Thermo-optic phase shifter with partial suspension structure

Abstract

Thermo-optical phase shifter having a partially suspended structure. Disclosed embodiments relate to a thermo-optical phase shifter and a method of adjusting the speed and efficiency of intensity modulation using the thermo-optical phase shifter. The thermo-optical phase shifter includes a substrate defining at least one trench within a portion of the substrate and a buried oxide (BOX) layer formed over the substrate. The BOX layer is disposed along a length of the substrate. The thermo-optical phase shifter includes a waveguide disposed on the BOX layer for guiding an input signal, the substrate extending partially outward on either side of the waveguide. The method includes receiving an input signal by the thermo-optical phase shifter, adjusting a voltage applied to a heater of the thermo-optical phase shifter, and transmitting an output signal from the thermo-optical phase shifter.

Description

Technical Field

[0001] The present invention generally relates to a thermo-optic phase shifter having a suspension structure. The thermo-optic phase shifters of the present invention balance efficiency and speed to meet different application requirements. These thermo-optic phase shifters can be used in all fields of photonic devices and integrated circuits involving phase shift or modulation, including but not limited to silicon photonics, near / mid-infrared, visible light, and microwave photonics. In particular, these phase shifters can be used as key components for different applications such as quantum computing, LiDAR (Light Detection And Ranging), and sensors, improving speed, thermal insulation, and power efficiency. The present invention also relates to a method for adjusting the speed and efficiency of intensity modulation.

Background Art

[0002] Generally, thermo-optic phase shifters are used for phase modulation or intensity modulation of optical signals. The thermo-optic phase shifter changes the phase and intensity of the input optical signal based on the input optical signal and the characteristics of the thermo-optic phase shifter, and transmits the output optical signal. Thermo-optic phase shifters generally have low loss, simple manufacturing, and power efficiency, and are applied in a wide range of fields such as quantum computing, optical parametric amplifiers (OPAs), various sensors and switching applications, advanced communications, and neural networks.

[0003] The thermo-optic phase shifter has a composite body having an optical waveguide, a p-type region, and an n-type region formed on a silicon substrate. The optical waveguide is disposed between the p-type region and the n-type region. Further, the thermo-optic phase shifter has a heater, a core including the silicon substrate, and a cladding layer disposed on the silicon substrate.

[0004] In the operation of a thermo-optic phase shifter, its overall performance depends primarily on two main characteristics: power efficiency and rise / fall time constant limitations. These two characteristics depend on the heat dissipation of the thermo-optic phase shifter and differ based on changes in its heat dissipation.

[0005] Existing thermo-optic phase shifters are primarily of two types, as shown in Figures 1A and 1B. Figure 1A shows a first type of thermo-optic phase shifter commonly used for different applications. The first type of thermo-optic phase shifter has a substrate 102, a buried oxide (BOX) layer 104, a waveguide 106, a heater 108, and cladding 110. In Figure 1B, the suspension region is arranged along the entire structure. The thermo-optic phase shifter in Figure 1B has low efficiency and low power consumption at high speeds. Figure 1B shows a second type of thermo-optic phase shifter with a trench 112 in the substrate 114. The second type of thermo-optic phase shifter also has a BOX layer 116, a waveguide 118, a heater 120, and cladding 122. The second type of thermo-optic phase shifter in Figure 1B is high efficiency and low speed.

[0006] The second type of thermo-optic phase shifter, as shown in Figure 1B, offers improved power efficiency, while the first type of thermo-optic phase shifter, shown in Figure 1A, offers improved operating speed. The second type of thermo-optic phase shifter offers decreased power efficiency, while the first type of thermo-optic phase shifter offers decreased operating speed. However, none of the existing thermo-optic phase shifters offer the combined advantages of improved operating speed, improved thermal insulation, and improved power efficiency in a single thermo-optic phase shifter. [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, it is necessary to provide a thermo-optical phase shifter that solves the above problems and offers the combined advantages of improved operating speed, improved thermal insulation, and improved power efficiency. [Means for solving the problem]

[0008] Embodiments of the present disclosure relate to a thermo-optic phase shifter and a method for receiving an input signal and transmitting an output signal using the thermo-optic phase shifter. In an exemplary embodiment, the thermo-optic phase shifter includes a substrate defining at least one trench, each trench having the same length. Furthermore, the thermo-optic phase shifter includes a buried oxide (BOX) layer formed on the substrate and arranged along the length of the substrate. The thermo-optic phase shifter further includes a waveguide positioned on the BOX layer to guide the input signal, with the substrate defining the trenches extending partially outward on both sides of the waveguide.

