CN-121995578-A - Multi-state adjustable waveguide mode converter with single-port input/output and preparation method thereof

CN121995578ACN 121995578 ACN121995578 ACN 121995578ACN-121995578-A

Abstract

The invention provides a single-port input/output polymorphic adjustable waveguide mode converter and a preparation method thereof, belonging to the technical field of on-chip silicon-based polymer hybrid integrated waveguide mode converters. The invention adopts a double-layer MZI parallel combination structure, and realizes accurate regulation and control of an input light field by configuring an independent electrode at a specific position of an interference arm and applying a corresponding modulation signal. When E 00 mode signal light is input, the structure can dynamically realize three mode conversion functions of E 00 /E 01 /E 10 on the premise of maintaining single-port output, and the mode conversion efficiency reaches 95%. And the device is compatible with a standard silicon-based CMOS process, is beneficial to reducing the manufacturing cost and promoting large-scale integration application, is suitable for the fields of high-capacity mode division multiplexing systems and multidimensional optical signal processing, and can meet the urgent requirements of modern optical communication on high-integration-level, reconfigurable operation and low-cost devices.

Inventors

CAO YUE
YU WEI
WANG SHOUYU
ZHAI RUIZHAN
LIU MINZHE
TIAN XIAOLIN
GUO WEI

Assignees

无锡学院
山东省科学院激光研究所

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The single-port input/output polymorphic adjustable waveguide mode converter is characterized by comprising a substrate layer, a first cladding layer, a second cladding layer and a third cladding layer which are sequentially stacked, and further comprising a double-layer MZI core layer, wherein the double-layer MZI core layer comprises a first MZI core layer and a second MZI core layer, and the double-layer MZI core layer is of a single-port input and single-port output waveguide structure; the first MZI core layer is embedded in the second cladding layer, and the thickness of the second cladding layer is the same as that of the first MZI core layer; one MZI structure is respectively nested on the interference arms of the first MZI core layer and the second MZI core layer; The first MZI core layer comprises a first core layer first interference arm waveguide, a first core layer second interference arm waveguide and a first core layer third interference arm waveguide, and the first core layer second interference arm waveguide and the first core layer third interference arm waveguide are positioned in a nested MZI structure; the second MZI core layer comprises a second core layer first interference arm waveguide, a second core layer second interference arm waveguide and a second core layer third interference arm waveguide, and the second core layer second interference arm waveguide and the second core layer third interference arm waveguide are positioned in the nested MZI structure; The first partial electrode is arranged above at least one of the first core layer first interference arm waveguide and the second core layer first interference arm waveguide, the first partial electrode is arranged on the surface of the second cladding layer, the second partial electrode is arranged on the surface of at least two of the first core layer second interference arm waveguide, the first core layer third interference arm waveguide, the second core layer second interference arm waveguide and the second core layer third interference arm waveguide, and at least one of the second partial electrode above the first core layer second interference arm waveguide and the first core layer third interference arm waveguide, and at least one of the second partial electrode above the second core layer second interference arm waveguide and the second core layer third interference arm waveguide is arranged on the surface of the third cladding layer.
2. The multi-state tunable waveguide mode converter of claim 1, wherein the first core first interference arm waveguide and the second core first interference arm waveguide are each provided with a first partial electrode above.
3. The multi-state tunable waveguide mode converter of claim 1, wherein surfaces of two of the first core second interference arm waveguide, the first core third interference arm waveguide, the second core second interference arm waveguide, and the second core third interference arm waveguide are provided with second partial electrodes.
4. The multi-state tunable waveguide mode converter of claim 1, wherein the first and second MZI core layers are the same material and refractive index.
5. The polymorphic tunable waveguide mode converter of claim 1, wherein the first and second MZI core layers are Si, si 3 N 4 , SU-8 series photoresist, NR series photoresist, AZ series photoresist, or EPOCore photoresist.
6. The multi-state tunable waveguide mode converter of claim 1, wherein the first core first interference arm waveguide has a thickness of 2-24 μm and a width of 2-20 μm, and the first core second interference arm waveguide and the first core third interference arm waveguide have a thickness of 2-24 μm and a width of 1-10 μm independently; the thickness of the second core layer first interference arm waveguide is 2-24 microns, the width of the second core layer first interference arm waveguide is 2-20 microns, the thicknesses of the second core layer second interference arm waveguide and the second core layer third interference arm waveguide are 2-24 microns independently, and the widths of the second core layer second interference arm waveguide and the second core layer third interference arm waveguide are 1-10 microns independently.
7. The polymorphic tunable waveguide mode converter of claims 1 or 6, wherein the first partial electrode has a thickness of 100-300 nm and a width of 5-30 μm, and the second partial electrode has a thickness of 100-300 nm and a width of 3-15 μm.
8. The tunable multi-mode waveguide converter of claim 1 or 6, wherein the first cladding layer has a thickness of 2-24 μm, the second cladding layer has a thickness of 2-24 μm, and the third cladding layer has a thickness of 1-10 μm.
9. The tunable multi-state waveguide mode converter of claim 1, wherein the materials of the first cladding layer, the second cladding layer, and the third cladding layer independently comprise one or more of SiO 2 , polymethyl methacrylate, polystyrene, epoClad, hydrogel, polydimethylsiloxane, and NOA series.
10. The method for manufacturing a single-port input/output multi-mode tunable waveguide mode converter according to any one of claims 1 to 9, comprising the steps of: Coating a first MZI core layer material, first photoetching, first exposure and first development on the surface of the substrate layer in sequence to form a first MZI core layer; Coating a first cladding material on the periphery of the first MZI core layer to form a first cladding; Coating a second MZI core layer material, second photoetching, second exposure and second development on the surface of the first cladding layer in sequence to form a second MZI core layer; coating a second cladding material on the periphery of the second MZI core layer to form a second cladding; Depositing a first metal film on the surface of the second cladding layer, sequentially performing third photoetching, third exposure and third development on the surface of the first metal film to form an electrode in the first MZI core layer, and then coating a third cladding material on the surface of the obtained sample to form the third cladding layer; And depositing a second metal film on the surface of the third cladding layer, and then sequentially carrying out fourth photoetching, fourth exposure and fourth development on the surface of the second metal film to form an electrode in the second MZI core layer, thereby obtaining the single-port input/output multi-state adjustable waveguide mode converter.

