CN217484626U

CN217484626U - Phase modulator

Info

Publication number: CN217484626U
Application number: CN202220657066.8U
Authority: CN
Inventors: 余朝晃; 隋军; 梁炳寅
Original assignee: Zhongke Xintong Microelectronics Technology Beijing Co ltd
Current assignee: Zhongke Xintong Microelectronics Technology Beijing Co ltd
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2022-09-23
Anticipated expiration: 2032-03-23

Abstract

The utility model relates to the technical field of optical fiber communication, and provides a phase modulator, which comprises a substrate layer, a buried metal layer, a lower cladding, a waveguide layer, an upper cladding and an upper electrode layer, wherein the buried metal layer, the lower cladding, the waveguide layer, the upper cladding and the upper electrode layer are arranged on the substrate layer and are sequentially formed from bottom to top; the lower cladding, the waveguide layer and the upper cladding form an optical waveguide for guiding the transmission of optical signals to be modulated; the buried metal layer and the upper electrode layer form a microstrip line for transmitting a microwave signal for modulating the optical signal to be modulated; the optical waveguide and the microstrip line are arranged in an overlapping mode. The utility model provides a phase modulator through improving modulation efficiency, obtains lower half-wave voltage, can shorten device length, realizes the speed matching of broadband modulation signal and light carrier easily to the bandwidth has been improved, the consumption has been reduced.

Description

Phase modulator

Technical Field

The utility model relates to an optical fiber communication technical field especially relates to a phase modulator.

Background

The phase modulator is used as a photoelectric device and widely applied to the application fields of digital light and analog optical communication, atomic sensing and the like. In the field of digital optical communications, a Phase modulator may modulate a DPSK (Differential Phase Shift Keying) digital signal into an optical domain for long-distance transmission. In the field of analog optical communication, a phase modulator can be used for radio over fiber signal transmission of external modulation-coherent detection and can also be used for radar deskew reception. In the field of atom sensing, phase modulators are commonly used to generate optical sidebands with fixed phase differences for interaction with atoms. Compared with a Mach-Zehnder intensity modulator, the phase modulator does not need bias point control, so that the system based on the phase modulator is simpler in structure and more suitable for severe environments. In addition, the phase modulator does not change the amplitude of an optical field, is weaker due to the nonlinear action of the optical fiber, does not comprise a beam splitting structure and a beam combining structure, and does not have the inherent 3dB optical loss problem.

With the development of 5G (5th generation mobile communication technology) communication technology, mobile terminals are gradually popularized, access devices in networks are more and more diversified, user multimedia service requirements are increased rapidly, and the problem of network communication bottleneck is aggravated. Therefore, how to increase the bandwidth of the phase modulator and reduce the energy consumption of the phase modulator to meet the increasing data service requirements becomes an urgent technical problem to be solved in the industry.

SUMMERY OF THE UTILITY MODEL

The utility model provides a phase modulator for the bandwidth of solving phase modulator among the prior art is lower, the higher technical problem of energy consumption.

The utility model provides a phase modulator, which comprises a substrate layer, a buried metal layer, a lower cladding, a waveguide layer, an upper cladding and an upper electrode layer, wherein the buried metal layer, the lower cladding, the waveguide layer, the upper cladding and the upper electrode layer are arranged on the substrate layer and sequentially formed from bottom to top;

the lower cladding, the waveguide layer and the upper cladding form an optical waveguide for guiding the transmission of optical signals to be modulated; the buried metal layer and the upper electrode layer form a microstrip line for transmitting a microwave signal for modulating the optical signal to be modulated;

the optical waveguide and the microstrip line are arranged in an overlapping mode.

According to the utility model provides a phase modulator, the material of waveguide layer is the thin film lithium niobate is cut to Z.

According to the utility model provides a phase modulator, the structure of waveguide layer is the ridge shape.

According to the utility model provides a phase modulator, waveguide layer is based on electron beam exposure and argon ion etching preparation.

According to the phase modulator provided by the utility model, the microstrip line comprises an input section, a working section and an output section;

the input section and the output section are respectively vertical to the working section; the working section is arranged in an overlapping manner with the optical waveguide;

the connection part of the working section and the input section and the connection part of the working section and the output section adopt 45-degree beveling structures.

