Optical Waveguide Floating Gate for Nonvolatile Photonic Memory

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Solution Overview

Problem

Conventional photonic circuits are incapable of functioning as nonvolatile memory, limiting their applications in low-power and high-performance computing.

Innovation Solution

Incorporating an optical waveguide as a floating gate that is charged or discharged via quantum tunneling through an insulator layer, allowing it to retain a nonvolatile charge state, which modulates the refractive index and functions as a nonvolatile optical switch or memory cell.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional photonic circuits are used, then optical signal transmission is achieved, but nonvolatile memory functionality is lost

Engineering Contradiction:
Improvememory functionalityVSAvoiddata retention
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent merges the optical waveguide structure with the floating gate memory structure by forming the floating gate from the waveguide core material. This integration allows the same physical structure to serve dual purposes: guiding optical signals and storing electrical charge nonvolatily, thereby combining photonic circuit functionality with memory capabilities in a single component.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The optical waveguide is designed to perform multiple functions simultaneously: it acts as both an optical signal transmission medium and a nonvolatile memory storage element. The floating gate portion of the waveguide can store charge states that modulate the refractive index, enabling the structure to function as both a photonic component and a memory cell.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If semiconductor circuits are used for memory, then nonvolatile storage is achieved, but power consumption increases

Engineering Contradiction:
Improvedata retentionVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces conventional electrical readout mechanisms with optical detection. The charge state of the floating gate is read by measuring changes in optical transmission or phase through the waveguide, rather than requiring electrical sensing circuits. This substitution eliminates the need for continuous power supply to maintain memory states and enables optically-powered or ultra-low-power memory operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 waveguide serves as a nonvolatile memory element, enabling low-power operation and stable state maintenance without electrical power consumption, suitable for various computing tasks including machine learning and data storage.

Implementation Method 1

The waveguide may be configured to confine an optical field utilizing total internal reflection

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The photonic circuit may include an optical waveguide and a photodetector

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4249999B1Solid-state device with optical waveguide as floating gate electrode
Publication Date: 2026.03.25 ORCA COMPUTING LTD
  • EP4249999B1 patent drawingFigure 1
  • EP4249999B1 patent drawingFigure 2A~2B
  • EP4249999B1 patent drawingFigure 3A

AI summary

A semiconductor device includes a floating gate that can be charged in a nonvolatile manner. The floating gate is also structured as an optical waveguide, and maybe optically coupled to a photonic circuit, such as an interferometer.