[0009] In an exemplary embodiment, each of the trenches has a depth of 120 micrometers (μm).

[0010] In some embodiments, the substrate extends along the transverse axis of the waveguide.

[0011] In some embodiments, the thermo-optic phase shifter includes a heater positioned adjacent to the waveguide. The heater heats the waveguide.

[0012] In one embodiment, the thermo-optic phase shifter includes a cladding layer positioned along the length of the heater to cover the thermo-optic phase shifter. The cladding layer is configured to protect the thermo-optic phase shifter and separate light between the heater and the waveguide.

[0013] In some embodiments, each trench has a different duty cycle.

[0014] In one embodiment, the thermo-optical phase shifter has a silicon substrate. The substrate dissipates heat.

[0015] In other embodiments, the thermo-optic phase shifter includes a substrate defining a trench within a portion of the substrate, the trench having a predetermined length, and includes a BOX layer formed on the substrate, the BOX layer being positioned along the length of the substrate to cover the trench. The thermo-optic phase shifter includes a waveguide positioned on the BOX layer to guide an input signal, and the substrate extends partially outward on both sides of the waveguide.

[0016] In other embodiments, the trenches have a predetermined period of 120 micrometers (μm).

[0017] In some embodiments, the thermo-optic phase shifter includes a heater positioned adjacent to the waveguide. The heater is configured to heat the waveguide.

[0018] In other embodiments, the heater includes a plurality of heater elements arranged adjacent to the waveguide.

[0019] In an exemplary embodiment, a cladding layer is positioned along the length of the heater, covering and protecting the thermo-optic phase shifter. The cladding layer is configured to separate light between the heater and the waveguide.

[0020] In an exemplary embodiment, the BOX layer is made of silica to prevent light leakage into the substrate.

[0021] In some embodiments, the substrate is made of silicon, and the substrate dissipates heat.

[0022] In some embodiments, a method for adjusting the speed and efficiency of intensity modulation is disclosed. This method includes receiving an input signal by a thermo-optic phase shifter. The input signal is an optical signal. The thermo-optic phase shifter includes a substrate defining at least one trench, a BOX layer formed on the substrate, and a waveguide disposed on the BOX layer. The substrate extends partially outward on both sides of the waveguide. This method includes adjusting the voltage applied to the heater of the thermo-optic phase shifter. The thermo-optic phase shifter transmits an output signal. The output signal has a different phase from the input signal, and the phase difference is based on the change in the applied voltage.

Advantages of the Invention

[0023] The thermo-optic phase shifters of the present disclosure provide a combined advantage of improved speed, better thermal insulation, and improved power efficiency during the operation of one thermo-optic phase shifter. These phase shifters can be used as key components for different applications such as quantum computing, LiDAR, and sensors.

[0024] To understand the present disclosure more fully, reference is made to the following brief description in connection with the accompanying drawings and detailed description. Here, like reference numerals represent like parts.

Brief Description of the Drawings

[0025] [Figure 1A] The prior art showing an existing type of thermo-optic phase shifter. [Figure 1B] The prior art showing an existing type of thermo-optic phase shifter.

[0026] [Figure 2A] An exemplary diagram showing a photo-thermal phase shifter according to a first embodiment of the present disclosure. [Figure 2B] An exemplary diagram showing a photo-thermal phase shifter according to a first embodiment of the present disclosure.

[0027] [Figure 3A]This is an illustrative diagram showing a photothermal phase shifter according to a second embodiment of the present disclosure. [Figure 3B] This is an illustrative diagram showing a photothermal phase shifter according to a second embodiment of the present disclosure.

[0028] [Figure 4] This graph shows the power efficiency of a thermo-optical phase shifter according to the length of the heater.

