveguide in the coupling region overlap each other, and the electro-optical device is located in the coupling region and includes a refractive index, and the refractive index is a first function of the applied voltage. The coupling region may include an effective coupling length along the optical propagation direction, and the effective coupling length is a second function of a product of a physical length of the coupling region and a refractive index of the electro-optical device. Due to the evanescent coupling, the voltage applied to the photonic coupler can be adjusted to control the mixing ratio of electromagnetic energy transmitted between the input waveguide and the output waveguide. The invention further relates to a forming method of the photonic coupler and a photonic device.

Description

Technical Field

[0001] Embodiments of the present invention relate to photonic integrated circuits, and more particularly to their coupling regions. Background Art

[0002] Many computing applications employ optical (i.e., photonic) signals to provide fixed high-speed data transmission. Currently, a variety of emerging technologies are being developed to provide the ability to perform computational operations directly on optical / photonic signals. Silicon photonics is a promising technical field that uses semiconductor device fabrication technologies to provide systems containing integrated electronic and photonic components. These components can be used to generate, route, modulate, process, and detect light. These functions can together form an optical analog-to-electronic integrated circuit and can thus constitute a photonic integrated circuit. Summary of the Invention

[0003] A photonic coupler provided by an embodiment of the present invention includes: a first input waveguide and a second input waveguide; a first output waveguide and a second output waveguide; a coupling region, wherein an electromagnetic field overlap is present between two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide in the coupling region; and an electro-optic device located in the coupling region and including a refractive index, and the refractive index is a first function of an applied voltage.

[0004] A photonic device provided by an embodiment of the present invention includes: a first input waveguide, a second input waveguide, a third input waveguide, and a fourth input waveguide; a first output waveguide, a second output waveguide, a third output waveguide, and a fourth output waveguide; a first photonic coupler that mixes a first input photonic signal received from the first input waveguide and a second input photonic signal received from the second input waveguide to generate a first output photonic signal and a second output photonic signal and respectively provide them to the first output waveguide and the second output waveguide; a second photonic coupler that mixes a third input photonic signal received from the third input waveguide and a fourth input photonic signal received from the fourth input waveguide to generate a third output photonic signal and a fourth output photonic signal and respectively provide them to the third output waveguide and the fourth output waveguide; and a first regulator section that changes the amplitude or phase of the first output photonic signal to generate a third input photonic signal and provide it to the third input waveguide, wherein at least one of the first photonic coupler and the second photonic coupler includes an electro-optic device that determines the mixing ratio of the first input photonic signal and the second input photonic signal, or the mixing ratio of the third input photonic signal and the fourth input photonic signal, based on a voltage applied to the first photonic coupler or the second photonic coupler, respectively.

[0005] A method of forming a photon coupler provided by an embodiment of the present invention includes: forming a first input waveguide and a second input waveguide; forming a first output waveguide and a second output waveguide; and forming a coupling region including an electro-optic device, and the refractive index of the electro-optic device is a function of the applied voltage, wherein the electromagnetic fields associated with two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide in the coupling region overlap each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a diagram of various components available for a photonic computing system.

[0007] Figure 2A is a top view of an electro-optic adjuster available for a photonic computing system.

[0008] Figure 2B is a top view of an optical switch available for a photonic computing system.

[0009] Figure 2C is a dielectric waveguide along Figure 2A and Figure 2B a vertical cross-sectional view of the vertical plane C-C' in.

[0010] Figure 3A is a top view of a photonic device including a photon coupler and a photon adjuster part in various embodiments.

[0011] Figure 3B is in various embodiments, Figure 3A a vertical cross-sectional view of the first adjuster part of the photonic device.

[0012] Figure 3C is in various embodiments, Figure 3A a vertical cross-sectional view of the first photon coupler of the photonic device.

[0013] Figure 4 is a top view of another photonic device including a photon coupler and a photon adjuster part in various embodiments.

[0014] Figure 5A is in various embodiments, Figure 3A and Figure 4 a vertical cross-sectional view of the other adjuster part of the photonic devices (300, 400).

[0015] Figure 5B is in various embodiments, available for Figure 3A and Figure 4 a vertical cross-sectional view of the other photon couplers of the photonic devices (300, 400).

[0016] Figure 6A is in various embodiments, Figure 3AVertical cross-sectional view of other adjuster parts of the photon device.

[0017] Figure 6B In various embodiments, it can be used for Figure 3A and Figure 4 Vertical cross-sectional view of other photon couplers of the photon devices (300, 400).

[0018] Figure 7A In various embodiments, it is a vertical cross-sectional view of an intermediate structure that can be used to form a photon coupler.

[0019] Figure 7B In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0020] Figure 7C In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0021] Figure 7D In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0022] Figure 7E In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0023] Figure 7F In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0024] Figure 7G In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0025] Figure 7H In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0026] Figure 7I In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0027] Figure 7J In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0028] Figure 7K In various embodiments, it is a vertical cross-sectional view of other intermediate structures that can be used to form a photon coupler.

[0029] Figure 7L In various embodiments, it is a vertical cross-sectional view of a photon coupler.

[0030] Figure 8It is a flowchart of the steps of a method for forming a photon coupler in multiple embodiments.

[0031] Among them, the reference numerals are explained as follows:

[0032] B - B', C - C': Vertical planes

[0033] 102: Photon source

[0034] 104: Dielectric waveguide

[0035] 104a: Input waveguide

[0036] 104a1: First input waveguide

[0037] 104a2: Second input waveguide

[0038] 104a3: Third input waveguide

[0039] 104a4: Fourth input waveguide

[0040] 104b: Output waveguide

[0041] 104b1: First output waveguide

[0042] 104b2: Second output waveguide

[0043] 104b3: Third output waveguide

[0044] 104b4: Fourth output waveguide

[0045] 106: Optical detector

[0046] 108: Optical adjuster

[0047] 108a: First adjuster part

[0048] 108b: Second adjuster part

[0049] 108c: Third adjuster part

[0050] 108d: Fourth adjuster part

[0051] 110: Photon processing component

[0052] 200a: Electro - optic adjuster

[0053] 200b: Optical switch

[0054] 204a: First waveguide component

[0055] 204b: Second waveguide component

[0056] 204c: Third waveguide component

[0057] 204d: Fourth waveguide component

[0058] 208: Photonic coupler

[0059] 208a: First photonic coupler

[0060] 208b: Second photonic coupler

[0061] 209: Coupling region

[0062] 210: Core part

[0063] 212: Cover part

[0064] 214: Electromagnetic field distribution

[0065] 300, 400: Photonic device

[0066] 302a: First end

[0067] 302aL: Semiconductor layer

[0068] 302b: Second end

[0069] 302b1: First component

[0070] 302b2: Second component

[0071] 302bL: Laminate

[0072] 304: Dielectric layer

[0073] 306a, 306a1: First electrical contact

[0074] 306a2, 306b, 306b1: Second electrical contact

[0075] 306b2: Third electrical contact

[0076] 308: Coupled waveguide component

[0077] 308a: First coupled waveguide component

[0078] 308b: Second coupled waveguide component

[0079] 502: Ridge waveguide structure

[0080] 502a: First ridge waveguide structure

[0081] 502b: Second ridge waveguide structure

[0082] 700a, 700b, 700c, 700d, 700e, 700f, 700g, 700h, 700i, 700j, 700k: Intermediate structure

[0083] 702: Contact via opening

[0084] 704a: n-type well

[0085] 704b: p-type well

[0086] 800: Method

[0087] 802, 804, 806, 808: Steps Detailed implementation mode

[0088] The following detailed description can be combined with the schematic diagrams for better understanding of various aspects of the present invention. It should be noted that various structures are only for illustrative purposes and are not drawn to scale, as is normal in the industry. In fact, for clear illustration, the sizes of various structures can be arbitrarily increased or decreased.