According to the utility model provides a phase modulator, the material of substrate layer is quartz material.

According to the utility model provides a phase modulator, the material of burying the metal level is gold, the thickness of burying the metal level is greater than 1 micron.

According to the utility model provides a phase modulator, the material of lower covering is silica.

According to the utility model provides a phase modulator, the material of upper cladding is silica.

According to the utility model provides a phase modulator, the material of going up electrode layer is gold.

The utility model provides a phase modulator, including the substrate layer, and set up on the substrate layer, the buried metal layer that forms in proper order from bottom to top, the under cladding, the waveguide layer, upper cladding and upper electrode layer, the under cladding, waveguide layer and upper cladding constitute the optical waveguide, buried metal layer and upper electrode layer constitute the microstrip line, the optical waveguide overlaps with the microstrip line and sets up, make the distribution height who treats optical mode field of modulated light signal and microwave signal's electric field overlap, the modulation efficiency has been improved, half-wave voltage in the phase modulator has been reduced, be used for shortening phase modulator's length with half-wave voltage's optimization surplus, realize easily that broadband modulation signal and light carrier's speed match, thereby phase modulator's bandwidth has been improved, phase modulator's consumption has been reduced.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a phase modulator provided by the present invention;

fig. 2 is a top view of the phase modulator provided by the present invention.

Reference numerals:

110: a substrate layer; 120: burying a metal layer; 130: a lower cladding; 140: a waveguide layer; 150: an upper cladding layer; 160: an upper electrode layer; 210: a light input end; 220: a light output end; 230: a modulation signal input terminal; 240: and a modulation signal output terminal.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

In the description of the embodiments of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings, which are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected" and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the embodiments of the present invention can be understood in specific cases by those skilled in the art.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an embodiment of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

The electrodes of the phase modulator are typically traveling wave electrodes whose electrical signal speed matches the optical wave transmission speed. By reducing the half-wave voltage of the phase modulator, the power consumption of the device can be reduced. The half-wave voltage-length product of the phase modulator is usually a fixed value, and the half-wave voltage of the device can be reduced by increasing the length of the device, but the half-wave voltage of the device is difficult to match with the long-distance transmission of the optical waveguide due to the fact that the high-frequency electric signal is difficult to match with the optical waveguide, and the bandwidth of the device is reduced.

Fig. 1 is a schematic structural diagram of a phase modulator provided by the present invention, as shown in fig. 1, the phase modulator includes a substrate layer 110, and a buried metal layer 120, a lower cladding layer 130, a waveguide layer 140, an upper cladding layer 150, and an upper electrode layer 160, which are disposed on the substrate layer 110 and sequentially formed from bottom to top;

the lower cladding layer 130, the waveguide layer 140 and the upper cladding layer 150 constitute an optical waveguide for guiding the transmission of the optical signal to be modulated; the buried metal layer 120 and the upper electrode layer 160 constitute a microstrip line for transmitting a microwave signal for modulating an optical signal to be modulated; the optical waveguide and the microstrip line are overlapped.

Specifically, the embodiment of the utility model provides a phase modulator is for the electro-optic modulator that can make the phase place of light change according to certain law, has utilized the electro-optic effect, and under the effect of additional electric field promptly, the change and the direct proportion of applied electric field intensity of electro-optic material refracting index.

Structurally, the phase modulator provided by the embodiments of the present invention includes, from bottom to top, a substrate layer 110, a buried metal layer 120, a lower cladding layer 130, a waveguide layer 140, an upper cladding layer 150, and an upper electrode layer 160. From a chip fabrication perspective, buried metal layer 120, lower cladding layer 130, waveguide layer 140, upper cladding layer 150, and upper electrode layer 160 can again be considered epitaxial layers grown on substrate layer 110. Here, the growth order of the epitaxial layers on the chip is from bottom to top.

From substrate layer 110 up, buried metal layer 120 is grown on substrate layer 110, lower cladding layer 130 is grown on buried metal layer 120, waveguide layer 140 is grown on lower cladding layer 130, upper cladding layer 150 is grown on waveguide layer 140, and upper electrode layer 160 is grown on upper cladding layer 150.