[0029] [Figure 5] This is an illustrative flowchart illustrating a method for adjusting the speed and efficiency of intensity modulation using a thermo-optic phase shifter. [Modes for carrying out the invention]

[0030] First, while exemplary embodiments of one or more embodiments are shown below, it should be understood that the disclosed systems and methods can be carried out using any number of techniques, whether currently known or not. This disclosure should not be limited in any way to the exemplary embodiments, drawings, and techniques shown below, but can be modified within the scope of the appended claims, along with the entire scope of their equivalents.

[0031] The following concise definitions of terms apply throughout the application.

[0032] The terms “equipped with” and “included” (as well as other forms such as “equipped with,” “include,” and “included” should not be interpreted as limiting.

[0033] The phrases "in one embodiment" and "according to one embodiment" generally mean that a particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present invention, and may be included in two or more embodiments of the present invention (importantly, such phrases do not necessarily refer to the same embodiment).

[0034] The use of the terms “exemplary” or “example” should be understood to refer to non-limiting embodiments, and such use of the terms should be interpreted as “serving as an example, illustration, or description,” and should not necessarily be interpreted as being preferable or advantageous to other embodiments.

[0035] When the terms "approximately" or "nearly" are used with numbers, they are understood, as those skilled in the art would understand, to mean a specific number, or alternatively, a range close to a specific number.

[0036] If the specification states that a component or feature “may include,” “may,” “may,” “should,” “would,” “preferably,” “possibly,” “typically,” “optionally,” “for example,” “often,” or “may” (or other such wording), then it is not required to include or have that particular component or feature. Such components or features may be optionally included in or excluded from some embodiments.

[0037] The following description is illustrated by reference to the accompanying drawings, which form part of this specification, illustrating specific embodiments that can be implemented. These embodiments are described in sufficient detail so that those skilled in the art can implement the disclosure, and it should be understood that other embodiments can be utilized and structural, logical, and electrical modifications can be made without departing from the scope of the disclosure. Accordingly, the following description of exemplary embodiments should not be construed as restrictive.

[0038] Figures 2A and 2B show various views of the thermo-optic phase shifter 200 according to a first embodiment of the present disclosure. Figure 2A shows a top view of the thermo-optic phase shifter 200, and Figure 2B shows a cross-sectional view.

[0039] The thermo-optic phase shifter 200 comprises a substrate 202, a buried oxide (BOX) layer 204, and a waveguide 206. Furthermore, the thermo-optic phase shifter 200 includes a heater 208 and a cladding layer 210. The substrate 202 has several trenches, such as trenches 212, 214, 216, 218, and 220, as shown in Figure 2B.

[0040] In this regard, the trenches 212, 214, 216, 218, and 220 are contained within the substrate layer and include holes or spaces between the substrate pillar structures 226 that are in contact with the BOX layer 204. The trenches 212, 214, 216, 218, and 220 are formed so that the upper and upper layers of the substrate layer are suspended via the pillar structures 226. Such a structural configuration may be referred to as a suspension structure, as used herein. The suspension structure involves suspending the optical waveguide 206, BOX 204, and cladding layer 210 by partial etching of the silicon (Si) substrate.

[0041] The oxide layer 205 separates the heater 208 and the optical waveguide 206 to reduce metal absorption. In one embodiment, the oxide layer 205 can act as a cladding layer for a thermal phase optical shifter without the heater 208. Furthermore, the oxide layer 205 acts to separate light.

[0042] In one example, the substrate 202 is made of silicon. In another example, the substrate 202 is formed from a glass material containing quartz or silica. As shown in Figure 2B, the substrate 202 includes several trenches 212, 214, 216, 218, and 220. Figure 2B shows a substrate 202 having five trenches 212, 214, 216, 218, and 220, but in some embodiments, there may be more than five trenches in the substrate 202. In Figure 2B, there are five trenches, but it will be understood that the number of trenches may be less than five or more than two. The length (L) of each trench may be less than 80 μm. The number of trenches may depend on the total length of each structure. Trenches can be formed by etching.