[0089] The different embodiments or examples provided below can implement different structures of the present invention. The embodiments of the following specific components and arrangements are used to simplify the content of the present invention rather than limit the present invention. For example, the description of forming a first component on a second component includes embodiments where the two are in direct contact, or embodiments where there are other additional components between the two rather than in direct contact. In addition, the same reference numerals can be reused in multiple examples of the present invention for simplicity, but the components with the same reference numerals in multiple embodiments and / or settings do not necessarily have the same corresponding relationship.

[0090] In addition, spatial relative terms such as "below", "beneath", "lower", "above", "higher", or similar terms can be used to simplify the relative relationship between one element and another in the schematic diagram. The spatial relative terms can be extended to elements used in other directions, not limited to the directions in the schematic diagram. The elements can also be rotated by 90 degrees or other angles, so the directional terms are only used to illustrate the directions in the schematic diagram. Units with the same reference numerals can refer to the same units, such as having the same material composition and the same thickness range.

[0091] An electro-optic element that adjusts the effective coupling length based on the voltage applied to the electro-optic device is beneficial to the photon coupler of the embodiment. In this regard, the effective coupling length can determine the mixing ratio of the first electromagnetic energy transmitted from the first input waveguide to the second output waveguide relative to the second electromagnetic energy transmitted from the second input waveguide to the first output waveguide. For example, by designing the effective coupling length to be an integer multiple of the wavelength plus a quarter of the wavelength, the photon coupler of the embodiment can be designed to operate as a 50 / 50 beam splitter without applying voltage. However, due to manufacturing tolerances, the photon coupler may have defects, resulting in errors in the mixing ratio of the transmitted electromagnetic energy.

[0092] Thus, although the photon coupler is designed as a 50 / 50 beam splitter, due to defects, the photon coupler actually acts as a 49 / 51 beam splitter (or a 41 / 59 beam splitter). The electro-optic devices of various embodiments can be appropriately biased to correct the mixing ratio. In this consideration, the bias voltage can be used to correct the 49 / 51 performance (or other percentage errors) by adjusting the voltage-dependent effective coupling length to achieve the desired 50 / 50 beam splitter performance. In other embodiments, the electro-optic devices can be used to achieve various other mixing ratios in other applications. In this way, the photon coupler of the embodiment can adjust the applied voltage to easily correct the errors in the device performance.

[0093] A photon coupler of an embodiment can include a first input waveguide, a second input waveguide, a first output waveguide, a second output waveguide, and a coupling region, wherein the electromagnetic fields associated with two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide overlap with each other, and an electro-optic device is located in the coupling region and includes a refractive index, and the refractive index is a first function of the applied voltage. The coupling region can include an effective coupling length along the optical propagation direction, and the effective coupling length is a second function of the product of the physical length of the coupling region and the refractive index of the electro-optic device. Due to evanescent coupling, the voltage applied to the photon coupler can be adjusted to control the mixing ratio of the electromagnetic energy transmitted between the input waveguide and the output waveguide.

[0094] A photon device of an embodiment can include a first input waveguide, a second input waveguide, a third input waveguide, a fourth input waveguide, a first output waveguide, a second output waveguide, a third output waveguide, a fourth output waveguide, a first photon coupler, and a second photon coupler. The first photon coupler can mix a first input photon signal received from the first input waveguide and a second input photon signal received from the second input waveguide to generate a first output photon signal and a second output photon signal, which are respectively provided to the first output waveguide and the second output waveguide.

[0095] The second photon coupler can mix a third input photon signal received from the third input waveguide and a fourth input photon signal received from the fourth input waveguide to generate a third output photon signal and a fourth output photon signal, which are respectively provided to the third output waveguide and the fourth output waveguide. At least one of the first photon coupler and the second photon coupler can include an electro-optic device that determines the mixing ratio of the first input photon signal and the second input photon signal, or the mixing ratio of the third input photon signal and the fourth input photon signal, based on the voltage applied to the first photon coupler or the second photon coupler, respectively.

[0096] A method of forming a photon coupler according to an embodiment may include forming a first input waveguide and a second input waveguide; forming a first output waveguide and a second output waveguide; and forming a coupling region that includes an electro-optic device, and the refractive index of the electro-optic device is a function of an applied voltage. In this way, the electromagnetic fields associated with two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide in the coupling region overlap with each other. The method may further include forming a first coupling waveguide component that is optically coupled to the first input waveguide and the first output waveguide; and forming a second coupling waveguide component that is optically coupled to the second input waveguide and the second output waveguide, such that each of the first coupling waveguide component and the second coupling waveguide component includes an electro-optic device. The step of forming the coupling region in the method further includes: forming a first end that includes n-type polysilicon; forming a second end that includes p-type silicon; and forming a dielectric layer to separate the first end and the second end, such that a voltage difference applied between the first end and the second end changes the effective refractive index of the photon coupler.

[0097] Figure 1 FIGS. - Figure 1 are diagrams of various components that can be used in a photonic computing system. The system components may include a generating device such as a photon source 102 (such as a laser or a light-emitting diode), a routing device (which may include a plurality of dielectric waveguides 104 arranged to route optical / photon signals), and a detector (which may include one or more optical detectors 106 arranged to detect optical / photon signals and convert the received optical / photon signals into output electrical signals). Additional components may include an adjustment device, which may include one or more optical adjusters 108 and a photon processing component 110.

[0098] One or more optical adjusters 108 may be arranged to apply amplitude and / or phase adjustments to the input photon signals generated by the photon source 102. The photon processing component 110 may be arranged to perform logical operations on the adjusted optical signals. One or more optical adjusters 108 may receive input electrical signals and may adjust the amplitude and / or phase of the input optical signals in response to the input electrical signals. One or more optical adjusters 108 in this manner may be used to convert data provided in the form of electrical signals into optically encoded data. Similarly, one or more optical detectors 106 may convert the processed optical signals back into output electrical signals.

[0099] Figure 2A FIG. is a top view of an electro-optic adjuster 200a that can be used in a photonic computing system. The vertical plane C-C' refers to defining Figure 2CThe vertical plane of the vertical cross-section shown. The electro-optic modulator 200a may include an input waveguide 104a and an output waveguide 104b. The input waveguide 104a may be arranged to receive an input optical signal, while the output waveguide 104b may be arranged to provide an output optical signal, and the output optical signal is an adjusted version of the input optical signal. As shown, the output waveguide 104a may bifurcate into a first waveguide component 204a and a second waveguide component 204b. In this way, the input waveguide 104a, the first waveguide component 204a, and the second waveguide component 204b may act as a beam splitter.

[0100] The input signal received by the input waveguide 104a may be split into two optical signals (i.e., two copies of the input optical signal), which may be carried by the first waveguide component 204a and the second waveguide component 204b, respectively. The first optical signal carried by the first waveguide component 204a may be provided to the first modulator section 108a, while the second optical signal carried by the second waveguide component 204b may be provided to the second modulator section 108b. The first modulator section 108a and the second modulator section 108b may adjust the amplitude and / or phase of the individual first optical signal and second optical signal.

[0101] The adjusted first optical signal may be transmitted along the third waveguide component 204c, while the adjusted second optical signal may be transmitted along the fourth waveguide component 204d. The adjusted first optical signal and the adjusted second optical signal may then be combined to form an output signal and provided to the output waveguide 104b. In this regard, the third waveguide component 204c may be optically coupled to the first modulator section 108a, and the fourth waveguide component 204d may be optically coupled to the second modulator section 108b. The third waveguide component 204c and the fourth waveguide component 204d may in turn be optically coupled to the output waveguide 104b. In this way, the third waveguide component 204c, the fourth waveguide component 204d, and the output waveguide 104b may act as a combiner.

