CN-114326167-B - Electro-optical modulator and electro-optical modulation method

CN114326167BCN 114326167 BCN114326167 BCN 114326167BCN-114326167-B

Abstract

The invention relates to the field of optical communication and provides an electro-optical modulator and an electro-optical modulation method, wherein the electro-optical modulator comprises an optical input interface, a first nano beam cavity connected with the optical input interface, a second nano beam cavity coupled with the first nano beam cavity and an optical output interface connected with the second nano beam cavity, a first PN junction is arranged on the first nano beam cavity, a second PN junction is arranged on the second nano beam cavity, and the first PN junction and the second PN junction are used for adjusting the coupling of the first nano beam cavity and the second nano beam cavity after loading a single-ended push-pull electrode and controlling the light intensity output from the optical output interface. According to the invention, the two waveguides are powered to adjust the coupling between the resonant cavities, so that the light output in the lower waveguide is controlled, the scattering of the waveguide and the modulator size can be reduced, the high Q value is realized, and the frequency selecting function is realized.

Inventors

LI CAN
ZHOU GANGQIANG
LU LIANGJUN
CHEN JIANPING
GAO YUQI

Assignees

中兴通讯股份有限公司
上海交通大学

Dates

Publication Date: 20260505
Application Date: 20201010

Claims (10)

1. An electro-optic modulator, comprising: The device comprises an optical input interface, a first nano-beam cavity connected with the optical input interface, a second nano-beam cavity coupled with the first nano-beam cavity, and an optical output interface connected with the second nano-beam cavity; The first nano beam cavity is provided with a first PN junction, the second nano beam cavity is provided with a second PN junction, and the first PN junction and the second PN junction are used for adjusting the coupling between the first nano beam cavity and the second nano beam cavity after loading the single-ended push-pull electrode, so as to control the light intensity output from the light output interface.
2. The electro-optic modulator of claim 1, wherein the first nanobeam cavity is juxtaposed with the second nanobeam cavity, the electro-optic modulator further comprising: The first high doping area is positioned at the first side of the first nano-beam cavity, wherein the first side is the side away from the second nano-beam cavity; A second highly doped region located between the first and second nanobeam cavities; The third high doping region is positioned at the second side of the second nano-beam cavity, wherein the second side is the side away from the first nano-beam cavity; the first high doping region and the third high doping region are used for being connected with a microwave signal forming the single-ended push-pull electrode, and the second high doping region is used for being connected with a direct current signal forming the single-ended push-pull electrode.
3. An electro-optic modulator as claimed in claim 2 wherein the first highly doped region is a P-type doped region, the second highly doped region is an N-type doped region, and the third highly doped region is a P-type doped region.
4. The electro-optic modulator of claim 2, further comprising a first metal electrode and a second metal electrode; The first metal electrode is connected with the first high doping region and the third high doping region and is used for connecting the microwave signal into the first high doping region and the third high doping region; The second metal electrode is connected with the second high doping area and is used for connecting the direct current signal into the second high doping area.
5. The electro-optic modulator of claim 1, wherein the first and second nanobeam cavities are asymmetric nanobeam cavities.
6. The electro-optic modulator of claim 5, wherein the ratio of the air holes at the two ends of the first and second nano-beam cavities is 2:1, wherein the number of air holes at the end of the first nano-beam cavity near the light input interface is smaller than the number of air holes at the end far from the light input interface, and the number of air holes at the end of the second nano-beam cavity near the light output interface is smaller than the number of air holes at the end far from the light output interface.
7. An electro-optic modulator as claimed in claim 6 wherein, The aperture of the air hole at one end of the first nano-beam cavity, which is far away from the optical input interface, gradually changes from large to small in the direction facing the optical input interface; the aperture of the air hole at one end of the second nano-beam cavity, which is close to the light output interface, gradually changes from large to small in the direction towards the light output interface, and the aperture of the air hole at one end of the second nano-beam cavity, which is far away from the light output interface, gradually changes from large to small in the direction away from the light output interface.
8. The electro-optic modulator of claim 7, wherein the number and size of air holes in the first and second nano-beam cavities is set according to a desired extinction ratio of light output from the light output interface.
9. An electro-optic modulator as claimed in any one of claims 1 to 8 wherein the optical input interface is implemented with a grating coupler or an inverted cone coupler; the light output interface is realized by adopting a grating coupler or an inverted cone coupler.
10. An electro-optic modulation method as claimed in any one of claims 1 to 9, comprising: Transmitting laser to an optical input interface of the electro-optic modulator, wherein the laser enters a first nano-beam cavity of the electro-optic modulator through the optical input interface; and electrifying a first PN junction on the first nano-beam cavity and a second PN junction on the second nano-beam cavity of the electro-optical modulator through a single-ended push-pull electrode to obtain modulated light.

