阅读说明：本技术 一种片上集成铌酸锂多波复合处理器件及其制备方法 (On-chip integrated lithium niobate multi-wave composite processing device and preparation method thereof ) 是由 尹志军 倪荣萍 吴剑波 叶志霖 李胜雨 张虞 许志城 于 2021-08-20 设计创作，主要内容包括：本申请提供一种片上集成铌酸锂多波复合处理器件,所述多波复合处理器件能够实现多波产生、调制以及复用等功能,所述片上集成铌酸锂多波复合处理器件基于铌酸锂材料,将频率梳产生器、滤波器、调制器以及复用器等多个功能器件有机地集成于芯片上,所述复合处理器件应用于光模块能够大幅度缩小光模块的体积,提高工作效率及运行稳定性。(The application provides an integrated lithium niobate multiwave composite processing device on piece, multiwave composite processing device can realize functions such as multiwave production, modulation and multiplexing, integrated lithium niobate multiwave composite processing device on piece is based on the lithium niobate material, organically integrates a plurality of functional device such as frequency comb generator, wave filter, modulator and multiplexer on the chip, composite processing device is applied to the volume that the optical module can reduce the optical module by a wide margin, improves work efficiency and operating stability.)

1. An on-chip integrated lithium niobate multi-wave composite processing device, characterized in that, the on-chip integrated lithium niobate multi-wave composite processing device includes: the waveguide device comprises a waveguide substrate (1), and a micro-ring resonant cavity (2), a plurality of differential filters (3) and a plurality of electro-optical modulators (4) which are integrated on the waveguide substrate (1), wherein the micro-ring resonant cavity (2) is connected with the plurality of differential filters (3) in series, each differential filter (3) is respectively communicated with one electro-optical modulator (4), and the tail ends of the electro-optical modulators are combined into the same output port.

2. The on-chip integrated lithium niobate multiwave composite processing device according to claim 1,

the micro-ring resonant radius of the micro-ring resonant cavity (2) is 2-200 μm, preferably 60-100 μm; and/or

Q value greater than 10⁵Preferably greater than 10⁶。

3. The on-chip integrated lithium niobate multiwave multiplex processing device according to claim 1 or 2, wherein the differential filter (3) comprises a filter ring (31) and a bus waveguide (32).

4. The on-chip integrated lithium niobate multiwave multiplex processing device according to any one of claims 1 to 3, wherein modulation voltages of the respective differential filters (3) are different, whereby each differential filter (3) realizes a frequency-selective function.

5. The on-chip integrated lithium niobate multiwave multiplex processing device according to any one of claims 1 to 4, wherein the electro-optical modulator (4) is configured to load signals onto optical waves of different frequencies.

6. The on-chip integrated lithium niobate multiwave multiplex processing device according to any one of claims 1 to 5, wherein the electro-optical modulator (4) is a Mach-Zehnder electro-optical modulator.

7. The on-chip integrated lithium niobate multiwave multiplex processing device according to any one of claims 1 to 6, wherein the two branches of the mach-zehnder electro-optic modulator are two lithium niobate optical waveguides, and particularly, the two lithium niobate optical waveguides are formed by one 50: 50Y-junction.

8. The on-chip integrated lithium niobate multiwave multiplex processing device according to any one of claims 1 to 7, wherein all the electro-optical modulators (4) are arranged in a row.

9. The on-chip integrated lithium niobate multiwave multiplex processing device according to any one of claims 1 to 8, wherein two adjacent electro-optical modulators (4) share one ground electrode.

10. A method for producing the on-chip integrated lithium niobate multiwave composite processing device according to any one of claims 1 to 9, comprising:

step 1, preparing a waveguide structure on a polished single crystal lithium niobate thin film, wherein the single crystal lithium niobate thin film is provided with a silicon dioxide substrate;

step 2, preparing a micro-ring resonant cavity, a differential filter and an electro-optical modulator on the waveguide structure;

step 3, depositing metal layers used as electrodes at corresponding positions of the micro-ring resonant cavity, the differential filter and the electro-optical modulator;

step 4, plating SiO on the micro-ring resonant cavity, the differential filter, the electro-optical modulator and the metal layer₂And (3) a layer.