[0102] The first modulator section 108a and the second modulator section 108b may each adjust the individual first optical signal and second optical signal according to the electro-optic effect. In this regard, the first modulator section 108a and the second modulator section 108b may each include a material with electro-optical properties. This electro-optical material has optical properties (such as refractive index and absorption coefficient), which can be changed as a function of the applied bias voltage (i.e., potential difference).

[0103] Figure 2B is a top view of the optical switch 200b that can be used in a photonic computing system. The vertical plane C-C' refers to the vertical plane that defines Figure 2CThe vertical cross-sectional view shown. In one embodiment, the optical switch 200b can be implemented as a Mach-Zehnder interferometer, which can be integrated with a first photon coupler 208a (such as a first 50 / 50 beam splitter) and a second photon coupler 208b (such as a second 50 / 50 beam splitter). The first photon coupler 208a and the second photon coupler 208b can each be regarded as a directional coupler or a photon coupler.

[0104] The optical switch 200b can include a first input waveguide 104a1 and a second input waveguide 104a2, which can each provide individual input signals to the first photon coupler 208a. The first photon coupler 208a can provide individual output signals to a first output waveguide 104b1 and a second output waveguide 104b2. The first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2 can each be arranged to support a single-mode or multi-mode light beam carrying an optical signal.

[0105] The first photon coupler 208a can receive a first optical signal from the first input waveguide 104a1 and a second input signal from the second input waveguide 104a2. By the phenomenon of evanescent coupling, 50% of the first optical signal in the coupling region 209 can be introduced into the first output waveguide 104b1, and the other 50% of the first optical signal can be introduced into the second output waveguide 104b2. At the same time, 50% of the second optical signal can be introduced into the first output waveguide 104b1, and the other 50% of the second optical signal can be introduced into the second output waveguide 104b2. In this way, the first optical signal and the second optical signal between the first output waveguide 104b1 and the second output waveguide 104b2 can be evenly split.

[0106] As Figure 2B shown, the first photon coupler 208a can include a first coupled waveguide component 308a, which is optically coupled to the first input waveguide 104a1 and the first output waveguide 104b1; and a second coupled waveguide component 308b, which is optically coupled to the second input waveguide 104a2 and the second output waveguide 104b2. Evanescent coupling occurs when the first coupled waveguide component 308a and the second coupled waveguide component 308b are sufficiently close to each other, thereby causing the electric fields associated with the individual first coupled waveguide component 308a and the second coupled waveguide component 308b to overlap. The second photon coupler 208b can also include a similar structure, such as the first coupled waveguide component 308a and the second coupled waveguide component 308b.

[0107] The first adjuster section 108a and the second adjuster section 108b can respectively receive signals from the first output waveguide 104b1 and the second output waveguide 104b2, and can adjust the amplitude and / or phase of the received signals. In this regard, the first adjuster section 108a and the second adjuster section 108b can each include an electro-optic material having electro-optic properties (such as refractive index and absorption coefficient), and the electro-optic properties can be changed as a function of, for example, the applied bias voltage. In this way, a predetermined bias voltage potential can be applied in a particular embodiment to controllably change the phase of the optical signals propagating through the first adjuster section 108a and the second adjuster section 108b.

[0108] After propagating through the first photon coupler 208a, the signals propagating in the first output waveguide 104b1 and the second output waveguide 104b2 can have a well-defined phase relationship with respect to each other (i.e., in-phase, 180 degrees out-of-phase, or a similar phase). In this way, the first adjuster section 108a and the second adjuster section 108b can introduce a predetermined phase difference between the signals received from the first output waveguide 104b1 and the second output waveguide 104b2. Then, the signal passing through the first adjuster section 108a can be provided to the third input waveguide 104a3, and the signal passing through the second adjuster section 108b can be provided to the fourth input waveguide 104a4. Then, the individual signals received from the third input waveguide 104a3 and the fourth input waveguide 104a4 can be provided to the second photon coupler 208b.

[0109] After the second photon coupler 208b, it can transmit 50% of the signal received from the third input waveguide 104a3 to the third output waveguide 104b3, and can transmit the other 50% of the signal received from the third input waveguide 104a3 to the fourth output waveguide 104b4. At the same time, it can transmit 50% of the signal received from the fourth input waveguide 104a4 to the third output waveguide 104b3, and can transmit the other 50% of the signal received from the fourth input waveguide 104a4 to the fourth output waveguide 104b4. The third input waveguide 104a3, the fourth input waveguide 104a4, the third output waveguide 104b3, and the fourth output waveguide 104b4 can each be arranged to carry a single-mode or multi-mode light beam of an optical signal.

[0110] The relative phase between the signals propagating in the third input waveguide 104a3 and the fourth input waveguide 104a4 can determine which signals appear in the third output waveguide 104b3 and the fourth output waveguide 104b4. Due to the phenomenon of constructive and destructive interference that can switch the signals, the signal only appears in the third output waveguide 104b3 (e.g., the light beams can be in-phase) or the fourth output waveguide 104b4 (e.g., the light beams can be out-of-phase). In this way, by applying a specific predetermined bias voltage to the first adjuster section 108a and the second adjuster section 108b, the optical switch 200b can provide a switching function, where the optical signal can be directed to the third output waveguide 104b3 or the fourth output waveguide 104b4, as a function of the bias voltage applied to the first adjuster section 108a and the second adjuster section 108b. Although the two arms of the optical switch 200b (this embodiment is a Mach-Zehnder interferometer) in the figure contain phase adjustment sections (i.e., the first adjuster section 108a and the second adjuster section 108b), other embodiments include optical switches 200b with phase adjustment devices only in a single arm, as described in conjunction with Figure 3A the content detailed below.

[0111] Although Figure 2B implementing a Mach-Zehnder interferometer as the optical switch 200b, the embodiments are not limited to this specific switch structure. The scope of the embodiments of the present invention can include a variety of other phase adjustment devices, including ring resonator designs, Mach-Zehnder adjusters, general Mach-Zehnder adjusters, or the like. In some embodiments, the photon adjuster (108a, 108b) devices described herein can be used in quantum computing systems. These photon adjuster (108a, 108b) devices can be adapted for use in other types of optical systems. For example, other computing, communication, and / or technology systems in various embodiments can employ the photon adjuster (108a, 108b) devices to direct optical signals (such as single photons or continuous-wave optical signals) into the system or network, and the photon devices described herein can be used in these systems.

[0112] Figure 2C is a vertical cross-sectional view of the dielectric waveguide 104 (such as silicon / silica). As described above, the vertical plane used in the illustrated figure is labeled as Figure 2C and the vertical plane C-C' in Figure 2A and Figure 2B The dielectric waveguide 104 can include a core portion 210 and a cladding portion 212. The core portion 210 and the cladding portion 212 can each be configured to transmit light of a specific wavelength (such as infrared). The core portion 210 and the cladding portion 212 can be formed using the manufacturing processes of semiconductor devices, as detailed below.

[0113] The refractive index of the core portion 210 can be set to be higher than that of the cladding portion 212. For example, the composition of the core portion 210 can be doped or undoped silicon (with a refractive index of 3.88), while the composition of the cladding portion 212 can be silicon oxide (with a refractive index of 1.46). Due to the total internal reflection phenomenon caused by the refractive index of the core portion 210 being greater than that of the cladding portion 212, optical / photon signals can preferably propagate in the core portion 210. For example, an optical mode can propagate in the core portion 210, and its electromagnetic field distribution 214 is confined to a local area related to the core portion 210. Figure 2C The spatial shape of the core portion 210 shown is only an example, and the core portion 210 in other embodiments can have various other shapes.