Description

Electro-optical modulator and electro-optical modulation method Technical Field The invention relates to the field of integrated optical communication, in particular to a silicon-based integrated electro-optical modulator based on coupling modulation. Background The silicon-based photonic device has the advantages of high bandwidth and high speed, is compatible with the traditional microelectronic process, and can well realize photoelectric fusion, so that silicon-based optoelectronics is rapidly developed as an emerging subject and plays an important role in the communication field. Among them, silicon-based modulators as electro-optical conversion core devices have been widely studied. In silicon-based modulators, the carrier concentration in a silicon waveguide is typically changed by the action of an applied electric field, thereby changing the refractive index and absorption coefficient of the waveguide, and thus the phase of the transmitted light in the waveguide, and converting the phase change into a light intensity change by an interference structure or a resonant cavity structure. Typical optical structures for electro-optic modulators are Mach-Zehnder interferometers (MZI) type and micro-ring resonators (MRR) type. In the MRR modulator, the incident light enters a straight waveguide and is partially coupled into a micro-ring, and the light field of the straight waveguide and the light field coupled out from the micro-ring and entering the straight waveguide are overlapped by interference to form the light field of the output light. The quality factor Q of the existing silicon-based integrated electro-optic modulator is low, the scattering of the waveguide and the size of the modulator are large, and the power consumption is large. Disclosure of Invention The embodiment of the invention provides an electro-optical modulator and an electro-optical modulation method, which are characterized in that the coupling between resonant cavities is adjusted by powering up two waveguides, the light output in the lower waveguide is controlled, the scattering of the waveguide and the modulator size can be reduced, the high Q value is realized, and the frequency selection function is realized. In order to solve the technical problems, the embodiment of the invention provides an electro-optical modulator, which comprises an optical input interface, a first nano beam cavity connected with the optical input interface, a second nano beam cavity coupled with the first nano beam cavity, and an optical output interface connected with the second nano beam cavity, wherein a first PN junction is arranged on the first nano beam cavity, a second PN junction is arranged on the second nano beam cavity, and the first PN junction and the second PN junction are used for adjusting the coupling of the first nano beam cavity and the second nano beam cavity after loading a single-ended push-pull electrode and controlling the light intensity output from the optical output interface. The embodiment of the invention also provides an electro-optic modulation method, which comprises the steps of emitting laser to an optical input interface of the electro-optic modulator, enabling the laser to enter a first nano-beam cavity of the electro-optic modulator through the optical input interface, and electrifying a first PN junction on the first nano-beam cavity and a second PN junction on a second nano-beam cavity of the electro-optic modulator through a single-ended push-pull electrode to obtain modulated light. Compared with the prior art, the embodiment of the invention provides an electro-optical modulator structure based on a coupling modulation nano-beam cavity, which comprises two waveguides of the coupling nano-beam cavity, wherein single-ended push-pull electrodes are loaded on the two waveguides, and the effective refractive indexes of the two waveguides are respectively changed by applying voltage, so that the coupling between resonant cavities is regulated, the output ratio of light from a lower waveguide is controlled, and the electro-optical coupling is realized. Because the waveguide is two coupled nano beam cavities, the scattering of the waveguide and the size of a modulator can be reduced, the high-Q-value is realized, and the frequency selection function is realized. Drawings Fig. 1 is a schematic diagram of an electro-optic modulator according to a first embodiment; FIG. 2 is a schematic diagram of an electro-optic modulator according to a second embodiment; FIG. 3 is a schematic diagram of an electro-optic modulator according to a third embodiment; FIG. 4 is a transmission line of an optical output port of an electro-optic modulator according to a third embodiment without power-up modulation; FIG. 5 is a transmission line of an optical output port under power-on modulation of an electro-optic modulator according to a third embodiment; fig. 6 is a flowchart of an electro-optical modulation method according to a fourth embod