Technical Field

The application belongs to the field of semiconductor devices, and particularly relates to an on-chip integrated lithium niobate multi-wave composite processing device and a preparation method thereof.

Background

The concept of "integrated optics" was first introduced in 1969 by doctor belr laboratories s.e.miller, usa. Over the last half century of development, integrated optics have been widely researched and applied, and in particular, optical modules including integrated optics have become the physical basis for internet implementation. Specifically, the optical module generally includes three parts, i.e., an optoelectronic device, a functional circuit, and an optical interface, where the optoelectronic device includes a transmitting end and a receiving end, and generally, the optical module converts an electrical signal into an optical signal through the transmitting end, and the converted optical signal is transmitted through an optical fiber and then converted into an electrical signal by the receiving end of another optical module optoelectronic device, so as to implement conversion of the optical signal, where the transmitting end and the receiving end are integrated optical devices, respectively. As the number of multimedia services, the number of wireless accesses, the number of internet access devices, and the number of mobile users are continuously increasing, it is difficult for modern network broadband to meet the increasing network requirements. In order to achieve higher network bandwidth, higher data conversion speed and lower investment cost, the development of higher quality integrated optical devices is imperative.

The emitting end of the optical module on the market at present mainly utilizes a plurality of lasers to perform electro-absorption modulation and utilizes spatial light to be coupled to an optical fiber for wavelength division multiplexing, but the emitting end has the following problems: (1) the laser is the device with the highest failure rate in the optical module, so that the multiple lasers arranged in the transmitting end not only generate more total heat, but also are not beneficial to the stable operation of the optical module; (2) the modulation rate based on the electric absorption of the silicon material does not exceed 60GHz, and is only normally between 25GHz and 30GHz, so that the modulation rate can be limited by using the electric absorption modulation; in addition, silicon materials are used as transmission media, so that the optical loss is large; (3) a plurality of lasers and spatial light are coupled into the optical fiber for wavelength division multiplexing, so that a large amount of space is occupied, and the size of the optical module is increased.

Compared with foreign countries, most domestic research institutions stay in theoretical design and simulation of integrated optical devices and preparation of single optical devices, so that few commercial popularization can be really achieved, and huge demands of domestic markets cannot be met.

Disclosure of Invention

In order to solve at least one of the above problems, the present application provides an on-chip integrated lithium niobate multi-wave composite processing device, where the multi-wave composite processing device can realize functions of multi-wave generation, modulation, multiplexing, and the like, the on-chip integrated lithium niobate multi-wave composite processing device organically integrates a plurality of functional devices, such as a frequency comb generator, a filter, a modulator, and a multiplexer, on a chip based on a lithium niobate material, and the composite processing device is applied to an optical module, so that the volume of the optical module can be greatly reduced, and the working efficiency and the operating stability are improved.

An object of the present application is to provide an on-chip integrated lithium niobate multi-wave composite processing device, the on-chip integrated lithium niobate multi-wave composite processing device includes: the waveguide comprises a waveguide substrate 1, and a micro-ring resonant cavity 2, a plurality of differential filters 3 and a plurality of electro-optical modulators 4 which are integrated on the waveguide substrate 1, wherein the micro-ring resonant cavity 2 is connected with the plurality of differential filters 3 in series, each differential filter 3 is respectively communicated with one electro-optical modulator 4, and the tail ends of the electro-optical modulators are combined into the same output port.

In an achievable mode, the micro-ring resonant radius of the micro-ring resonant cavity 2 is 2 μm to 200 μm, preferably 60 μm to 100 μm; q value greater than 10⁵Preferably greater than 10⁶。

In an implementable manner, the differential filter 3 comprises a filter ring 31 and a bus waveguide 32.