[0114] Figure 3A is a top view of a photon device 300 containing photon couplers (208a, 208b) and photon conditioner portions (108a, 108c) in various embodiments. In various embodiments, Figure 3B is Figure 3A a vertical cross-sectional view of the first conditioner portion 108a of the photon device 300, and Figure 3C is Figure 3A a vertical cross-sectional view of the first photon coupler 208a of the photon device. Figure 3A The vertical plane B - B' in Figure 3B refers to the first vertical plane, which defines the Figure 3A vertical cross-section shown. Figure 3C The vertical plane C - C' in

[0115] As Figure 3A shown, the photon device 300 can include a first input waveguide 104a1, a second input waveguide 104a2, a third input waveguide 104a3, and a fourth input waveguide 104a4. Similarly, the photon device 300 can include a first output waveguide 104b1, a second output waveguide 104b2, a third output waveguide 104b3, and a fourth output waveguide 104b4. The photon device 300 can further include a first photon coupler 208a, which mixes the first input photon signal received from the first input waveguide 104a1 and the second input photon signal received from the second input waveguide 104a2 to generate a first output photon signal and a second output photon signal, which are respectively provided to the first output waveguide 104b1 and the second output waveguide 104b2.

[0116] The photon device 300 may further include a second photon coupler 208b, which may mix a third input photon signal received from a third input waveguide 104a3 and a fourth input photon signal received from a fourth input waveguide 104a4 to generate a third output optical signal and a fourth output optical signal and provide them to a third output waveguide 104b3 and a fourth output waveguide 104b4 respectively. The photon device 300 may be similar to Figure 2B the optical switch 200b. In this regard, the photon device 300 may further include a first adjuster portion 108a, which may change the amplitude or phase of a first output photon signal received from a first output waveguide 104b1 and generate a third input photon signal to provide to the third input waveguide 104a3.

[0117] However, compared with Figure 2B the optical switch 200b, the photon device 300 may omit Figure 2B the second adjuster portion 108b located between the second output waveguide 104b2 and the fourth output waveguide 104a4 in Figure 3A . In this regard, the second output waveguide 104b2 may be photon-coupled to the fourth input waveguide 104a4, for example, by providing a single waveguide (104b2, 104a4) to photon-couple the first photon coupler 208a to the second photon coupler 208b, as Figure 3A shown. In addition, compared with Figure 2B the optical switch 200b, the photon device 300 may include a third adjuster portion 108c, which may control the amplitude and phase of a first optical signal provided by the first input waveguide 104a1. Other embodiments may provide various other settings of the photon device (such as the photon device 400), as described in conjunction with Figures 4 to 6B the content described below.

[0118] As Figure 3B shown, the first adjuster portion 108a may be arranged as a semiconductor-insulator-capacitor structure. In this regard, the first adjuster portion 108a may include a first end 302a, which includes a first semiconductor material doped with a dopant of a first conduction type; and a second end 302b, which includes a second semiconductor material doped with a dopant of a second conduction type. The first adjuster portion 108a may further include a dielectric layer 304 to separate the first end 302a and the second end 302b. In various embodiments, the composition of the first end 302a may be n-type polysilicon, the second end 302b may include p-type silicon, and the dielectric layer 304 includes silicon oxide. As Figure 3B shown, the first end 302a may be electrically connected to a first electrical contact 306a, and the second end 302b may be electrically connected to a second electrical contact 306b.

[0119] The first end 302a, the second end 302b, and the dielectric layer 304 may each have a slab geometry extending along the length direction (i.e., the x-direction), the width direction (i.e., the y-direction), and the thickness direction (i.e., the z-direction). As Figure 3A shown, the first output waveguide 104b1 and the third output waveguide 104a3 may be optically coupled to the first adjuster portion 108a. In this regard, the first adjuster portion 108a may include an overlapping region (308), and the first end 302a, the second end 302b, and the dielectric layer 304 in the overlapping region (308) overlap in a plan view along the thickness direction (i.e., along the z-direction). In this way, the overlapping region (308) may form a coupled waveguide component 308, which may couple the first output waveguide 104b1 and the third input waveguide 104a3. In this regard, the first output waveguide 104b1 may extend out of the plane of the figure along the x-axis, and the third input waveguide 104a3 may extend into the plane of the figure along the x-direction.

[0120] The coupled waveguide component 308 (such as the overlapping region) may support an optical mode propagating in the length direction (i.e., along the z-direction into the plane of the figure). As Figure 3B shown, the electromagnetic field distribution 214 of the optical mode spatially overlaps with the first end 302a, the second end 302b, and the dielectric layer 304. In this way, the electromagnetic field can be optically coupled from the first output waveguide 104b1 to the third input waveguide 104a3 via the coupled waveguide component 308.

[0121] The first adjuster portion 108a may be configured as an electro-optic device, which may adjust the amplitude or phase of the electromagnetic field distribution. In this way, the effective refractive index and the absorption coefficient of the first adjustment portion 108a may be a function of the voltage difference applied between the first end 302a and the second end 302b. In this regard, the first end 302a, the second end 302b, and the dielectric layer 304 may form an electrically adjustable capacitor structure having a p-n junction.

[0122] According to the free carrier dispersion effect in silicon, the carrier distribution in the first end 302a and the second end 302b can be changed by the bias voltage to change the optical properties of the coupled waveguide component 308. For example, a forward bias voltage can inject carriers into the p-n junction to reduce the size of the depletion region. A reverse bias voltage can deplete carriers and increase the size of the depletion region. In one configuration, the first adjuster portion 108a may be operated in a reverse bias (i.e., depletion mode) to have a low concentration of free carriers, so that the coupled waveguide component 308 has a lower optical absorption. In other embodiments, the first adjuster portion 108a may be operated in a forward bias.

[0123] As Figure 3CAs shown, the first photon coupler 208a may also include an electro-optic device, whose refractive index and absorption coefficient may be a function of the applied bias voltage. In this regard, the first photon coupler 208a may include a first end 302a, which has a first slab geometry extending along the length direction (i.e., the x direction in the plane of the figure entering), the width direction (i.e., the y direction), and the thickness direction (i.e., the z direction). The first photon coupler 208a may further include a second end (302b1, 302b2), which has a first component 302b1 and a second component 302b2. The first component 302b1 and the second component 302b2 may not be connected to each other. The first component 302b1 and the second component 302b2 may each include a second slab geometry extending along the length direction (i.e., the x direction in the plane entering), the width direction (i.e., the y direction), and the thickness direction (i.e., the z direction). In addition as shown, the first component 302b1 and the second component 302b2 may be separated from each other along the width direction. The first photon coupler 208a may further include a dielectric layer 304 to separate the first end 302a and the second end (302b1, 302b2).

[0124] As Figure 3B In the first adjuster portion 108a as such, the first photon coupler 208a may be arranged as a semiconductor-insulator-capacitor structure. In this way, the first end 302a may include a first semiconductor material doped with dopants of a first conductivity type, and the second end (302b1, 302b2) may include a second semiconductor material doped with dopants of a second conductivity type. In various embodiments, the composition of the first end 302a may be n-type polysilicon, the second end (302b1, 302b2) may include p-type silicon, and the dielectric layer 304 includes silicon oxide. As Figure 3C shown, the first end 302a may be electrically connected to a first electrical contact 306a, the first component 302b1 of the second end (302b1, 302b2) may be electrically connected to a second electrical contact 306b1, and the second component 302b2 of the second end (302b1, 302b2) may be electrically connected to a third electrical contact 306b2.