The substrate layer 110 bears the stress of the chip to ensure the transfer processing of the chip. Substrate layer 110 is a clean single crystal sheet having a particular crystal plane and appropriate electrical, optical, and mechanical characteristics for growing epitaxial layers.

An optical waveguide (optical waveguide) is a medium device for guiding light waves to propagate therein, and is also called a medium optical waveguide. The optical waveguide may be a guide structure made of an optically transparent medium for transmitting electromagnetic waves at an optical frequency. The transmission principle of the optical waveguide is different from that of a metal closed waveguide, and the total reflection phenomenon of electromagnetic waves causes the optical waveguide to be limited in the waveguide and a limited region around the waveguide to be transmitted on a medium interface with different refractive indexes.

The lower cladding layer 130, the waveguide layer 140 and the upper cladding layer 150 constitute an optical waveguide for guiding the transmission of the optical signal to be modulated. The lower cladding layer 130 and the upper cladding layer 150 serve to longitudinally confine the optical field in the phase modulator waveguide. After entering the optical waveguide, the optical signal to be modulated can only propagate in the waveguide layer 140 due to the confinement of the upper cladding layer 150 and the lower cladding layer 130.

The material of the lower cladding 130 and the upper cladding 150 may be the same. For example, Silica (SiO) may be used for both the lower cladding 130 and the upper cladding 150 ₂ ). The materials of the lower cladding layer 130 and the upper cladding layer 150 have different refractive indices from the material in the waveguide layer 140. For example, the lower cladding 130 has a refractive index n ₀ The refractive index of the waveguide layer 140 is n ₁ The upper cladding layer 150 has a refractive index n ₂ ，n ₀ And n ₂ Are all less than n ₁ . When an optical signal to be modulated enters the optical waveguide, the optical signal is mainly concentrated in the optical waveguide for transmission.

Microstrip lines are microwave transmission lines made of a single conductor strip provided on a dielectric substrate. The buried metal layer 120 and the upper electrode layer 160 constitute a microstrip line for transmitting a microwave signal for modulating an optical signal to be modulated.

The buried metal layer 120 and the upper electrode layer 160 constitute a microstrip line traveling wave electrode structure. Among them, the buried metal layer 120 may serve as a lower electrode in the traveling wave electrode to which the microwave modulation signal is applied in the phase modulator, and the upper electrode layer 160 may serve as an upper electrode in the traveling wave electrode to which the microwave modulation signal is applied in the phase modulator. In the embodiment of the present invention, the buried metal layer 120 and the upper electrode layer 160 are disposed in parallel.

The embodiment of the utility model provides an among the phase modulator, the optical waveguide overlaps with the microstrip line and sets up. The buried metal layer 120 is disposed below the lower cladding layer 130 and the upper electrode layer 160 is disposed above the upper cladding layer 150, as viewed from the chip structure, so that the optical waveguide is located between the two traveling wave electrodes of the microstrip line. The structure enables the distribution of the optical mode field of the optical signal to be modulated and the electric field of the microwave signal to be highly overlapped, and can effectively improve the modulation efficiency of the phase modulator.

In the prior art, a coplanar waveguide electrode modulator (CPW) is generally adopted, and the type of CPW adopts a planar structure, has the characteristics of small volume and light weight, but has the problems of low modulation efficiency and high power consumption. The embodiment of the utility model provides a phase modulator treats the overlapping degree of modulation light signal's optical mode field and microwave signal's electric field through the increase, has improved modulation efficiency to obtain lower half-wave voltage, reduced phase modulator's consumption. Under the condition that the half-wave voltage-length product of the phase modulator is a fixed value, the optimized allowance of the half-wave voltage can be used for shortening the length of the phase modulator, the speed matching of a broadband modulation signal and an optical carrier is easy to realize, and therefore the bandwidth of the phase modulator is improved.

