Waveguide Fabry-Pérot Resonator for Stable Spin-Entangled Photon Emission

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing spin-entangled photon emission devices face challenges in achieving high efficiency and mechanical stability due to the trade-off between Purcell factor and mechanical instability caused by vibrations in Fabry-Pérot cavities.

Innovation Solution

A spin-entangled photon emission device with a Fabry-Pérot resonator integrated with a solid-state optical waveguide on a substrate, where the diamond membrane forms one mirror, and the optical waveguide is strained using a controllable pressure exercising layer, such as a Piezo-electric layer, to tune the resonance wavelength and maintain mechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a Fabry-Pérot cavity with high finesse is used to increase the Purcell factor and entangled photon emission rate, then the emission efficiency is improved, but mechanical instability due to vibrations increases

Engineering Contradiction:
Improveentangled photon emission rateVSAvoidmechanical stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent merges the Fabry-Pérot resonator with a solid-state optical waveguide by integrating the diamond membrane containing the photon source directly into the waveguide structure. This integration eliminates the need for separate mechanical cavity components that are susceptible to vibrations, while maintaining the optical resonance functionality for enhancing photon emission.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the traditional mechanical Fabry-Pérot cavity structure with an optical waveguide-based resonator. The resonance is achieved through optical confinement in the waveguide rather than mechanical reflection between separate mirrors, eliminating mechanical instability while preserving the Purcell enhancement effect.

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

2Reliability

If the cavity finesse is lowered to reduce losses due to mechanical instability, then mechanical stability is improved, but the Purcell factor and emission efficiency decrease

Engineering Contradiction:
Improvemechanical stabilityVSAvoidentangled photon emission rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the mechanical cavity system with an integrated optical waveguide resonator, eliminating the trade-off between finesse and mechanical stability. The waveguide structure provides inherent mechanical stability while allowing high optical confinement and resonance quality through its geometric and material properties.

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

Solution Approach 2:

The patent uses a composite structure combining diamond membrane with the optical waveguide material. This composite integration allows the system to benefit from both the mechanical stability of the solid-state waveguide and the optical properties of diamond for high-quality resonance and photon emission.

Inventive Principle:
Principle #40Composite materials

3Productivity

If a diamond membrane with defect center is placed into a Fabry-Pérot cavity to increase emission rate, then the Purcell factor is improved, but the device complexity increases

Engineering Contradiction:
Improvephoton emission rateVSAvoidcavity structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines the diamond membrane containing the defect center with the optical waveguide into a single integrated structure. The diamond membrane serves dual purposes as both the photon source host and part of the resonator structure, eliminating the need for separate cavity components and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The diamond membrane in the patent serves multiple functions: it hosts the defect center for photon generation, acts as part of the optical waveguide structure, and provides the resonant cavity functionality. This multi-functionality reduces the number of separate components needed and simplifies the overall device architecture.

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

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 enhances the entangled photon emission rate by concentrating the electromagnetic field and reducing mechanical instability, allowing for a higher Purcell factor and narrower resonance bandwidth, thereby increasing the production rate of entangled states.

Implementation Method 1

placing a diamond membrane with the defect center into a Fabry-Pérot cavity increases the emission rate of the defect center by a factor (known as the Purcell factor), which can be translated into the increase of the efficiency of coherence high photon emission from the defect center

Methodology Applied
Scientific EffectPurcell effect:

Implementation Method 2

The resonance frequency of the cavity mode is tuned by moving the top mirror vertically relative to the bottom mirror using Piezoelectric nano-positioners

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

the Fabry-Pérot resonator comprises a solid state optical waveguide integrated on a substrate... concentrating the electromagnetic field

Methodology Applied
Scientific EffectOptical waveguide confinement: Waveguide (optics)

Data Source

PatentEP4073959B1Spin-entangled photon emission device
Publication Date: 2024.02.07 NEDERLANDSE ORG VOOR TOEGEPAST NATUURWETENSCHAPPELIJK ONDERZOEK TNO
  • EP4073959B1 patent drawingFigure 1~2
  • EP4073959B1 patent drawingFigure 3
  • EP4073959B1 patent drawingFigure 4

AI summary

The spin-entangled photon emission device comprises a Fabry-Pérot resonator with a solid state optical waveguide integrated on a substrate. Preferably, the device is used in a configuration that makes it possible to tune the resonance wavelength of the Fabry-Pérot resonator by straining or otherwise adjusting the effective optical length of the waveguide. A diamond membrane is located in the Fabry-Pérot resonator. The diamond membrane comprises a photon-source capable of emitting a photon that is entangled with a spin state of the photon source. A first surface of the diamond membrane abuts to a first mirror of the Fabry-Pérot resonator. The optical waveguide has a first end facet bonded to a first surface of the diamond membrane. The first mirror of the Fabry-Pérot resonator is formed by a reflector on the second surface of the diamond membrane. The second mirror of the Fabry-Pérot resonator is formed by a reflector on a second end facet of the optical waveguide or inside the optical waveguide.