[0125] The first photon coupler 208a may further include a first coupled waveguide component 308a, which is optically coupled to the first input waveguide 104a1 and the first output waveguide 104b1; and a second coupled waveguide component 308b, which is optically coupled to the second input waveguide 104a2 and the second output waveguide 104b2 (see Figure 2B ). In this regard, the first input waveguide 104a1 may extend out of the Figure 3C plane along the x direction, and the first output waveguide 104b1 may extend into the plane of the figure along the x direction. Similarly, the second input waveguide 104a2 may extend out of the Figure 3Cplane, and the second output waveguide 104b2 can extend along the x direction into the plane of the figure.

[0126] The first coupling waveguide component 308a (see Figure 2B and Figure 3C ) can extend along the longitudinal direction (i.e., the x direction into the Figure 3C plane), and the longitudinal direction is parallel to the optical propagation direction. The first coupling waveguide component 308a can form a first overlapping region (308a), where the first end 302a in the first overlapping region, the first component 302b1 of the second end (302b1, 302b2), and the dielectric layer 304 overlap in a plan view along the thickness direction (i.e., along the z direction). Similarly, the second coupling waveguide component 308b can extend along the longitudinal direction (i.e., the x direction into the Figure 3C plane) and can form a second overlapping region (308b), where the first end 302a in the second overlapping region, the second component 302b2 of the second end (302b1, 302b2), and the dielectric layer 304 overlap in a plan view along the thickness direction (i.e., along the z direction). In addition, as Figure 3C shown, the first component 302b1 and the second component 302b2 of the second end (302b1, 302b2) can be separated from each other along the width direction (i.e., along the y direction).

[0127] The first photon coupler 208a can receive a first optical signal from the first input waveguide 104a1 and a second optical signal from the second input waveguide 104a2. Due to the phenomenon of evanescent coupling, the electromagnetic fields associated with two or more of the first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2 can have a spatially overlapping electromagnetic field distribution 214. In this way, in the coupling region 209 including the first overlapping region (308a) and the second overlapping region (308b) (see Figure 2B and Figure 3C ), the electromagnetic energies associated with the first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2 can be coupled to each other. In summary, various embodiments can design the coupling length to be an integer multiple of the wavelength plus a quarter wavelength to configure the photon device 300 as a first 50 / 50 beam splitter.

[0128] As described in conjunction with Figure 2B the above content, when Figure 3AWhen the photon device 300 is set as the first 50 / 50 beam splitter, 50% of the first optical signal can be introduced into the first output waveguide 104b1, while the other 50% of the second optical signal can be introduced into the second output waveguide 104b2. At the same time, 50% of the second optical signal can be introduced into the first output waveguide 104b1, while the other 50% of the second optical signal can be introduced into the second output waveguide 104b2. In this consideration, the first optical signal and the second optical signal between the first output waveguide 104b1 and the second output waveguide 104b2 can be equally split.

[0129] Generally speaking, the photon device 300 can be set to couple different electromagnetic energy mixing ratios between the first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2. In this consideration, the electromagnetic energy coupled between the first input waveguide 104a1 and the second output waveguide 104b2 (and similarly the electromagnetic energy coupled between the second input waveguide 104a2 and the first output waveguide 104b1) depends on the effective coupling length of the coupling region 209 (i.e., the effective length along the propagation direction of the first overlapping region such as the first coupling waveguide component 308a and the second overlapping region such as the second coupling waveguide component 308b). In this consideration, the energy mixing ratio coupled between various input and output waveguides is an oscillating function (such as a sine function) of the effective coupling length.

[0130] For the fixed effective refractive index of the first photon coupler 208a, the physical lengths of the first overlapping region (308a) and the second overlapping region (308b) will determine the coupling length. Similarly, for the fixed lengths of the first overlapping region (308a) and the second overlapping region (308b), the effective refractive index of the first photon coupler 208a will determine the effective coupling length. In this way, the product of the effective refractive index and the physical length of the coupling region 209 is the effective coupling length.

[0131] The effective coupling length of the first photon coupler 208a can be set as a function of the applied voltage. In this consideration, for the fixed physical lengths of the first overlapping region (308a) and the second overlapping region (308b), the effective refractive index can be changed, such as in combination with Figure 3BThe content described above. In this way, the effective coupling length can be made a function of the bias voltage applied between the first end 302a and the second ends (302b1, 302b2). For example, a first percentage of the first electromagnetic energy can be coupled from the first input waveguide 104a1 into the second output waveguide 104b2, and a second percentage of the second electromagnetic energy can be coupled from the second input waveguide 104a2 into the first output waveguide 104b1, such that the first percentage of the first electromagnetic energy and the second percentage of the second electromagnetic energy are functions of the applied voltage. For example, in one embodiment, the first percentage and the second percentage can each be between 49% and 51%. Other embodiments can achieve various other voltage-adjustable percentages. In a particular embodiment of high symmetry, the first percentage and the second percentage can be the same. However, due to manufacturing tolerances, the first percentage and the second percentage need not be the same.

[0132] Generally, the effective coupling length can increase when the applied voltage has a first polarity and can decrease when the applied voltage has a second polarity, and the first polarity is opposite to the second polarity. Thus, the first photon coupler 208a can be arranged such that a given range of applied voltage (such as negative to positive, positive to positive, or negative to negative) can produce a corresponding range of mixing ratios of the electromagnetic energy coupled between the first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2. The second photon coupler 208b can be arranged in a manner similar to that of the first photon coupler 208a. In this way, the second photon coupler 208b can also include an electro-optic device that can determine the mixing ratio of the third input photon signal received from the third input waveguide 104a3 and the fourth input photon signal received from the fourth input waveguide 104a4 based on the voltage applied to the second photon coupler 208b.

[0133] Figure 4 is a top view of another photon device 400 of various embodiments, which includes photon couplers (208a, 208b) and photon adjuster portions (108a, 108b, 108c, 108d). The photon device 400 can be similar to the photon device 300 but can further include a second adjuster portion 108b. As with Figure 2B the content described above, the second adjuster portion 108b can be optically connected between the second output waveguide 104b2 and the fourth input waveguide 104a4. In this way, the second adjuster portion 108b can change the amplitude or phase of the second output optical signal received from the second output waveguide 104b2 to generate a fourth input optical signal for providing to the fourth output waveguide 104b4. Additionally, compared with the Figure 3A photon device 300 of Figure 4The photon device 400 may include a fourth adjuster portion 108d. As shown, the fourth adjuster portion 108d may be arranged to control the amplitude and / or phase of the second input signal provided by the second input waveguide 104a2. The second adjuster portion 108b and the fourth adjuster portion 108d may each include an electro-optic device, such as those described above in conjunction with Figure 3B the content described above.

[0134] Figure 5A , Figure 5B , Figure 6A , and Figure 6B are cross-sectional views of other photon adjusters 108 and other photon couplers 208 in various embodiments. Figure 5A The photon adjuster 108 of Figure 3B may be similar to the photon adjuster 108 of Figure 3B . However, compared with the first adjuster portion 108a of Figure 3B , the first end 302a may be arranged to include a ridge waveguide structure 502. The ridge waveguide structure 502 may be arranged to confine the electromagnetic field distribution 214 to be more local than the corresponding electromagnetic field distribution 214 of the first adjuster portion 108a of Figure 5A . In this way, the spatial extent of the coupled waveguide component 308 of the photon adjuster 108 of Figure 3B in the width direction (i.e., the y-direction) is smaller than the spatial extent of the coupled waveguide component 308 of the photon adjuster 108 of

[0135] As Figure 5B shown, the first end 302a of the photon coupler 208 may include a first ridge waveguide structure 502a and a second ridge waveguide structure 502b. The first ridge waveguide structure 502a and the second ridge waveguide structure 502b may each be arranged to achieve a predetermined spatial profile of the electromagnetic field distribution 214 in the first coupled waveguide component 308a and the second coupled waveguide component 308b, respectively. As in Figure 5A the first photon coupler 208a, the first component 302b1 and the second component 302b2 of the second end (302b1, 302b2) may be physically separated from each other but close enough to each other so that the individual electromagnetic field distributions 214 can overlap with each other. In this regard, the evanescent fields of the first component 302b1 and the second component 302b2 can overlap with each other, and thus evanescent coupling between the first coupled waveguide component 308a and the second coupled waveguide component 308b can occur, as described in detail above in conjunction with Figure 2B the content described above.

