Multilayer Film for Silicon Photonic Modulators

Solution Overview

Problem

Silicon photonic integrated circuit devices face insufficient modulation efficiency due to the small refractive index change in silicon modulators, and electrooptic polymers suffer from long-term reliability issues, particularly photooxidation when used in fiber optic communications.

Innovation Solution

A multilayer film comprising a single-crystal silicon layer, a ZrO2 layer, and a perovskite oxide layer with an electrooptic effect is integrated into a slot waveguide, providing enhanced modulation efficiency and long-term reliability by reducing propagation loss and preventing electrical short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If electrooptic polymers are used in slot waveguides to achieve high modulation efficiency, then the electrooptic effect is enhanced, but photooxidation occurs causing deterioration of polymer materials and modulation characteristics

Engineering Contradiction:

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent uses a composite structure consisting of a dielectric layer and an electrooptic polymer layer deposited on a substrate. This composite material approach allows the dielectric layer to provide structural stability and protection against photooxidation while the electrooptic polymer layer maintains the high modulation efficiency through its electrooptic properties.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The dielectric layer acts as an intermediary between the electrooptic polymer layer and the external environment (including oxygen and light). This intermediary layer protects the electrooptic polymer from direct exposure to oxygen and strong light beams, preventing photooxidation while allowing the polymer to maintain its electrooptic function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If Si waveguides are used for optical confinement to reduce bending radius, then integration density is improved, but modulation efficiency becomes insufficient due to small refractive index change

Engineering Contradiction:

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The patent merges Si waveguide technology with electrooptic polymer materials in a hybrid structure. The Si waveguide provides strong optical confinement and tight bending radius for high integration density, while the electrooptic polymer layer integrated into the waveguide structure provides enhanced modulation efficiency through its superior electrooptic effect.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a composite waveguide structure combining silicon and electrooptic polymer materials. This composite approach allows the system to simultaneously achieve the optical confinement benefits of Si waveguides and the modulation efficiency benefits of electrooptic polymers.

Inventive Principle:

Principle #40Composite materials

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 multilayer film achieves improved modulation efficiency and long-term reliability in silicon photonic integrated circuits, enabling downsizing of optical devices and maintaining optical properties over time.

Implementation Method 1

a third layer containing a perovskite oxide having an electrooptic effect

Methodology Applied

Scientific EffectElectrooptic effect: Electro-Optic Effects

Data Source

PatentUS11709384B2Multilayer film, optical device, photonic integrated circuit device, and optical transceiver

Publication Date: 2023.07.25

AI summary

A multilayer film includes a single-crystal silicon layer, a first layer containing Zr, a second layer containing ZrO2, and a third layer containing a perovskite oxide having an electrooptic effect. The first layer, the second layer, and the third layer are provided in this order above the single-crystal silicon layer, and the multilayer film is transparent to a wavelength to be used.