In an implementable manner, the modulation voltages of the individual differential filters 3 are different, so that each differential filter 3 implements a frequency-selective function.

In an implementable manner, the electro-optic modulator 4 is used to load signals onto optical waves of different frequencies.

In one implementable form, the electro-optic modulator 4 is a mach-zehnder electro-optic modulator.

In one realizable approach, the two branches of the mach-zehnder electro-optic modulator are two lithium niobate optical waveguides, and in particular, the two lithium niobate optical waveguides are formed from one 50: 50Y-junction.

In one realisable form all the electro-optical modulators 4 are arranged in a row.

Further, two adjacent electro-optical modulators 4 share one ground electrode.

Another object of the present application is to provide a method for preparing the on-chip integrated lithium niobate multiwave composite processing device, the method comprising:

step 1, preparing a waveguide structure on a polished single crystal lithium niobate thin film, wherein the single crystal lithium niobate thin film is provided with a silicon dioxide substrate;

step 2, preparing a micro-ring resonant cavity, a differential filter and an electro-optical modulator on the waveguide structure;

step 3, depositing metal layers used as electrodes at corresponding positions of the micro-ring resonant cavity, the differential filter and the electro-optical modulator;

step 4, plating SiO on the micro-ring resonant cavity, the differential filter, the electro-optical modulator and the metal layer₂And (3) a layer.

And the packaged optical fiber can be used as a wavelength division multiplexing device.

In the present application, the single-crystal lithium niobate thin film having a silica substrate may be commercially available.

Compared with the prior art, the on-chip integrated lithium niobate multi-wave composite processing device can obtain a plurality of electro-optic modulation information with different wavelengths on the same chip, and can realize wavelength division multiplexing after the end of the chip is lumped, so that the size of the multi-wave composite processing device is greatly reduced, optical loss can be effectively reduced, and the on-chip integrated lithium niobate multi-wave composite processing device has higher working stability. The method for preparing the on-chip integrated lithium niobate multi-wave composite processing device has low production cost, is easy to operate and is convenient for large-scale production.

Drawings

Fig. 1 shows a schematic diagram of the on-chip integrated lithium niobate multiwave composite processing device;

FIG. 2a is a schematic diagram of a micro-ring resonator according to an embodiment;

FIG. 2b shows a schematic diagram of a micro-ring resonator;

FIG. 3a shows a schematic diagram of the structure of a differential filter of the present example;

FIG. 3b shows a schematic diagram of the differential filter;

FIG. 4a is a schematic diagram of an electro-optic modulator of the present example;

figure 4b shows a schematic diagram of the electro-optical modulator.

Description of the reference numerals

1-waveguide substrate, 2-micro-ring resonant cavity, 3-differential filter, 31-filter ring, 32-bus waveguide and 4-electro-optical modulator.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of methods consistent with certain aspects of the invention, as detailed in the appended claims.

The on-chip integrated lithium niobate multiwave composite processing device and the preparation method thereof provided by the present application are explained in detail by specific embodiments below.

First, a brief introduction is made to a usage scenario of the present solution.

The optical module is composed of an optoelectronic device, a functional circuit, an optical interface component and the like, generally, the optoelectronic device comprises a transmitting end and a receiving end, wherein the receiving end is used for converting a received optical signal into an electrical signal, and the transmitting end is used for converting the electrical signal into an optical signal and transmitting the optical signal to other modules. In a signal transmission process, a transmitting end of a first optical module converts an electrical signal into an optical signal, the optical signal obtained by conversion is transmitted to a second optical module along an optical fiber, a receiving end of the second optical module receives the optical signal and converts the optical signal into an electrical signal, and so on, the transmitting end of the second optical module converts the electrical signal into an optical signal and continues to transmit information to a subsequent optical module.