[0136] As Figure 6A and Figure 6B shown, the other photon adjusters 108 and the photon coupler 208 may have individual settings of different electrical contacts. In Figure 6AFor example, a first electrical contact 306a can be formed to directly contact the ridge waveguide structure 502. Similarly, other photon couplers 208 can have a first electrical contact 306a1 and a second electrical contact 306a2 (compared to Figure 3C the single first electrical contact 306a of the photon coupler 208). As Figure 6B shown, the first electrical contact 306a1 and the second electrical contact 306a2 can be respectively connected to a first ridge waveguide structure 502a and a second ridge waveguide structure 502b. Other embodiments can provide other arrangements of a first end 302a, second ends (302b, 302b1, 302b2), and electrical contacts (306a, 306a1, 306a2, 306b1, 306b2).

[0137] Figures 7A to 7K In various embodiments, Figure 7L is a vertical cross-sectional view of an intermediate structure (700a to 700k) used to form the photon coupler 208 shown. The intermediate structure 700a can include a layer 302bL of semiconductor material, which can be used to form second ends (302b1, 302b2). For example, the layer 302bL can be the topmost layer of a silicon substrate or the silicon layer of a silicon-on-insulator substrate. The layer 302bL can be undoped or a p-type doped layer 302bL. It can be formed from Figure 7A the intermediate structure 700a to form Figure 7B the intermediate structure 700b, such as etching the layer 302bL to remove a portion of the layer 302bL. The final intermediate structure 700b can include second ends (302b1, 302b2) with a separated first component 302b1 and second component 302b2. In this regard, a patterned photoresist (not shown) can be formed on the semiconductor layer 302bL to mask corresponding regions of the unetched regions (for forming the first component 302b1 and the second component 302b2 of the second ends (302b1, 302b2)). Then an anisotropic etching process can be performed to etch the unmasked central region. Then the patterned photoresist can be removed, and the removal method can be ashing or dissolution by a solvent.

[0138] Next, a covering material can be formed in the region where the semiconductor layer 302bL is etched. In this way, a covering portion 212 can be formed. The covering portion 212 can be formed by depositing a dielectric material and then performing a planarization process such as chemical mechanical planarization. In one embodiment, the covering portion 212 can include silicon oxide. Other embodiments can include other oxides or other types of dielectric materials such as polymers. It can be formed from Figure 7B the intermediate structure 700b to form Figure 7Can intermediate structure 700c, such as a first component 302b1 and a second component 302b2 selectively doped at the second ends (302b1, 302b2). In this regard, an ion implantation process can be performed to introduce p-type dopants into the first component 302b1 and the second component 302b2 of the second ends (302b1, 302b2). Then, additional dielectric material can be deposited on the final structure to form Figure 7D an intermediate structure 700d. In this regard, after depositing the additional dielectric material, a planarization process such as chemical mechanical planarization can be performed to form a planar surface of the cover portion 212.

[0139] from Figure 7D the intermediate structure 700d to form Figure 7E an intermediate structure 700e, such as depositing another semiconductor layer 302aL on the upper surface of the cover portion 212. In this regard, the semiconductor layer 302aL can be a semiconductor material suitable for forming the first end 302a. For example, in a specific embodiment, the semiconductor layer 302aL can be polysilicon, and its deposition method can adopt a conformal deposition method such as chemical vapor deposition. Other embodiments can include other semiconductor layers 302aL suitable for forming the first end 302a, and their deposition methods can adopt appropriate individual methods.

[0140] from Figure 7E the intermediate structure 700e to form Figure 7F an intermediate structure 700f, such as performing an etching step to remove a portion of the semiconductor layer 302aL. The remaining intermediate structure 700f can include the first end 302a. In this regard, a patterned photoresist (not shown) can be formed on the semiconductor layer 302aL to mask the corresponding regions of the regions not to be etched (for forming the first end 302a). Then, an anisotropic etching process is performed to etch the unmasked regions. Then, the patterned photoresist can be removed, such as by ashing or dissolving with a solvent. From Figure 7F the intermediate structure 700f to form Figure 7G an intermediate structure 700g, such as depositing additional dielectric material to increase the thickness of the cover portion 212. Then, a planarization process such as chemical mechanical planarization can be performed to remove the upper surface of the additional dielectric layer above the upper surface of the first end 302a, thereby exposing the upper surface of the first end 302a. From Figure 7G the intermediate structure 700g to form Figure 7H an intermediate structure 700h, such as performing a selective deposition process such as using ion implantation to introduce n-type dopants into the first end 302a.

[0141] from Figure 7H the intermediate structure 700h to form Figure 7IThe intermediate structure 700i, for example, deposits additional dielectric material such as silicon oxide on the intermediate structure 700h to increase the thickness of the covering portion 212. Then, a planarization process such as chemical mechanical planarization can be performed to remove a part of the additional dielectric layer to form a flat upper surface of the covering portion and expose the upper surface of the first end 302a. Starting from Figure 7I the formation of the intermediate structure 700i Figure 7J The method for forming the intermediate structure 700j of can be to perform an etching process to generate contact via openings 702 in the covering portion 212.

[0142] In this regard, a lithography technique can be used to form a patterned photoresist (not shown) on the upper surface of the intermediate structure 700i. Then, the patterned photoresist is used as an etching mask to protect the surface portion of the covering portion 212 that does not need to be etched. The unmasked portion of the patterned photoresist can correspond to the region where the contact via openings 702 are etched later. As shown in the figure, the etching process can be performed until the upper surfaces of the first end 302a and the first component 302b1 and the second component 302b2 of the second end (302b1, 302b2) are exposed.

[0143] Then, starting from Figure 7J the formation of the intermediate structure 700j Figure 7K the intermediate structure 700k of can be formed, for example, by performing a selective doping process to generate an n-type well 704a and a p-type well 704b. In this regard, a first ion implantation process can be performed to introduce additional n-type dopants into the first end 302a through the corresponding contact via openings 702 to form the n-type well 704a. Similarly, a second ion implantation process can be performed to introduce additional p-type dopants into the first component 302b1 and the second component 302b2 of the second end (302b1, 302b2) through the corresponding contact via openings 702 to form the p-type well 704b.

[0144] Then, starting from Figure 7K the formation of the intermediate structure 700k Figure 7L the photon coupler 208 of can be formed, for example, by depositing a conductive material in the contact via openings 702 to form a first electrical contact 306a, a second electrical contact 306b1, and a third electrical contact 306b2. In this regard, the conductive material can be a combination of a metal liner (such as metal nitride or metal carbide) and a metal filling material. The metal liners can each include titanium nitride, tantalum nitride, tungsten nitride, titanium carbide, or tungsten carbide, and the metal filling material portions can each include tungsten, copper, aluminum, cobalt, ruthenium, molybdenum, tantalum, titanium, alloys thereof, and / or combinations of the above. Other suitable metal liners and metal filling materials within the scope of the embodiments of the present invention can also be used. Then, a planarization process such as chemical mechanical planarization can be performed to remove the remaining portion of the conductive material above the upper surface of the covering portion 212.