[0043] Each of the trenches 212, 214, 216, 218, and 220 can have the same length L1 and period P1, and each trench 212, 214, 216, 218, and 220 is positioned equidistant from adjacent trenches in the substrate 202. In one example, the length L1 and period P1 are arbitrary values ​​based on the structure of the trench. In one example, the trenches are obtained by partially etching the silicon substrate below the optical waveguide by an isotropic etching process. The optical waveguide is suspended in the air by small bridges to maintain its structure and prevent collapse.

[0044] In one example, the substrate 202 is positioned such that it extends outward along the transverse axis of the thermo-optic phase shifter 200, for example, on both sides of the waveguide 206. The substrate 202, waveguide 206, and heater 208 are aligned so that the trenches 212, 214, 216, and 218 are not covered by the waveguide 206 and heater 208 formed on the substrate 202. In one example, the trenches 212, 214, 216, 218, and 220 isolate heat dissipation. Since the heated optical waveguide is suspended in the air, there is no connection to the silicon substrate. Therefore, the trenches isolate heat dissipation to the silicon substrate. In comparison, Figures 1A and 1B show a structure 112 having trenches 124 on the sides of the waveguide, thereby allowing the air within the structure 112 to prevent heat dissipation to the silicon substrate.

[0045] In one embodiment, as shown in Figure 2A, each trench includes two holes or spaces on each side of the waveguide 206. For example, trench 212 includes two holes 212a and 212b. The depth of each of the two holes from the top of the cladding layer 210 to the substrate 202 can be 120 micrometers (μm). The holes themselves form the trench.

[0046] In one embodiment, the BOX layer 204 can be composed of silica or silicon dioxide (SiO2). The BOX layer 204 is sandwiched between a thicker silicon substrate, such as substrate 202, and an upper silicon layer 203, thereby allowing the BOX layer 204 to function as an insulating layer. The BOX layer 204 has two opposing surfaces, an upper and a lower surface. In one embodiment, the upper silicon layer 203 is in contact with the upper surface of the BOX layer 204, and the substrate 202 is in contact with the lower surface of the BOX layer 204 via substrate pillars 226. During the operation of the thermo-optic phase shifter 200, the BOX layer 204 prevents light leakage to the substrate 202. The BOX layer 204 is thicker than, for example, 2 micrometers to prevent optical coupling to the substrate. This offers the advantage of reducing optical loss.

[0047] Waveguide 206 is formed on top of BOX layer 204 and is made of a high thermo-optical coefficient material with a linear refractive index, such as silicon or silicon nitride. The refractive index changes in response to temperature changes, with increasing temperature increasing the refractive index and decreasing temperature decreasing the refractive index. In one example, the material of waveguide 206 is selected such that a change in the refractive index of waveguide 206 causes a change in the phase of light rays passing through waveguide 206. Waveguide 206 may be used to couple optical signals, such as input signals and corresponding output signals, in and out of thermo-optical phase shifter 200.

[0048] The heater 208 is, in one example, made of a metal such as doped silicon or titanium nitride (TiN). The heater 208 is positioned adjacent to the waveguide 206 and extends along the length of the waveguide 206. In one example, the heater 208 is a single heating element extending along the length of the waveguide 206, or multiple heating elements dispersed around the waveguide 206. The purpose of positioning the heater 208 is to provide direct and efficient heating to the waveguide 206 and to rapidly increase the refractive index of the waveguide 206.

[0049] Heater 208 generates heat based on the voltage applied by the power supply. The power supply is electrically connected to heater 208 via a pair of electrodes. For example, when heating heater 208, the power supply applies a voltage to heater 208, causing the heater to generate heat. The amount of heat generated depends on the change in the voltage applied to heater 208. In one example, heater 208 supplies a large amount of heat to waveguide 206, causing a rapid increase in the temperature of waveguide 206. For example, if heater 208 is made of titanium nitride (TiN), titanium (Ti), or other material, when electricity is applied, heater 208 supplies heat. When waveguide 206 is heated, the refractive index of waveguide 206 changes based on the temperature response of waveguide 206. The change in refractive index causes a change in the phase and intensity of the signal transmitted as an output signal through waveguide 206.

[0050] In one embodiment of the present disclosure, the cladding layer 210 is composed of an insulating material such as silicon dioxide (SiO2). The cladding layer 210 is positioned above the heater 208. The cladding layer 210 protects the thermo-optic phase shifter 200 and separates light between the heater 208 and the waveguide 206.

