Optical Modulator Heater Electrode Light Loss Reduction

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Solution Overview

Problem

Conventional optical modulators using heater electrodes for DC modulation suffer from light loss due to absorption of light by the heater electrodes and reduced heating efficiency, leading to increased electrical power consumption.

Innovation Solution

The optical device incorporates a waveguide with electro-optical and thermo-optical effects, featuring heater electrodes arranged on one side surface and parallel electrodes with high resistance on the other side surface, which are electrically connected to the heater electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If heater electrodes are arranged close to the waveguide for efficient heating, then heating efficiency is improved, but light loss increases due to absorption by the heater electrodes

Engineering Contradiction:

Improvelight lossVSAvoidheating efficiency

Core Design Contradiction:

Loss of energyVSUse of energy by stationary object

Solution Approach 1:

A parallel electrode with high resistance is introduced as an intermediary component between the heater electrode and the waveguide. This parallel electrode serves as a mediator that provides an alternative electrical path, reducing the direct absorption of light by the heater electrode while maintaining the necessary heating function through the waveguide's thermo-optical effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical resistance parameter of the parallel electrode is specifically designed to be high, which changes the electrical field distribution and current flow characteristics. This parameter change allows the system to reduce light absorption by the heater electrode while maintaining effective heating through controlled current paths, thereby resolving the contradiction between light loss and heating efficiency.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If heater electrodes are used for DC modulation, then phase control is achieved, but electrical power consumption increases

Engineering Contradiction:

Improvephase control stabilityVSAvoidelectrical power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The parallel electrode acts as an intermediary that modifies the electrical field distribution in the waveguide region. By providing a high-resistance parallel path, it enables more efficient electrical-to-thermal energy conversion directly in the waveguide, reducing the overall electrical power consumption while maintaining stable phase control through the thermo-optical effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

By changing the electrical resistance parameter of the parallel electrode to be high, the system optimizes the current distribution and heating efficiency. This parameter change allows for reduced electrical power consumption while maintaining the necessary temperature control for stable phase modulation, thus resolving the contradiction between reliability and energy consumption.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If heater electrodes are positioned to minimize light absorption, then light loss is reduced, but heating efficiency decreases

Engineering Contradiction:

Improvelight absorption lossVSAvoidheating power efficiency

Core Design Contradiction:

Loss of energyVSPower

Solution Approach 1:

The parallel electrode serves as a mediator that decouples the position of the heater electrode from its heating function. By providing an alternative electrical path with high resistance, it allows the heater electrode to be positioned for optimal light absorption minimization while still achieving effective heating through the waveguide, thus resolving the contradiction between light loss reduction and heating efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This configuration reduces light loss by minimizing absorption and enhances heating efficiency, thereby lowering electrical power consumption while maintaining stable phase control.

Implementation Method 1

heater electrode that is arranged on one of side surfaces of the waveguide and heats the waveguide

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the waveguide in which light is guided has electro-optical effect and thermo-optical effect

Methodology Applied

Scientific EffectThermo-optical effect:

Implementation Method 3

Conventional optical modulators using heater electrodes for DC modulation suffer from light loss due to absorption of light by the heater electrodes

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 4

waveguide in which light is guided

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS20250076689A1Optical device, optical transmitter, optical receiver, and optical transceiver

Publication Date: 2025.03.06 FUJITSU OPTICAL COMPONENTS LTD

AI summary

An optical device includes a waveguide in which light is guided and that has electro-optical effect and thermo-optical effect, and a heater electrode that is arranged on one of side surfaces of the waveguide and that heats the waveguide. The optical device includes a parallel electrode that is arranged on the other of the side surfaces of the waveguide, that is electrically connected to the heater electrode, and that has high resistance as compared with the heater electrode.