[0145] Figure 8 FIG. 800 is a flow chart of steps of a method 800 for forming a photon coupler (208, 208a, 208b) in various embodiments. In step 802 of method 800, forming a first input waveguide 104a1 and a second input waveguide 104a2 may be included. In step 804 of method 800, forming a first output waveguide 104b1 and a second output waveguide 104b2 may be included. As detailed below, in steps 806 and 808 of method 800, forming a coupling region 209 may be included, which includes electro-optic devices (302a, 304, 302b), and the refractive index of the electro-optic devices is a function of an applied voltage, so that the electromagnetic fields associated with two or more of the first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2 in the coupling region 209 overlap each other.

[0146] In this regard, step 806 of method 800 may further include forming a first coupled waveguide component 308a, which is optically coupled to the first input waveguide 104a1 and the first output waveguide 104b1. Step 808 of the method may further include forming a second coupled waveguide component 308b, which is optically coupled to the second input waveguide 104a2 and the second output waveguide 104b2. Steps 806 and 808 may be performed so that the first coupled waveguide component 308a and the second coupled waveguide component 308b each include electro-optic devices (302a, 304, 302b).

[0147] The method 800 of forming the coupling region 209 containing the optoelectronic devices (302a, 304, 302b) may further include forming a first end 302a including n-type polysilicon; forming second ends (302b1, 302b2) including p-type silicon; and forming a dielectric layer 304 to separate the first end 302a from the second ends (302b1, 302b2). In other embodiments, the method 800 may alternatively further include forming a first end 302a including p-type silicon; and forming second ends (302b1, 302b2) including n-type silicon. The method 800 may further include forming a first coupling waveguide component 308a extending along a length direction (i.e., the x direction), and the length direction being parallel to the optical propagation direction, such that the first coupling waveguide component 308a becomes a first overlapping region (308a), wherein the first end 302a, the second ends (302b1, 302b2), and the dielectric layer 304 in the first overlapping region overlap in a plan view along a thickness direction (i.e., the z direction), and the thickness direction is perpendicular to the length direction (i.e., the x direction). The method 800 may further include forming a second coupling waveguide component 308b extending along the length direction (i.e., the x direction), such that the second coupling waveguide component 308b becomes a second overlapping region (308b), wherein the first end 302a, the second ends (302b1, 302b2), and the dielectric layer 304 in the second overlapping region overlap in a plan view along the thickness direction (i.e., the z direction). The method 800 may further include forming the first coupling waveguide component 308a and the second coupling waveguide component 308b separated from each other in a width direction (i.e., the y direction), and the width direction (i.e., the y direction) being perpendicular to the length direction (i.e., the x direction) and the thickness direction (i.e., the z direction). In a specific embodiment, the method 800 may include forming the first coupling waveguide component 308a and the second coupling waveguide component 308b to include ridge waveguide structures (502a, 502b).

[0148] According to all the figures and various embodiments of the present invention, a photon coupler (208, 208a, 208b) is provided. The photon coupler (208, 208a, 208b) may include a first input waveguide 104a1 and a second input waveguide 104a2, a first output waveguide 104b1 and a second output waveguide 104b2, and a coupling region 209. The coupling region 209 may be formed such that the electromagnetic fields associated with two or more of the first input waveguide 104a1, the second input waveguide 104a2, the first output waveguide 104b1, and the second output waveguide 104b2 overlap each other.

[0149] The optical couplers (208, 208a, 208b) may further include electro-optic devices (302a, 304, 302b) located in the coupling region (209) and including a refractive index, and the refractive index is a first function of an applied voltage. The coupling region 209 may include an effective coupling length along the optical propagation direction, and the effective coupling length is a second function of the product of the physical length of the coupling region 209 and the refractive index of the electro-optic devices (302a, 304, 302b). In this regard, the effective coupling length may be a function of the applied voltage because the effective coupling constant depends on the refractive index of the electro-optic devices (302a, 304, 302b). Additionally, the effective coupling length of various embodiments is such that the voltage can be adjusted to an integer multiple of the wavelength plus a quarter wavelength.

[0150] In various embodiments, a first percentage of the first electromagnetic energy may be coupled from the first input waveguide 104a1 to the second output waveguide 104b2, and a second percentage of the second electromagnetic energy may be coupled from the second input waveguide 104a2 to the first output waveguide 104b1, such that the first percentage of the first electromagnetic energy and the second percentage of the second electromagnetic energy are functions of an applied voltage. In a particular embodiment, the first percentage and the second percentage may each be between 41% and 59%. The effective coupling length when the applied voltage has a first polarity may increase, while the effective coupling length when the applied voltage has a second polarity may decrease, and the first polarity and the second polarity are opposite.

[0151] In various embodiments, the electro-optic devices (302a, 304, 302b) may include a first end 302a that includes a first semiconductor material doped with a dopant of a first conductivity type; second ends (302b1, 302b2) that include a second semiconductor material doped with a dopant of a second conductivity type; and a dielectric layer 304 that separates the first end 302a from the second ends (302b1, 302b2). In a particular embodiment, the dielectric layer 304 may include silicon oxide, the first end 302a may include n-type polysilicon, and the second ends (302b1, 302b2) may include p-type silicon. In other embodiments, the first end 302a may include p-type silicon, and the second end 302b may include n-type silicon. The coupling region 209 may further include: a first coupling waveguide component 308a that is optically coupled to the first input waveguide 104a1 and the first output waveguide 104b1; and a second coupling waveguide component 308b that is optically coupled to the second input waveguide 104a2 and the second output waveguide 104b2.

[0152] The first coupled waveguide component 308a extends along the length direction (i.e., the x direction) and forms a first overlapping region (308a), and the length direction is parallel to the optical propagation direction. Among them, the first end 302a, the second ends (302b1, 302b2) in the first overlapping region overlap with the dielectric layer 304 in a plan view along the thickness direction (i.e., the z direction), and the thickness direction is perpendicular to the length direction (i.e., the x direction). The second coupled waveguide component 308b extends along the length direction (i.e., the x direction) and forms a second overlapping region (308b). Among them, the first end 302a, the second ends (302b1, 302b2) in the second overlapping region overlap with the dielectric layer 304 in a plan view along the thickness direction (i.e., the z direction). In addition, the first coupled waveguide component 308a and the second coupled waveguide component 308b can be separated from each other along the width direction (i.e., the y direction), and the width direction (i.e., the y direction) is perpendicular to the length direction (i.e., the x direction) and the thickness direction (i.e., the z direction).

[0153] In various embodiments, the first end 302a includes a first plate geometry extending along the length direction (i.e., the x direction), the width direction (i.e., the y direction), and the thickness direction (i.e., the z direction), while the second ends (302b1, 302b2) include a first component 302b1 and a second component 302b2 that are not connected to each other. Among them, the first component 302b1 and the second component 302b2 each include a second plate geometry extending along the length direction (i.e., the x direction), the width direction (i.e., the y direction), and the thickness direction (i.e., the z direction), so that the first component 302b1 and the second component 302b2 are separated from each other along the width direction (i.e., the y direction). The first end 302a can be electrically connected to the first electrical contact 306a, the first component 302b1 of the second ends (302b1, 302b2) can be electrically connected to the second electrical contact 306b1, and the second component 302b2 of the second ends (302b1, 302b2) can be electrically connected to the third electrical contact 306b2.