Description

Multi-state adjustable waveguide mode converter with single-port input/output and preparation method thereof Technical Field The invention relates to the technical field of on-chip silicon-based polymer hybrid integrated waveguide mode converters, in particular to a single-port input/output multi-state adjustable waveguide mode converter and a preparation method thereof. Background Along with the increasing development of the communication technology, the photonic integrated device on the silicon substrate integrates a plurality of devices such as a laser, a modulator, a waveguide, a detector and the like on a single chip, has the advantages of large-scale integration of a CMOS (complementary metal oxide semiconductor) process and the characteristics of high bandwidth, low power consumption and interference resistance of optical signals, effectively improves the data transmission rate, and provides an indispensable technical path for the development of the fields such as data centers, high-performance calculation and the like. However, as the communication requirement is continuously increased, the conventional single-mode waveguide structure is difficult to meet the requirement of ultra-high density integration, and the functional expansion of the chip-level photonic device is restricted. The multiplexing technology (Mode Division Multiplexing, MDM) uses different space modes in the waveguide as independent transmission channels, and simultaneously transmits multiple signals on the same wavelength, thereby effectively improving the transmission capacity of the communication system. The mode division multiplexing system consists of a plurality of key devices, including a mode converter, a mode multiplexer, a few-mode optical fiber, a mode demultiplexer and the like. The mode converter is used as a core device of the MDM system and can realize the energy exchange function between the basic mode and the high-order mode. The optical waveguide mode converter can be divided into a single-port output type and a multi-port output type according to different configurations of output ports, and common structures of the single-port output mode converter include an asymmetric directional coupler, a Mach-Zehnder interferometer (MZI), a Bragg grating, a conical structure and the like. The asymmetric directional coupler consists of two parallel waveguides, and the coupling and mode conversion of the optical signals between the two waveguides in the coupling area are realized by controlling the parameters such as the distance, the length, the refractive index and the like of the waveguides. The MZI mode converter structure can realize mode conversion by controlling the sizes of two interference arms and adjusting the optical path difference of two different paths. The Bragg grating mode converter introduces periodic refractive index change in the waveguide, and changes the intensity and the phase of input signal light by meeting the phase matching condition among different modes, thereby realizing the transfer of light energy among different modes. The taper structure mode converter adopts a longitudinal nonuniform coupling design, and realizes conversion from few modes to multiple modes by optimizing a taper port structure. However, for the single-port output mode converter mentioned above, only a single mode to single mode conversion can be realized after the device structure is determined, and the function of the complex mode division multiplexing system which needs to process multiple modes at the same time is single. The multi-port output mode converter can distribute a single input optical signal to a plurality of output ports and synchronously realize a mode conversion function, for example, related technology realizes the output of a single-port E11 input to a dual-port E21 mode and an E22 mode by designing a Y-branch waveguide structure, but only can synchronously realize one mode conversion in a plurality of output ports, and an adjustable 7-port mode coupler is disclosed as related technology, so that the conversion from a TE0 mode to a TE1 mode or a TE2 mode can be realized, but the multi-port output waveguide structure has a large size, is unfavorable for high-density integration, and the parallel ports can generate a mode crosstalk problem during transmission. Therefore, although research on single-port and multi-port output mode couplers has been advanced, single-port mode couplers are often focused on specific mode conversion, so that single performance is realized. The multi-port mode coupler can realize multi-mode output, but has a complex structure and has the problems of crosstalk, uneven energy distribution and the like. Therefore, the waveguide mode converter integrating single-port output, multi-mode flexible and adjustable and compact structure into a whole is still lacking in the technical field of on-chip photon integration. Disclosure of Invention Accordingly, the present invention is directed t