The embodiment of the utility model provides a phase modulator, including the substrate layer, and set up on the substrate layer, the buried metal level that upwards forms in proper order from bottom to top, the under cladding, the waveguide layer, under cladding and last electrode layer, the under cladding, waveguide layer and upper cladding constitute the optical waveguide, buried metal level and last electrode layer constitute the microstrip line, the optical waveguide overlaps the setting with the microstrip line, make the distribution height who treats the optical mode field of modulated light signal and the electric field of microwave signal overlap, the modulation efficiency is improved, half-wave voltage in the phase modulator has been reduced, be used for shortening phase modulator's length with half-wave voltage's optimization surplus, realize broadband modulated signal and the speed matching of light carrier easily, thereby phase modulator's bandwidth has been improved, the power consumption of phase modulator has been reduced.

Based on the above embodiment, the waveguide layer is made of Z-cut thin-film lithium niobate.

Specifically, the lithium niobate is an inorganic substance, is a negative crystal and a ferroelectric crystal, and has multiple properties of piezoelectricity, ferroelectricity, photoelectricity, nonlinear optics, thermoelectricity and the like and a photorefractive effect. The lithium niobate is used as an electro-optical material to play an optical modulation role in optical communication.

The optical waveguide prepared from the thin film lithium niobate material has larger refractive index difference. For example, in a lithium niobate thin film substrate having an upper cladding layer of air and a lower cladding layer of silica, the difference in refractive index between the substrate and the upper cladding layer material is 1.1 to 1.2, and the difference in refractive index between the substrate and the lower cladding layer material is 0.6 to 0.8. In contrast, the refractive index difference of the optical waveguides prepared in the lithium niobate bulk material is generally on the level of 0.01, much smaller than that of thin film lithium niobate optical waveguides. Therefore, the thin film lithium niobate optical waveguide has strong constraint on light waves, and can manufacture optical devices with smaller size and smaller bending radius.

The Z cut (Z cut) thin film lithium niobate is light transmitted along the Z direction, the effective nonlinear coefficient in the direction is the largest, the largest electro-optic coefficient in the thin film lithium niobate material can be utilized, the optical field can be more effectively modulated, and the half-wave voltage is reduced.

According to any of the above embodiments, the waveguide layer has a ridge structure.

Specifically, the waveguide layer is made of a crystal material with an electro-optic effect, a ridge waveguide structure can be adopted, strong transverse limitation is generated on an optical field, the waveguide width needs to be small enough, and the waveguide transverse mode is a single mode within the working wavelength of the device.

A ridge waveguide can be seen as a rectangular waveguide folded with an electromagnetic field pattern similar to that of the rectangular waveguide except that the field distribution is disturbed near the ridge due to edge effects.

Compared with a rectangular waveguide with the same size, the cut-off frequency of the main mode is low; the single-mode working frequency band is wide and can reach a plurality of octaves; the equivalent impedance is low, so the coaxial line and the microstrip line with low impedance are easily matched.

The waveguide layer can adopt a ridge structure and is formed on the upper surface of the waveguide layer, and the raised structure can be obtained on the upper surface of the Z-cut thin film lithium niobate by dry etching, wet etching, optical precision cutting or other technological methods. The ridge structure forms local effective refractive index increase in the Z-cut thin film lithium niobate, and can realize local constraint on optical signals incident into the waveguide layer.

In any of the above embodiments, the waveguide layer is prepared based on electron beam exposure and argon ion etching.

In particular, the waveguide layer may be prepared by electron beam exposure and reactive ion etching processes.

HSQ (hydrogen siloxane, H-SiQ) is an inorganic material having good plasma resistance and high resolution. The electron beam exposure adopts HSQ glue, the solidified HSQ glue is used as a mask, and argon (Ar) is adopted for reactive ion etching to form a shallow etching waveguide. The mask manufactured by electron beam exposure has good roughness, and the light transmission loss of the device is reduced.

Based on any of the above embodiments, the microstrip line includes an input section, a working section, and an output section;

the input section and the output section are respectively vertical to the working section; the working section is overlapped with the optical waveguide;

the connection part of the working section and the input section and the connection part of the working section and the output section adopt a 45-degree beveling structure.