[0154] In addition, according to all the diagrams and various embodiments of the present invention, a photon device (300, 400) is provided. The photon device (300, 400) may include a first input waveguide 104a1, a second input waveguide 104a2, a third input waveguide 104a3, a fourth input waveguide 104a4, a first output waveguide 104b1, a second output waveguide 104b2, a third output waveguide 104b3, and a fourth output waveguide 104b4. The photon device (300, 400) may further include a first photon coupler 208a that mixes a first input photon signal received from the first input waveguide 104a1 and a second input photon signal received from the second input waveguide 104a2 to generate a first output photon signal and a second output photon signal and provide them to the first output waveguide 104b1 and the second output waveguide 104b2 respectively. The photon device (300, 400) may further include a second photon coupler 208b that mixes a third input photon signal received from the third input waveguide 104a3 and a fourth input photon signal received from the fourth input waveguide 104a4 to generate a third output photon signal and a fourth output photon signal and provide them to the third output waveguide 104b3 and the fourth output waveguide 104b4 respectively.

[0155] The photon device (300, 400) may further include a first adjuster portion 108a that changes the amplitude or phase of the first output photon signal to generate a third input photon signal and provide it to the third input waveguide 140a3. In this regard, at least one of the first photon coupler 208a and the second photon coupler 208b includes an electro-optic device (302a, 304, 302b) that determines the mixing ratio of the first input photon signal and the second input photon signal, or the mixing ratio of the third input photon signal and the fourth input photon signal, based on the voltage applied to the first photon coupler 208a or the second photon coupler 208b respectively. In a particular embodiment, the first output waveguide 104b1 may be photon-coupled to the fourth input waveguide 104a4. In other embodiments, the photon device (300, 400) may further include a second adjuster portion 108b that adjusts the amplitude or phase of the second output optical signal received from the second output waveguide 104b2 to generate a fourth input optical signal and provide it to the fourth input waveguide 104a4.

[0156] In other embodiments, the photon device (300, 400) may include at least one additional adjuster portion (108c, 108d) that controls the amplitude or phase of the first input photon signal or the second input photon signal. In various embodiments, the first photon coupler 208a and the second photon coupler 208b may determine the mixing ratio of the input signals to generate individual output signals such that the individual mixing ratios are functions of the voltages applied to the first photon coupler 208a and the second photon coupler 208b respectively.

[0157] As described above, the advantage of the photon couplers (208, 208a, 208b) included in the embodiments is to provide electro-optic devices (302a, 304, 302b) that can adjust the effective coupling length based on the voltage applied to the electro-optic devices (302a, 304, 302b). In this regard, the effective coupling length can determine the mixing ratio of the first electromagnetic energy transmitted from the first input waveguide 104a1 to the second output waveguide 104b2 relative to the second electromagnetic energy transmitted from the second input waveguide 104a2 to the first output waveguide 104b1. For example, by designing the effective coupling length to be an integer multiple of the wavelength plus a quarter of the wavelength, the photon couplers of the embodiments can be designed to operate as a 50 / 50 beam splitter without applying a voltage. However, due to manufacturing tolerances, the photon couplers (208, 208a, 208b) may be defective, resulting in an error in the mixing ratio of the transmitted electromagnetic energy.

[0158] Therefore, although the photon couplers (208, 208a, 208b) are designed as 50 / 50 beam splitters, the photon couplers (208, 208a, 208b) can actually act as 49 / 51 beam splitters (or 41 / 59 beam splitters, or the like) due to imperfections. However, by providing the electro-optic devices (302a, 304, 302b), a bias voltage can be appropriately applied to correct the mixing ratio. In this regard, the voltage-dependent effective coupling length can be adjusted to correct the 49 / 51 performance (or other percentage errors) with the bias voltage to achieve the desired 50 / 50 beam splitter performance. In other embodiments, the electro-optic devices (302a, 304, 302b) can be used to achieve various mixing ratios in other applications. In this way, the photon couplers (208, 208a, 208b) of the embodiments can adjust the applied voltage to easily correct the errors in the device performance.

[0159] Those of ordinary skill in the art should understand that the present invention can be used as a basis to design and vary other processes and structures to achieve the same purpose and / or the same advantages as the above embodiments. Those of ordinary skill in the art should also understand that these equivalent replacements do not depart from the spirit and scope of the present invention and can be changed, replaced, or modified without departing from the spirit and scope of the present invention.

Claims

1. A photon coupler, comprising: a first input waveguide and a second input waveguide; a first output waveguide and a second output waveguide; a coupling region, wherein electromagnetic fields associated with two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide in the coupling region overlap; as well as An electro-optic device is located in the coupling region and includes a refractive index that is a first function of an applied voltage.

2. The photonic coupler of claim 1, wherein the coupling region comprises an effective coupling length along an optical propagation direction, and the effective coupling length is a second function of the product of a physical length of the coupling region and the refractive index of the electro-optical device.

3. The photonic coupler of claim 2, wherein the effective coupling length is a function of the applied voltage and depends on the refractive index of the electro-optical device; and The effective coupling length is a voltage adjustable integer multiple of the wavelength plus a quarter wavelength.

4. The photonic coupler of claim 3, wherein a first percentage of a first electromagnetic energy is coupled from the first input waveguide into the second output waveguide, and a second percentage of a second electromagnetic energy is coupled from the second input waveguide into the first output waveguide, and The first percentage of the first electromagnetic energy and the second percentage of the second electromagnetic energy are functions of the applied voltage.

5. A photonic device comprising: a first input waveguide, a second input waveguide, a third input waveguide, and a fourth input waveguide; a first output waveguide, a second output waveguide, a third output waveguide, and a fourth output waveguide; a first photon coupler for mixing a first input photon signal received from the first input waveguide and a second input photon signal received from the second input waveguide to generate a first output photon signal and a second output photon signal and providing them to the first output waveguide and the second output waveguide respectively; a second photon coupler for mixing a third input photon signal received from the third input waveguide and a fourth input photon signal received from the fourth input waveguide to generate a third output photon signal and a fourth output photon signal and provide them to the third output waveguide and the fourth output waveguide respectively; as well as a first adjuster section, which changes the amplitude or phase of the first output photon signal to generate the third input photon signal and provides it to the third input waveguide, At least one of the first photon coupler and the second photon coupler includes an electro-optical device, which determines the mixing ratio of the first input photon signal and the second input photon signal, or the mixing ratio of the third input photon signal and the fourth input photon signal based on the voltage applied to the first photon coupler or the second photon coupler respectively.

6. The photonic device of claim 5, wherein the first output waveguide is photonically coupled to the fourth input waveguide.

7. The photonic device of claim 5, further comprising: A second adjuster portion changes the amplitude or phase of the second output photon signal received from the second output waveguide to generate the fourth output photon signal to be provided to the fourth input waveguide.

8. A method for forming a photon coupler, comprising: forming a first input waveguide and a second input waveguide; forming a first output waveguide and a second output waveguide; as well as forming a coupling region including an electro-optic device having a refractive index that is a function of an applied voltage, The electromagnetic fields associated with two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide in the coupling region overlap with each other.

9. The method for forming a photon coupler as claimed in claim 8, wherein the step of forming the coupling region further comprises: forming a first coupling waveguide component optically coupled to the first input waveguide and the first output waveguide; as well as forming a second coupling waveguide component optically coupled to the second input waveguide and the second output waveguide, The first coupling waveguide component and the second coupling waveguide component each include the electro-optical device.

10. The method for forming a photon coupler as claimed in claim 9, wherein the step of forming the coupling region further comprises: forming a first end comprising n-type polysilicon; forming a second end comprising p-type silicon; as well as A dielectric layer is formed to separate the first end and the second end.

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