In the traditional scheme, each optical module comprises a plurality of devices such as a frequency comb generator, a filter, a modulator and a multiplexer, each device is arranged independently, and the laser, the frequency comb generator and the filter which are independent of each other are connected with an electro-optical modulator through an interface and an optical fiber, so that the volume of the traditional optical module is large, the electric power consumption and the optical loss are large, the low processing cost is difficult to realize in the traditional semiconductor (IC) industry, the market share is difficult to improve, and the market application is not easy to realize.

Si devices based on carrier injection are capable of electrical modulation at high speed, but their optical losses are much higher than their intrinsic Si devices; (Al) GaAs has a high χ (2) nonlinearity and generates a second harmonic, but its electro-optic effect (r41 ═ 1.5 × 10)^-12mV^-1) Weak and therefore, the simultaneous on-chip generation and electrical tuning of the optical comb signal has heretofore been limited by thermal effects and the high voltage signals required. Although the prior art has the problem of heterogeneous integration of photonic chips with different functions, this solution requires the establishment of scalable, low-loss optical links between chips, which is a challenge.

The present application aims to provide an optical module that can integrate the plurality of devices into a monolithic optical module, and realize monolithic integration and miniaturization of the plurality of devices, thereby reducing the electrical power consumption and optical loss of the optical module.

The on-chip integrated lithium niobate multi-wave composite processing device is mainly applied to the transmitting end of an optical module, so that the size of the optical module is reduced.

The on-chip integrated lithium niobate multi-wave composite processing device provided by the application utilizes the second-order and third-order performances of lithium niobate to prepare an annular resonant cavity, a differential filter and an electro-optical modulator on a lithium niobate thin film and connects the devices by using optical waveguides. After a single broad spectrum laser is input to the composite processing device, the laser enters the optical frequency comb generator after passing through the annular resonant cavity, n spectral lines with discrete frequencies are obtained through n differential filters, finally, electro-optical modulation is carried out on the n spectral lines through the electro-optical modulator, n modulated optical signals can be obtained, the n modulated optical signals are combined to the tail end port through the optical waveguide, the combined optical signals are optical signals output by the optical module, and signal transmission can be carried out by externally connecting an optical fiber to the tail end port.

The scheme provided by the application is through lithium niobate (LiNbO)₃LN), in particular LiNbO₃Simultaneously has larger chi (3) (1.6 multiplied by 10)^-21m²V^-2) And χ (2) (r33 ═ 3 × 10^-11mV^-1) Moreover, chi (3) and chi (2) are both nonlinear, so that the challenge of integrating the nano photonic waveguide, the micro-ring resonator, the filter and the modulator on a single chip to realize the chi (2) function is solved. Specifically, the Kerr frequency comb is generated by chi (3) nonlinearity, and the generated frequency comb is further manipulated by an external electric field by chi (2) nonlinearity (i.e., electro-optic effect) of LN.

Fig. 1 shows a schematic diagram of the principle of the on-chip integrated lithium niobate multi-wave complex processing device, as shown in fig. 1, a single broad-spectrum laser is input into the on-chip integrated lithium niobate multi-wave complex processing device at an a-terminal, an optical frequency comb is obtained at a B-terminal after passing through a ring-shaped resonant cavity, in this application, the optical frequency comb refers to a spectrum consisting of a series of frequency components uniformly spaced and having a coherent stable phase relationship on the spectrum, and n spectral lines with separate frequencies are obtained by n differential filters, wherein the specific value of n can be selected according to the comb number and interval of the optical frequency comb, and finally, the electro-optical modulator is used for electro-optical modulation of signals of the n optical spectrums, the optical waveguide is used for combining the n optical signals to the tail end port of the optical module, and the tail end port is externally connected with an optical fiber for signal transmission. The basic scheme of on-chip integration of the multi-wave generating, modulating and multiplexing device is realized through the scheme.