Specifically, fig. 2 is a top view of the phase modulator provided by the present invention, as shown in fig. 2, the phase modulator includes an optical input end 210, an optical output end 220, a modulation signal input end 230, and a modulation signal output end 240. In the figure, the solid line is an optical waveguide, and the strip-shaped dotted line is a microstrip line.

An optical carrier is coupled into the optical waveguide of the phase modulator from an optical input 210 via an optical fiber, exciting a TM fundamental mode. The microstrip line is U-shaped, and the modulation signal input end 230 and the modulation signal output end 240 are respectively perpendicular to the optical waveguide direction, which is convenient for packaging the phase modulator. And a 45-degree beveling structure is adopted at the turning position of the U-shaped electrode, so that the excitation of reflection and high-order transmission modes caused by the discontinuity of the optical waveguide is inhibited. The modulation signal output terminal 240 of the phase modulator is connected to the matching load for suppressing the reflection of the microwave modulation signal. The transmission speed of the optical field in the TM polarization mode in the optical waveguide matches the transmission speed of the microwave signal, and the phase of the optical wave is modulated by the electro-optic effect and then coupled to the optical fiber for output through the optical output 220.

The TM fundamental mode is a propagation mode in which the longitudinal component of a magnetic field is zero and the longitudinal component of an electric field is not zero in the waveguide.

Based on any of the above embodiments, the substrate layer is made of a quartz material.

In particular, the substrate layer may be made of quartz. The microwave modulation signal is loaded on the phase modulator through the traveling wave electrode, and the electromagnetic field distribution of the microwave modulation signal covers the substrate layer. The substrate layer dielectric may create dielectric losses to the microwave modulated signal. The quartz material has a low dielectric loss coefficient, and can reduce the loss of microwave modulation signals.

According to any of the embodiments above, the substrate layer has a thickness greater than 100 micrometers.

Specifically, the thickness of the substrate layer needs to be larger than 100 micrometers (um), so that the chip can bear the stress process in the process machining process. Meanwhile, the thickness of the substrate layer cannot be too thick, otherwise, the cut-off frequency of the surface mode of the microwave transmission electrode is within the signal modulation bandwidth, and leakage loss is caused.

Based on any of the above embodiments, the material of the buried metal layer is gold, and the thickness of the buried metal layer is greater than 1 μm.

Specifically, the buried metal layer serves as a lower electrode of the traveling wave electrode structure for loading the microwave modulation signal.

The existing electrode material is mainly platinum, but the platinum has relatively high resistance, and the dielectric loss of the phase modulator is increased to a certain extent. The buried metal layer can be made of gold (Au), so that the conductor loss of the microwave modulation signal is reduced.

Since gold has poor adsorption, the thickness of the buried metal layer can be increased, and excellent electrical conductivity can be achieved when the thickness of the buried metal layer is greater than 1 micrometer (um).

According to any of the above embodiments, the material of the lower cladding is silica.

Specifically, the lower cladding may employ Silica (SiO) ₂ ) Its dielectric constant is low, optical field limiting capacity is strong and electric parasitic parameter is small. Since the buried metal layer can produce metal absorption to the optical field, the lower cladding layer is too thin, which can result in increased optical insertion loss of the device. The lower cladding is too thick, which can reduce the electric field intensity generated by the microwave signal, and lead to the weakening of the electro-optic effect. Therefore, the selection of the lower cladding layer is optimized and balanced according to the material parameters.

According to any of the above embodiments, the upper cladding layer is made of silica.

Specifically, the upper cladding layer may be designed the same as the lower cladding layer, with the material selected to be silica.

Based on any of the above embodiments, the material of the upper electrode layer is gold.

Specifically, the upper electrode layer is an upper electrode of a traveling wave electrode for loading a microwave modulation signal in the phase modulator. Which forms a microstrip transmission line with the buried metal layer. Compared with the coplanar waveguide electrode (CPW) modulator widely adopted at present, the electric field intensity of the CPW modulator is higher, in addition, the microwave electric field distribution of the transmission line is highly overlapped with the optical mode field, the overlapping factor is high, and the modulation efficiency is better.