[0051] The thermo-optic phase shifter 200 has a rectangular shape, as shown in Figures 2A and 2B. The thermo-optic phase shifter 200 is configured to receive an input signal at one end 222 and transmit an output signal at the other end 224. In one example, the input and output signals are light waves or optical waves received by and propagating through the thermo-optic phase shifter 200. In one example, if no phase shift is performed by the thermo-optic phase shifter 200, the input and output signals are collinear with each other along the principal axis of the thermo-optic phase shifter 200. In other words, if the input signal enters the thermo-optic phase shifter 200 from end 222 and the output signal is transmitted from the other end 224, the input and output signals are substantially along the same line. In one example, the output signal has the same amplitude and frequency as the input signal. The thermo-optical phase shifter 200 has suspension regions arranged in partially different ratios to balance power consumption and speed. In Figure 2B, there is no duty cycle, and the only parameter is the length of the suspension section. As the length increases, the speed decreases and the efficiency increases. As the length decreases, the speed increases and the efficiency decreases.

[0052] During operation in which a phase shift is introduced by the thermo-optic phase shifter 200, the power supply applies a voltage to the heater 208, which heats the waveguide 206 as described above. Heating the waveguide 206 changes the refractive index, thereby changing the phase of the input signal. As the input signal propagates through the thermo-optic phase shifter 200, the trenches 212, 214, 216, 218, and 220 in the substrate 202 provide different duty cycles, thereby improving the efficiency and speed of intensity modulation. The output signal is transmitted from the thermo-optic phase shifter 200 with a phase difference relative to the input signal. The magnitude of the phase difference is based on the amount of voltage applied to the thermo-optic phase shifter 200. The higher the voltage applied to the thermo-optic phase shifter 200, the higher the temperature of the heater 208 and the greater the phase shift of the output signal. The trenches 212, 214, 216, 218, and 220 allow for adjustment of the efficiency and speed of intensity modulation by the thermo-optic phase shifter 200.

[0053] Figures 3A and 3B show various views of the thermo-optic phase shifter 300 according to a second embodiment of the present disclosure. Figure 3A is a top view of the thermo-optic phase shifter 300, and Figure 3B is a cross-sectional view of the thermo-optic phase shifter 300.

[0054] The thermo-optic phase shifter 300 includes a substrate 302, a buried oxide (BOX) layer 304, an oxide layer 305, and a waveguide 306. The thermo-optic phase shifter 300 also includes a heater 308 and a cladding layer 310. The substrate 302 has a single trench 312, as shown in Figure 3B. The trench 312 is located in a portion of the substrate 302, for example, within the central region of the substrate 302.

[0055] The substrate 302 is made of silicon or glass material containing quartz. In one embodiment, the trench 312 has a predetermined length L2 and has two holes on each side of the waveguide 306. The depth of each of the two holes from the top of the cladding layer 310 to the substrate 302 is 120 μm. In one example, the substrate 302 defining the trench 312 extends outward on both sides of the waveguide 306 along the transverse axis of the thermo-optic phase shifter 300. The substrate 302, waveguide 306, and heater 308 are aligned so that the trench 312 is not covered by the waveguide 306 and heater 308.

[0056] In one embodiment, as shown in Figure 3A, the trench 312 includes two holes on each side of the waveguide 306. For example, the trench 312 includes two holes 312a and 312b. The depth of each of the two holes from the top of the cladding layer 310 to the substrate 302 may be 120 micrometers (μm).

[0057] In one embodiment, the BOX layer 304 is made of silica. The waveguide 306 is formed on the BOX layer 304 and is made of a high thermo-optical coefficient material having a linear refractive index, such as silicon or silicon nitride. The refractive index of the waveguide 306 changes with temperature. The heater 308 is positioned adjacent to the waveguide 306 and extends along the length of the waveguide 306. In one example, the heater 308 has a plurality of heating elements dispersed around the waveguide 306.

[0058] As illustrated with reference to Figures 2A and 2B, the heater 308 is similarly connected to a power supply via a pair of electrodes, and when a voltage is applied through the pair of electrodes, fluctuations in the voltage cause fluctuations in the temperature of the heater 308. The heater 308 is, in one example, made of a metal such as doped silicon or titanium nitride (TiN).