In this example, the on-chip integrated lithium niobate multiwave composite processing device includes: the waveguide comprises a waveguide substrate 1, and a micro-ring resonant cavity 2, a plurality of differential filters 3 and a plurality of electro-optical modulators 4 which are integrated on the waveguide substrate 1, wherein the micro-ring resonant cavity 2 is connected with the plurality of differential filters 3 in series, each differential filter 3 is respectively communicated with one electro-optical modulator 4, and the tail ends of the electro-optical modulators are combined into the same output port.

In the present application, the waveguide substrate 1 in the on-chip integrated lithium niobate multi-wave composite processing device is prepared from lithium niobate. It is well known to those skilled in the art that lithium niobate is an artificially synthesized negative uniaxial crystal having high piezoelectric coefficient, ferroelectric coefficient, and acousto-optic coefficient. In addition, the lithium niobate has the following advantages: firstly, the lithium niobate crystal has a high electrooptical coefficient, and the half-wave voltage required by the unit length of the lithium niobate crystal is low, so that a device using the lithium niobate as a waveguide substrate has long service life and stable working performance; secondly, the optical waveguide made of the lithium niobate crystal can be directly coupled with the optical fiber, and the coupling loss is low; thirdly, the waveguide substrate made of lithium niobate can realize zero chirp signal modulation, the waveguide is hardly limited by optical fiber dispersion, and the waveguide is suitable for signal transmission of high-speed and long-distance single-mode optical fibers, particularly the field of optical fiber communication with the working wavelength of 1550 nm; and finally, the lithium niobate is used for manufacturing a waveguide matrix and is combined with a traveling wave electrode structure, so that the working speed of the waveguide matrix is very high.

In the present example, the waveguide substrate 1 is a thin film waveguide, and the applicant has found that the thin film waveguide has a large refractive index contrast as compared with a diffusion waveguide, specifically, the thin film waveguide generally uses silica as a substrate, while the diffusion waveguide is composed of a diffusion layer and a non-diffusion layer, and both the diffusion layer and the non-diffusion layer are made of lithium niobate, however, the difference between the refractive indexes of lithium niobate and silica is about 0.7, and the difference between the refractive indexes of the diffusion layer and the non-diffusion layer of the lithium niobate diffusion waveguide is about 0.01.

Fig. 2a shows a schematic structural diagram of a micro-ring resonator of the present embodiment, and fig. 2b shows a schematic principle diagram of a micro-ring resonator, where, as shown in fig. 2a and fig. 2b, a radius of the micro-ring resonator 2 is 2 μm to 200 μm, preferably 60 μm to 100 μm; q value greater than 10⁵Preferably greater than 10⁶。

In this example, if the optical path difference generated after the optical wave surrounds one circle in the micro-ring is an integral multiple of the wavelength, the optical wave interferes with the optical wave newly coupled into the micro-ring resonator 2 to generate the resonance enhancement effect, which can be specifically expressed by the following formula (1):

2πRn_cas m lambda type (1)

Wherein R represents the resonance radius of the micro-ring, n_cWhich represents the refractive index of the effective mode of the light wave in the lithium niobate, m represents the resonance order, and lambda represents the wavelength of the light wave.

From the above formula (1), the resonance radius R of the microring can be calculated as the following formula (2):

R＝mλ/2πn_cformula (2)

In this example, assume that the wavelength is represented by λ₁To lambda₂The available frequency combs can be generated, and the number of frequency combs N can be calculated according to the following formula (3):

N＝(λ₂-λ₁) /FSR formula (3)

Where FSR denotes the Free Spectral Range, in particular, for different resonance orders m, for a given resonance radius R, there is a series of wavelengths of light that satisfy the resonance condition, in which the difference in wavelength between two adjacent resonance wavelengths is called the Free Spectral Range (FSR).

Further, the FSR may be calculated according to the following formula (4):

FSR＝λn_c/mn_gformula (4)

Wherein λ represents the wavelength of the light wave, n_gRepresenting the group index of refraction of the medium within the cavity and m representing the order of resonance.

