US-12619124-B2 - Device for switching optical signal

Abstract

Proposed is a device for switching an optical signal, the device including a first waveguide constituting an input port and a first output port; and a second waveguide constituting a second output port, wherein the first waveguide is formed of a first material, wherein the second waveguide is formed of the first material and contains a second material, wherein a gap between the first and second waveguides has a first value in a first section, a gap therebetween has a value increasing from the first value to a second value in a second section, and a gap therebetween has a third value in a third section, wherein at least one portion of the first section and at least one portion of the second section overlap in the one section, and wherein a grating structure applies to the first and second waveguides in at least one portion of the first section.

Inventors

• Jae Gyu PARK
• Sung Hoon Hong
• Soo Jung Kim

Assignees

• ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE

Dates

Publication Date

20260505

Application Date

20230518

Priority Date

20220518

Claims (19)

1. 1 . A device for switching an optical signal, the device comprising: a first waveguide constituting an input port and a first output port; and a second waveguide constituting a second output port, wherein the first waveguide has first, second and third sections and is formed of a first material, wherein the second waveguide has first, second and third sections, is formed of the first material, and contains in addition to the first material a second material that experiences phase transition according to temperature, the second material being coupled to an upper end portion of the first material in the first and second sections of the second waveguide, wherein a gap between the first waveguide and the second waveguide uniformly has a first value in the first section of the first waveguide and the first section of the second waveguide, a gap between the first waveguide and the second waveguide has a value increasing from the first value to a second value in the second section of the first waveguide and the second section of the second waveguide, and a gap between the first waveguide and the second waveguide uniformly has a third value in the third section of the first waveguide and the third section of the second waveguide, wherein at least one portion of the first section of the first waveguide overlaps at least one portion of the first section of the second waveguide, and at least one portion of the second section of the first waveguide overlaps at least one portion of the second section of the second waveguide, and wherein a grating structure applies to the first waveguide and the second waveguide in the at least one portion of the first section of the first waveguide and the at least one portion of the first section of the second waveguide.
2. 2 . The device of claim 1 , wherein the grating structure applies to the first material and the second material in the at least one portion of the first section of the first waveguide and the at least one portion of the first section of the second waveguide.
3. 3 . The device of claim 1 , wherein the grating structure is disposed at a front end of the second waveguide.
4. 4 . The device of claim 1 , wherein the grating is disposed at one end of the second waveguide.
5. 5 . The device of claim 1 , wherein the second material in the first and second sections of the second waveguide has a narrower width than a width of the first material in the third section of the second waveguide.
6. 6 . The device of claim 1 , wherein the grating structure is formed in lateral surfaces of the first waveguide and the second waveguide, the lateral surfaces facing each other.
7. 7 . The device of claim 1 , wherein the first material contains SiN, and the second material contains Ge 2 Sb 2 Te 5 (GST).
8. 8 . The device of claim 1 , wherein the grating structure is in the form of a grating with a period shorter than a wavelength of the optical signal.
9. 9 . The device of claim 1 , wherein, in a case where the optical signal is input into the input port and needs to be output to the first output port, the second material is controllable in such a manner as to be in a crystal state.
10. 10 . The device of claim 1 , wherein, in a case where the optical signal is input into the input port and needs to be output to the second output port, the second material is controllable in such a manner as to be in an amorphous state.
11. 11 . The device of claim 1 , wherein whether or not the first waveguide and the second waveguide are matched in mode with each other is determined based on a state of the second material.
12. 12 . The device of claim 11 , wherein, in a case where the second material is in an amorphous state, the first waveguide and the second waveguide are matched in mode with each other, and wherein, in a case where the second material is in a crystal state, the first waveguide and the second waveguide are mismatched in mode with each other.
13. 13 . The device of claim 11 , wherein, in a case where the second material is in an amorphous state, the first waveguide and the second waveguide are relatively less mismatched in mode with each other than in a case where the second material is in a crystal state.