[0059] In an exemplary embodiment, the cladding layer 310 is composed of an insulating material such as silicon dioxide (SiO2). The cladding layer 310 protects the thermo-optic phase shifter 300 and separates light between the heater 308 and the waveguide 306.

[0060] During operation, the thermo-optic phase shifter 300 receives the input signal at one end 314 of the thermo-optic phase shifter 300. The phase shift performed by the thermo-optic phase shifter 300 is based on heating by heater 308, as well as heating by heater 208, as described above with respect to the operation of the thermo-optic phase shifter 200. As the input signal propagates through the thermo-optic phase shifter 300, the trench 312 provides different duty cycles, improving the efficiency and speed of intensity modulation. The output signal is then transmitted from the other end 316 of the thermo-optic phase shifter 300. The output signal has a phase difference with respect to the input signal.

[0061] In one example, the magnitude of the phase difference is based on the voltage applied to the thermo-optic phase shifter 300. The trench 312 provides different duty cycles, which in turn provide the corresponding efficiencies and speeds in phase modulation, thus allowing for adjustment of efficiency and speed.

[0062] The adjustment of speed and efficiency is shown in Graph 400 of Figure 4. Figure 4 shows the test results for different duty cycles and suspension length or overall heater length. Graph 400 shows power efficiency plotted on the y-axis against time and heater length plotted on the x-axis. Lines 402 and 404 show the experimental results of the thermo-optic phase shifter 200 in Figures 2A and 2B. Graph 400 shows the rise limit time constant or measurement results of speed and power efficiency for different ratios of suspension heater length to overall heater length. In Figure 4, when the duty cycle is 100%, the structure has the entire suspension heater with low power consumption and low speed as in Figure 1B, and when the duty cycle is 0%, the structure has no suspension heater with high power consumption and high speed as in Figure 1A. The experimental results are equivalent for both embodiments in Figures 2A-B and 3A-B.

[0063] In one example, an ultra-low power 2x2 thermo-optic waveguide-based switch is manufactured using a standard complementary metal-oxide-semiconductor (CMOS) process. The phase arms are suspended by removing adjacent SiO2 and the underlying 120 micrometers of Si, while leaving a small SiO2 beam to support the suspended phase arms for structural strength. A significant power consumption reduction of over 98% is achieved compared to a switch without an insulating layer. This power consumption reduction is achieved by preventing heat leakage from the phase arms due to the presence of an air insulating layer. The thermo-optic phase shifter according to the present invention exhibits an extinction ratio of over 23 dB at 1550 nm for the TE mode with an ultra-low power consumption of 0.49 milliwatts (mW), and a response time of 266 microseconds, including a rise time of 144 microseconds and a fall time of 122 microseconds.

[0064] The operation of the thermo-optical phase shifters 200 and 300 will be explained in relation to Figure 5.

[0065] Referring to Figure 5, a method flowchart 500 is described, relating to Figures 2A and 2B, and Figures 3A and 3B, illustrating the adjustment of the speed and efficiency of intensity modulation by thermo-optic phase shifters such as thermo-optic phase shifters 200 and 300.

[0066] The process first moves to block 502, where an input signal is received. The input signal is an optical signal, an optical wave, or an incident ray. In one example, the input signal is received by a thermo-optic phase shifter, such as thermo-optic phase shifters 200 and 300. The thermo-optic phase shifter includes a substrate defining at least one trench, a box layer formed on the substrate, a waveguide positioned on the box layer, and a heater. The substrate extends partially outward on both sides of the waveguide.

[0067] The heater is positioned adjacent to the waveguide to directly heat the waveguide. In one example, the heater is connected to a power supply via a pair of electrodes or wires. The power supply is used to generate heat by applying a voltage to the heater. In block 504, the voltage applied to the heater of the thermo-optic phase shifter is adjusted. The voltage is adjusted to control the amount of heat generated by the heater. The amount of heat generated by the heater changes the refractive index of the waveguide. The waveguide modulates the phase of the input signal based on the change in the refractive index of the waveguide and transmits the output signal.