Micro-ring resonant Kerr optical frequency combs have been implemented in the prior art on some material platforms, for example, silicon dioxide (SiO)₂) Silicon nitride (SiN), silicon (Si), crystalline fluorides, diamond, aluminum nitride (AlN) and aluminum gallium arsenide (AlGaAs), etc., although they have a large χ (3) nonlinearity and low optical loss required for Kerr optical frequency combs, they have a small, even zero, χ (2) nonlinearity, and thus they are not suitable for integrating the χ (2) component on a chip.

Fig. 3a shows a schematic structural diagram of a differential filter of the present example, and fig. 3b shows a schematic diagram of the differential filter, and as shown in fig. 3a and fig. 3b, the differential filter 3 includes a filter ring 31 and a bus waveguide 32.

In this example, the modulation voltages of the respective differential filters 3 are different, so that the respective differential filters 3 realize frequency selection of different frequency bands.

In this example, the N frequency combs generated from the micro-ring resonator are selected to have the required N wavelengths according to the signal transmission requirement.

In the example, the free spectral range of the differential filter is larger than that of the micro-ring resonant cavity through electro-optical modulation, and a single spectral line with a larger optical bandwidth can be obtained by slightly electro-optically adjusting the free spectral range by utilizing the vernier caliper effect.

In this example, the filter ring in the micro-ring resonant cavity is over-coupled with the add/drop bus waveguide having the same coupling strength, so as to ensure a higher extinction ratio, and if the input light resonates with the filter, the input light with the wavelength can enter the differential filter, and finally, the input light is output through the D port, thereby realizing the function of frequency selection.

FIG. 4a is a schematic diagram showing the structure of an electro-optic modulator of the present example, and FIG. 4b is a schematic diagram showing the principle of the electro-optic modulator; as shown in fig. 4a and 4b, the electro-optical modulator 4 is a mach-zehnder electro-optical modulator for loading signals onto optical waves with different frequencies.

In this example, the light wave entering the electro-optic modulator is the light output by the front differential filter.

In this example, the two branches of the mach-zehnder electro-optic modulator are two lithium niobate optical waveguides, and in particular, the two lithium niobate optical waveguides are formed by a 50: 50Y-junction, thereby splitting the input light into two equal LN optical waveguides forming the branches of the mach-zehnder electro-optic Modulator (MZI).

In this example, the microwave electric fields have opposite directions on the two waveguides, so that optical phase delay is achieved on one waveguide arm, optical phase advance is achieved on the other arm, and finally constructive and destructive interference is achieved through the output 50: 50Y-shaped solid, resulting in an amplitude modulated optical signal.

In this example, the mach-zehnder electro-optic modulator can adjust the refractive index of the material by using a mach-zehnder interference effect and a linear electro-optic effect (i.e., a Pockels effect, second-order nonlinearity), and finally, the output optical power changes with the change of the applied voltage by using the structure of the mach-zehnder interferometer.

Specifically, the mach-zehnder electro-optic modulator is an optical modulator manufactured by using a mach-zehnder interference effect and an electro-optic effect, which divides input light into two equal paths of signals, and the phase of each path of signal changes along with the change of an external electric signal, so that the light intensity after interference combination also changes along with the change of the electric signal, and the adjustment of the light intensity is realized.

One common optical effect in the art is the Pockels effect, which is a linear electro-optic effect, specifically, the change in refractive index is proportional to the magnitude of the applied electric field.

For the Pockels effect, the coefficient of the refractive index changing with the electric field is proportional to the nonlinear coefficient r33, and because the lithium niobate material has a higher r33 coefficient, the lithium niobate material is preferably used for electro-optical modulation.

Another common electro-optic effect, the Kerr effect, is a quadratic electro-optic effect, in particular, the change in refractive index is proportional to the square of the electric field.

