Optical Antenna Grating Protrusions for Wide-Angle Emission

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional optical grating couplers in photonic integrated circuits (PICs) have a limited range of emission angles, restricting the field of view and signal fidelity, particularly in applications like LiDAR.

Innovation Solution

An optical antenna for PICs is designed with a semiconductor waveguide having opposing vertical sidewalls and horizontally extending grating protrusions, along with a dielectric layer and a nitride waveguide, allowing for wider angular transmission of optical signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional grating couplers are used to connect photonic waveguides, then the device structure is simple and easy to manufacture, but the range of emission angles is limited and the field of view is restricted

Engineering Contradiction:

Improverange of emission anglesVSAvoidoptical antenna structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The optical antenna is segmented into multiple grating protrusions extending from the semiconductor waveguide sidewall. Each grating protrusion acts as an independent optical element that contributes to the overall angular transmission capability, allowing the structure to achieve wide emission angles through distributed grating elements rather than a single conventional coupler

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from planar grating couplers to three-dimensional grating protrusions that extend vertically from the waveguide sidewall. This dimensional change enables the optical antenna to interact with light in multiple spatial dimensions, achieving enhanced angular coverage and field of view that cannot be obtained with conventional two-dimensional grating structures

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If conventional grating couplers with limited emission angles are used, then the device complexity is low, but the signal fidelity is insufficient for applications like LiDAR

Engineering Contradiction:

Improvesignal fidelityVSAvoidoptical antenna structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The grating protrusions are positioned specifically on the sidewall of the semiconductor waveguide, creating localized optical modulation zones. This local quality enhancement at the waveguide-perpendicular interface enables superior signal fidelity for wide-angle transmission without requiring complex modifications throughout the entire photonic circuit structure

Inventive Principle:

Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The optical antenna expands the range of transmission angles for optical signals, enhancing signal fidelity and suitability for applications such as LiDAR and photonic phased arrays.

Implementation Method 1

a first plurality of grating protrusions extending horizontally from the first vertical sidewall of the semiconductor waveguide

Methodology Applied

Scientific EffectDiffraction: Diffraction

Data Source

PatentUS11656409B2Optical antenna for photonic integrated circuit and methods to form same

Publication Date: 2023.05.23 GLOBALFOUNDRIES US INC

AI summary

Embodiments of the disclosure provide an optical antenna for a photonic integrated circuit (PIC). The optical antenna includes a semiconductor waveguide on a semiconductor layer. The semiconductor waveguide includes a first vertical sidewall over the semiconductor layer over the semiconductor layer. A plurality of grating protrusions extends horizontally from the first vertical sidewall of the semiconductor waveguide.