The upper electrode layer can adopt gold (Au), and the thickness of the upper electrode layer is ensured to be within the working bandwidth, and the conductor loss of the microwave modulation signal is minimum. The width of the microwave modulating electrode is ensured to ensure that the characteristic impedance of the microwave modulating electrode is 50 ohms (omega), and the microwave transmission speed is matched with the optical field speed. The upper electrode layer may also employ a titanium/gold (Ti/Au) material as an electrode.

Based on any of the above-mentioned embodiments, the utility model provides a high efficiency electro-optic phase modulator, its wafer structure is by lower supreme, includes the substrate layer in proper order to and set up on the substrate layer, bury metal level, lower cladding, waveguide layer, upper cladding and last electrode layer that form in proper order from bottom to top.

Wherein the substrate layer is made of semi-insulating silicon and has a thickness of more than 100 microns; the buried metal layer is made of gold (Au), and the thickness of the buried metal layer is larger than 1 micron; the lower cladding is made of silicon dioxide (SiO) ₂ ) (ii) a The waveguide layer is made of Z-cut thin-film lithium niobate and has a ridge structure; the upper cladding is made of silicon dioxide (SiO) ₂ ) (ii) a The material of the upper electrode layer is titanium/gold (Ti/Au).

The lower cladding portion, the waveguide layer portion, and the upper cladding portion constitute a waveguide, and the waveguide needs to have a single-mode transmission characteristic in an operating wavelength range of the phase modulator.

The upper electrode layer part and the buried metal layer part form a microwave signal modulation electrode, and the transmission speed of the microwave signal is matched with the waveguide speed.

Structurally, the optical waveguide and the microstrip line are arranged in an overlapping mode.

The embodiment of the utility model provides a high efficiency electro-optic phase modulator has following beneficial effect:

(1) the optical waveguide and the microstrip line are arranged in an overlapping mode, so that the overlapping factor of an optical field and a modulation electric field is increased, and compared with the existing coplanar waveguide electrode modulator, the coplanar waveguide electrode modulator has stronger electric field intensity and better optical field-electric field overlapping factor, and can improve the modulation efficiency;

(2) the microwave modulation signal is loaded by adopting the structure, and the waveguide layer of the Z-cut thin-film lithium niobate material is combined, so that the maximum electrooptical coefficient in the lithium niobate material can be utilized, and modulation with higher efficiency is realized;

(3) the structure can enhance the constraint effect of the waveguide on the optical field, reduce the distance of the traveling wave electrode, improve the electric field intensity of the modulation signal and further improve the modulation efficiency; by improving the modulation efficiency, lower half-wave voltage can be obtained, and the energy consumption of the phase modulator is reduced; the optimized margin of the half-wave voltage can be used for shortening the length of the device, the speed matching of the broadband modulation signal and the optical carrier is easier to realize, and the bandwidth of the phase modulator is improved.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment may be implemented by software plus a necessary general hardware platform, and may also be implemented by hardware. With this understanding in mind, the above technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes commands for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. A phase modulator is characterized by comprising a substrate layer, a buried metal layer, a lower cladding layer, a waveguide layer, an upper cladding layer and an upper electrode layer, wherein the buried metal layer, the lower cladding layer, the waveguide layer, the upper cladding layer and the upper electrode layer are arranged on the substrate layer and sequentially formed from bottom to top;

2. The phase modulator of claim 1, wherein the waveguide layer is Z-cut thin film lithium niobate.

3. The phase modulator of claim 2, wherein the waveguide layer structure is ridge-shaped.

4. The phase modulator of claim 3, wherein the waveguide layer is prepared based on e-beam exposure and argon ion etching.

5. The phase modulator of claim 1, wherein the microstrip line comprises an input section, an active section, and an output section;

6. The phase modulator according to any of claims 1 to 5, wherein the material of the substrate layer is a quartz material.

7. The phase modulator according to any of claims 1 to 5, wherein the buried metal layer is made of gold, and the thickness of the buried metal layer is greater than 1 μm.

8. The phase modulator according to any of claims 1 to 5, wherein the lower cladding layer is made of silica.

9. The phase modulator according to any of claims 1 to 5, wherein the upper cladding layer is made of silica.

10. The phase modulator according to any one of claims 1 to 5, wherein the upper electrode layer is made of gold.