Super-compact arrayed waveguide grating (AWG) wavelength division multiplexer based on sub-wavelength grating

Patent metadata

Field	Value
Publication number	US-11860411-B2
Application number	US-202217980607-A
Country	US
Kind code	B2
Filing date	Nov 4, 2022
Priority date	Mar 14, 2022
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A super-compact arrayed waveguide grating (AWG) wavelength division multiplexer based on a sub-wavelength grating is provided and includes an input waveguide, a first planar waveguide, an arrayed waveguide, a second planar waveguide, and the output waveguide that are sequentially connected. The input waveguide has 1 port, and the output waveguide has 8 ports. The arrayed waveguide includes 50 equivalent uniform strip waveguides with the same length difference, and each of the equivalent uniform strip waveguides is configured as a sub-wavelength grating structure, thereby forming the effect of increasing group refractive index or transmission delay based on a slow light effect. The 8 channels with a channel spacing of 200 GHz have the minimum adjacent channel crosstalk of less than −27 dB, and the overall size is within 300×230 μm2. In the multiplexer, the overall integration size of the device is reduced by an order of magnitude.

First claim

What is claimed is:

1. A super-compact arrayed waveguide grating (AWG) wavelength division multiplexer based on a sub-wavelength grating, comprising an input waveguide, a first planar waveguide, a sub-wavelength grating arrayed waveguide, a second planar waveguide, and an output waveguide, wherein the input waveguide, the first planar waveguide, the sub-wavelength grating arrayed waveguide, the second planar waveguide, and the output waveguide are silicon-based devices and sequentially connected;
the input waveguide has 1 port, and the output waveguide has 8 ports;
the sub-wavelength grating arrayed waveguide comprises 50 strip sub-wavelength gratings with a same length difference ΔL; each of the 50 strip sub-wavelength gratings is configured as an equivalent uniform waveguide;
the first planar waveguide and the second planar waveguide each have a basic structure of a Rowland circle, wherein the Rowland circle comprises a circle with a radius of R and an inscribed circle with a radius of R/2, and the first and second planar waveguides are symmetrically designed.

2. The super-compact AWG wavelength division multiplexer according to claim 1 , wherein a width of strip sub-wavelength gratings is 1 μm, and a diffraction order is 10; and a distance between adjacent strip sub-wavelength gratings is 1.5 μm.

3. The super-compact AWG wavelength division multiplexer according to claim 1 , a standard silicon on insulator (SOI) wafer design is employed, wherein a substrate and an upper cladding layer are each configured with a material of silicon dioxide in a thickness of 2 μm, and a main waveguide grating structure is configured with a material of silicon in a thickness of 220 nm.

4. The super-compact AWG wavelength division multiplexer according to claim 1 , the length difference ΔL of adjacent strip sub-wavelength gratings is calculated according to the following formula:

Δ
⁢
L

=

m
⁢

λ

0

n
c

,

wherein m denotes a diffraction order of AWG, λ 0 denotes a central wavelength, and n c denotes a mode effective refractive index of arrayed waveguides.

5. The super-compact AWG wavelength division multiplexer according to claim 1 , the radius R of each of the first and second planar waveguides and a diffraction order m of the AWG satisfy the following two formulas, wherein each of the first and second planar waveguides is formed by the Rowland circle:

R
≥

d
io

⁢

n
s

⁢

d
g

⁢

N

c
⁢
h

λ
0

,

m
≤

λ
0

⁢

n
c

N

c
⁢
h

⁢
Δλ
⁢

n
g

,

wherein d io denotes a distance between input and output waveguides, n s denotes a mode effective refractive index of a free propagation region waveguide, d g denotes a distance of arrayed waveguides, N ch denotes a number of output channels, λ 0 denotes a central wavelength, n c denotes a mode effective refractive index of the arrayed waveguides, Δλ, denotes a channel spacing, and n g denotes a mode group refractive index of the arrayed waveguides.

Assignees

• Univ Southwest Jiaotong

Inventors

• Zou Xihua
• Xie Changjian
• Xie Xiaojun
• Pan Wei
• Yan Lianshan

Classifications

• G02B6/12011 Primary

  characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section · CPC title

• G02B2006/12164

  Multiplexing; Demultiplexing · CPC title

• G02B6/12009 Primary

  comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides · CPC title

• G02B6/12016

  characterised by the input or output waveguides, e.g. tapered waveguide ends, coupled together pairs of output waveguides · CPC title

• G02B2006/12061

  Silicon · CPC title