[0068] Subsequently, in block 506, the output signal is transmitted from the thermo-optic phase shifter. In one example, the phase of the output signal differs from the phase of the input signal, and the phase difference is based on the change in applied voltage. For example, a higher voltage increases the phase difference between the input and output signals, and a decrease in applied voltage decreases the phase difference. A substrate having at least one trench creates a difference in the duty cycle, allowing for a balance between the speed and power efficiency of the thermo-optic phase shifter.

[0069] While several embodiments are provided in this disclosure, it should be understood that the disclosed systems and methods can be embodied in many other specific forms without departing from the spirit or scope of this disclosure. These embodiments should be considered illustrative and not limiting, and their intent is not limited to the details described herein. For example, various elements or components may be combined or integrated into another system, or certain features may be omitted or not implemented.

[0070] Furthermore, technologies, systems, subsystems, and methods described and explained individually or separately in various embodiments may be combined or integrated with other systems, modules, technologies, or methods without departing from the scope of this disclosure. Other items shown or described as directly coupled or communicating with one another may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrical, mechanical, or otherwise. Other examples of modifications, substitutions, and alterations are readily apparent to those skilled in the art and can be made without departing from the spirit and scope disclosed herein.

[0071] Various embodiments relating to the principles disclosed herein have been shown and described above, but modifications thereof can be made by those skilled in the art without departing from the spirit and teachings of this specification. The embodiments described herein are merely representative and are not intended to limit. Many variations, combinations, and modifications are possible and within the scope of this disclosure. Alternative embodiments resulting from combining, integrating, and / or omitting features of the embodiments are also within the scope of this disclosure. Thus, the scope of protection is not limited by the above description and is defined by the following claims, the scope of which includes all equivalents of the subject matter of the claims. Each claim is incorporated herein as a further disclosure, and the claims are embodiments of the invention. Furthermore, any of the above advantages and features may relate to a particular embodiment but are not limited to achieving any or all of the above advantages or having any or all of the above features in any process and structure to which such published claims apply.

[0072] While various systems and methods have been described herein, various embodiments of these systems and methods may include, but are not limited to, the claims provided herein.

Claims

1. A substrate defining at least one trench, A waveguide configured to guide the input signal, The upper silicon layer and A BOX layer formed between the substrate and the upper silicon layer, which is an insulating layer that is in contact with the substrate and isolated from the waveguide by the upper silicon layer, A thermo-optical phase shifter comprising: a heater, wherein the waveguide is disposed between the heater and the BOX layer, and the heater is configured to heat the waveguide; The heater comprises a cladding layer arranged along its length and configured to cover and protect the thermo-optical phase shifter, A thermo-optical phase shifter comprising at least one trench containing two holes extending from the substrate to the top of the cladding layer, each located on a side of the waveguide.

2. The thermo-optical phase shifter according to claim 1, wherein at least one of the trenches has a depth of 120 micrometers (μm).

3. The thermo-optical phase shifter according to claim 1, wherein the substrate extends along the transverse axis of the waveguide, and at least one of the trenches is partially defined by the substrate and the BOX layer.

4. The thermo-optical phase shifter according to claim 1, further comprising a cladding layer composed of silicon dioxide (SiO2).

5. The thermo-optical phase shifter according to claim 1, further comprising an oxide layer configured to separate light between the heater and the waveguide.

6. The thermo-optical phase shifter according to claim 1, wherein each of the at least one trench has a different length.

7. The thermo-optical phase shifter according to claim 1, characterized in that the substrate is made of silicon or includes a glass material containing quartz or silica.

8. The thermo-optical phase shifter according to claim 1, characterized in that at least one of the trenches consists of five trenches.

9. The thermo-optical phase shifter according to claim 1, characterized in that at least one of the trenches consists of one trench.

10. A method for adjusting the speed and efficiency of intensity modulation, Receiving an input signal by a thermo-optical phase shifter as described in claim 1, wherein the input signal is an optical signal, and receiving an input signal, Adjusting the voltage applied to the heater of the thermo-optical phase shifter, A method comprising transmitting an output signal from the thermo-optic phase shifter, wherein the output signal has a different phase from the input signal, and the phase difference is based on a change in the applied voltage.

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