In this example, the metal strips disposed between the mach-zehnder electro-optic modulators are traveling wave electrodes across which a varying voltage is applied to generate microwaves.

The traveling wave electrode is loaded on the traveling wave electrode to modulate the optical field, so that the co-transmission of the microwave and the optical field is realized, and the microwave and the optical field have matched group velocity and low transmission loss. In this example, all the electro-optic modulators 4 are arranged in a row due to the large number of modulators, so that one grounded electrode can be shared between the two modulators, thereby reducing the chip size and saving material.

Further, two adjacent electro-optical modulators 4 share one ground electrode.

In this example, the number of transmitted signals is increased by loading the signals separately at each frequency using an electro-optical modulator, and the microwaves and optical fields are co-transmitted with confinement using traveling wave electrodes, with matched group velocity and low propagation loss.

The application also provides a method for preparing the on-chip integrated lithium niobate multi-wave composite processing device, which comprises the following steps:

step 1, preparing a waveguide structure on a polished single crystal lithium niobate thin film, wherein the single crystal lithium niobate thin film is provided with a silicon dioxide substrate;

step 2, preparing a micro-ring resonant cavity, a differential filter and an electro-optical modulator on the waveguide structure;

step 3, depositing metal layers used as electrodes at corresponding positions of the micro-ring resonant cavity, the differential filter and the electro-optical modulator;

step 4, plating SiO on the micro-ring resonant cavity, the differential filter, the electro-optical modulator and the metal layer₂And (3) a layer.

And the packaged optical fiber can be used as a wavelength division multiplexing device.

In the present application, the single-crystal lithium niobate thin film having a silica substrate may be commercially available.

In the present example, SiO is used₂A monocrystal lithium niobate thin film with the thickness of several microns is obtained on a substrate through dry etching/wet etching/mechanical polishing to obtain the lithium niobate thin film, a lithium niobate waveguide structure comprising a micro-ring resonant cavity, a differential filter and an electro-optical modulator is obtained, a metal layer is deposited on the corresponding positions of the structures of the micro-ring resonant cavity, the differential filter, the electro-optical modulator and the like to be used as an electrode structure, and finally a layer of SiO is plated on the micro-ring resonant cavity, the differential filter, the electro-optical modulator and the metal layer₂And the layer can be used as a wavelength division multiplexing device after being packaged.

The on-chip integrated lithium niobate multi-wave composite processing device can be manufactured on a lithium niobate composite wafer to form a centimeter-level chip, and the main service life of the on-chip integrated lithium niobate multi-wave composite processing device depends on a used laser; in contrast, the service life of the conventional optical module is also dependent on the laser lifetime, because the volume of the conventional optical module is at least 5 times or more of the three-dimensional structure. However, the number of parts in the conventional laser is large, and the whole laser is damaged as long as one part is damaged, so that the service life of the laser manufactured by using the on-chip integrated lithium niobate multi-wave composite processing device provided by the application is relatively longer.

Compared with the prior art, the on-chip integrated lithium niobate multi-wave composite processing device can obtain a plurality of electro-optic modulation information with different wavelengths on one chip, and can realize wavelength division multiplexing after the tail end is lumped, so that the volume of the device is greatly reduced; the on-chip integrated lithium niobate multi-wave composite processing device only uses one laser, has small heat production and high electro-optic modulation rate, so that the cost and the volume of the optical module can be greatly reduced by applying the on-chip integrated lithium niobate multi-wave composite processing device to the transmitting end of the optical module, the working efficiency and the stability are improved, and a plurality of functional devices are integrated on the lithium niobate wafer by the on-chip integrated lithium niobate multi-wave composite processing device provided by the application, so that the average cost is reduced, the power consumption in the using process is reduced, and the global large-scale production is realized.

The present application has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to limit the application. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the presently disclosed embodiments and implementations thereof without departing from the spirit and scope of the present disclosure, and these fall within the scope of the present disclosure. The protection scope of this application is subject to the appended claims.