14. 14 . A device for switching an optical signal, the device comprising: a first waveguide constituting a first port; a second waveguide constituting a second port; and a third waveguide constituting a third port, wherein the first waveguide is formed of a first material, wherein the second waveguide is formed of the first material, and contains, in addition to the first material, a first metamaterial as a second material that experiences phase transition according to temperature, the second material being coupled to an upper end portion of the first material in one section of the second waveguide, wherein the third waveguide is formed of the first material, and contains, in addition to the first material, a second metamaterial as the second material that experiences phase transition according to temperature, the second material being coupled to an upper end portion of the first material in one section of the third waveguide, wherein the optical signal is input into the first port and is output to one of the second port and the third port on the basis of a combination of a state of the first metamaterial and a state of the second metamaterial, wherein the first waveguide and the second waveguide have a gap that is at or below a threshold value, and a grating structure is formed in lateral surfaces of the first waveguide and the second waveguide, the lateral surfaces facing each other, and wherein the first waveguide and the third waveguide have a gap that is at or below the threshold value, and a grating structure is formed in lateral surfaces of the first waveguide and the third waveguide, the lateral surfaces facing each other.
15. 15 . The device of claim 14 , wherein the first waveguide has the first port on one end portion thereof and has a fourth port on another end portion thereof, wherein the second waveguide has the second port on one end portion thereof and has a fifth port on another end portion thereof, wherein the third waveguide has the third port on one end portion thereof and has a sixth port on another end portion thereof, wherein the optical signal that is input into the first port is output to one of the second port, the third port, and the fourth port on the basis of the combination of the state of the first metamaterial and the state of the second metamaterial, and wherein, when the optical signal is input into the fourth port, the optical signal is output to one of the fifth port, the sixth port, and the first port on the basis of the combination of the state of the first metamaterial and the state of the second metamaterial.
16. 16 . The device of claim 14 , wherein a tapered structure is formed in a region of the first waveguide, the region employing the grating structure.
17. 17 . The device of claim 14 , the device further comprising: a fourth waveguide perpendicularly intersecting the second waveguide and, along with the third waveguide, forming a structure of a directional coupler; and a plurality of switch elements, each including the first waveguide, the second waveguide, the third waveguide, and the fourth waveguide, wherein the plurality of switch elements are arranged in a two-dimensional geometric array, and wherein a plurality of optical signals that are input into switch elements, respectively, in a first column are output to switch elements, respectively, in a last column or to switch elements, respectively, in a last row, on the basis of states of first and second metamaterials contained in the plurality of switch elements, respectively.
18. 18 . The device of claim 14 , further comprising: a fourth waveguide perpendicularly intersecting the second waveguide; and a fifth waveguide, along with the third waveguide and, along with the fourth waveguide, forming a directional coupler; and a plurality of switch elements, each including a set of the first waveguide, the second waveguide, the third waveguide, the fourth waveguide, and the fifth waveguide, wherein the plurality of switch elements are arranged in a two-dimensional geometric array, wherein a plurality of optical signals that are input into switch elements, respectively, in a first column are output to switch elements, respectively, in a last column or to switch elements, respectively, in a last row, on the basis of states of metamaterials contained in the plurality of switch elements, respectively, and wherein a plurality of optical signals that are input into switch elements, respectively, in the last row are output to switch elements, respectively, in the first row or to switch elements, respectively, in the first column, on the basis of states of the metamaterials contained in the plurality of switch elements, respectively.
19. 19 . A device for switching an optical signal, the device comprising: a first waveguide constituting a first port and a second port; a second waveguide constituting a third port and a fourth port, the second waveguide perpendicularly intersecting the first waveguide; a third waveguide arranged along the first waveguide in such a manner that a region, adjacent to the first port, of the third waveguide and the first port forms a gap that is at or below a threshold value, the third waveguide further being arranged along the second waveguide in such a manner that a region, adjacent to the third port, of the third waveguide and the third port has a gap that is at or below the threshold value; a fourth waveguide arranged along the first waveguide in such a manner that a region, adjacent to the second port, of the fourth waveguide and the second port has a gap that is at or below the threshold value, the fourth waveguide further being arranged along the second waveguide in such a manner that a region, adjacent to the third port, of the fourth waveguide and the third port has a gap that is at or below the threshold value; a fifth waveguide arranged along the first waveguide in such a manner that a region, adjacent to the first port, of the fifth waveguide and the first port has a gap that is at or below the threshold value, the fifth waveguide further being arranged along the second waveguide in such a manner that a region, adjacent to the fourth port, of the fifth waveguide and the fourth port has a gap that is at or below the threshold value; and a sixth waveguide arranged along the first waveguide in such a manner that a region, adjacent to the second port, of the sixth waveguide and the second port has a gap that is at or below the threshold value, the sixth waveguide further being arranged along the second waveguide in such a manner that a region, adjacent to the fourth port, of the sixth waveguide and the fourth port has a gap that is at or below the threshold value, wherein the first waveguide and the second waveguide are formed of a first material, wherein each of the third waveguide, the fourth waveguide, the fifth waveguide, and the sixth waveguide is formed of the first material, and contains, in addition to the first material, a second material that experiences phase transition according to temperature, the second material being coupled to an upper end portion of the first material in one section, and wherein an optical signal that is input into the first port is output to one of the second port, the third port, and the fourth port on the basis of a combination of states of metamaterials contained in the third waveguide, the fourth waveguide, the fifth waveguide, and the sixth waveguide, respectively.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority from and the benefit of Korean Patent Application No. 10-2022-0060747, filed on May 18, 2022, which is hereby incorporated by reference for all purposes as if set forth herein. BACKGROUND Field Exemplary embodiments of the present disclosure relates to a device for transmitting an optical signal and, more particularly, to a device for switching an optical signal. Discussion of the Background In the fields, such as 5th generation (5G)/6th generation (6G) communication, data center, and high-performance computing (HPC), research has been actively conducted on photonics integrated circuits (PICs) that are capable of performing high-speed data processing low power consumption in order to process a sharply increasing amount of data in a large amount with less power consumption. Specifically, the results of much research on various photonics elements, such as an optical modulator, an optical switch, an optical distributor, and a polarization controller have been reported. Among these photonics elements, the optical switch is an element that serves to perform switching for transmission of a large amount of data at an ultrahigh speed without any delay over a complex optical network. Usually, the optical switch employs an N×N array structure in order to make a connection to the complex networks. The optical switches have been developed as types of PICs large-scale integrated on one chip. In order to deal with an exponentially increasing amount of data, the number of switches has been rapidly increasing. Accordingly, there has been a significant increase in power consumption by the switches. Therefore, to achieve large-scale integration and low power consumption, it is crucial to minimize the size of each photonic switch. SUMMARY Various embodiments are directed to a device for switching an optical signal in a more effective manner. Furthermore, various embodiments are directed to a device for switching an optical signal at a high speed with less power consumption. Furthermore, various embodiments are directed to a device for switching an optical signal using a small-sized element. In an embodiment, a device for switching an optical signal includes a first waveguide constituting an input port and a first output port; and a second waveguide constituting a second output port, wherein the first waveguide is formed of a first material over all sections, wherein the second waveguide is formed of the first material over the all sections and contains a second material that experiences phase transition according to temperature, the second material being coupled to an upper end portion of the first material in one section, wherein a gap between the first waveguide and the second waveguide uniformly has a first value in a first section, a gap between the first waveguide and the second waveguide has a value increasing from the first value to a second value in a second section, and a gap between the first waveguide and the second waveguide uniformly has a third value in a third section, wherein at least one portion of the first section and at least one portion of the second section overlap in the one section, and wherein a grating structure applies to the first waveguide and the second waveguide in at least one portion of the first section. In an embodiment, in the device, the grating structure may apply to the first material and the second material in at least one portion of the first section. In an embodiment, in the device, the grating structure to apply to the first waveguide may be formed by starting at a front end of the second waveguide. In an embodiment, in the device, the grating structure to apply to the second waveguide may be formed by starting at one end of the second waveguide. In an embodiment, in the device, the second material may have a narrower width than the first material. In an embodiment, in the device, the grating structure may be formed in lateral surfaces of the first waveguide and the second waveguide, the lateral surfaces facing each other. In an embodiment, in the device, the first material contains SiN, and the second material may contain Ge2Sb2Te5 (GST). In an embodiment, in the device, the grating structure may be in the form of a grating with a period shorter than a wavelength of the optical signal. In an embodiment, in the device, in a case where the optical signal that is input into the input port needs to be output to the first output port, the second material may be controlled in such a manner as to be in a crystal state. In an embodiment, in the device, in a case where the optical signal that is input into the input port needs to be output to the second output port, the second material may be controlled in such a manner as to be in an amorphous state. In an embodiment, in the device, whether or not the first waveguide and the second waveguide may be matched in mode with each other is determined based on a state of the se