Quantum Dot Refractive Index Control via Tunneling Injection
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Solution Overview
Problem
Current refractive index changing materials, such as secondary or tertiary non-linear optical materials, achieve limited changes (less than 1%) in transparent regions, and liquid crystals lose recorded data when power is stopped, limiting their application in optical computers and displays.
Innovation Solution
A refractive index changing apparatus and method utilizing quantum dots with discrete energy levels, surrounded by a dielectric barrier structure, where electrons are injected or prevented from being injected using a tunneling effect, allowing for significant refractive index changes exceeding 1% and stable data retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If secondary or tertiary non-linear optical materials are used to change refractive index, then the material remains transparent, but the refractive index change is limited to less than 1%
Solution Approach 1:
The patent changes the physical state of the optical material from continuous (non-linear optical materials) to discrete (quantum dots with discrete energy levels). By controlling electron injection into specific quantum states and utilizing tunneling effects through barrier structures, the system achieves refractive index changes exceeding 1% while maintaining transparency, resolving the contradiction between refractive index change magnitude and transparency maintenance.
2Quantity of substance
If liquid crystal is used to achieve refractive index change of about 10%, then the refractive index change is significant, but the recorded data disappears when power supply is stopped
Solution Approach 1:
The patent replaces the liquid crystal system (which requires continuous power supply to maintain state) with a quantum dot system utilizing quantum mechanical tunneling effects. Electrons are injected into quantum dots through tunneling when energy levels align, creating stable refractive index changes that persist without power supply, thus achieving both significant refractive index change and data retention stability.
Solution Approach 2:
The patent performs preliminary electron injection into quantum dots before power supply is needed for data retrieval. By pre-injecting electrons into quantum dots at specific energy levels, the system creates stable refractive index patterns that are retained indefinitely, allowing data to be written once and read multiple times without power consumption for maintenance.
3Quantity of substance
If electron injection is controlled by changing energy level of injection unit, then refractive index change is achieved, but the system complexity increases
Solution Approach 1:
The patent utilizes periodic alignment of energy levels between the injection unit and quantum dots to control electron injection. By periodically adjusting the energy level of the injection unit to match quantum dot energy levels, electrons are injected in a controlled manner during specific time windows, achieving refractive index change without requiring continuously complex control systems.
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 apparatus achieves a refractive index change of more than 1% in transparent regions and allows for recording and stable retention of refractive index changes, surpassing the limitations of existing technologies by maintaining the refractive index change even when power is stopped.
Implementation Method 1
an injection unit configured to inject an electron into a position of the ground level in each of the quantum dots via the barrier structure unit, utilizing a tunneling effect, or to prevent injection of an electron into the position, injecting the electron or preventing injection of the electron controlled by changing an energy level of the injection unit
Implementation Method 2
a first light source which emits, to the quantum dots, a first light beam having first energy for exciting electrons from the ground level to the excited level
Data Source
AI summary
Refractive index changing apparatus includes quantum dots each having discrete energy levels including ground level and excited level, the excited level being higher than the ground level even if energy due to ambient temperature is provided on the quantum dots, barrier structure unit formed of dielectric which surrounds the quantum dots, injection unit configured to inject an electron into position of the ground level in each quantum dot via the barrier structure unit, utilizing tunneling effect, or to prevent injection of an electron into the position, injecting the electron or preventing injection of the electron controlled by changing an energy level of the injection unit, source which emits, to the quantum dots, first light beam having first energy for exciting electrons from the ground level to the excited level, and source which emits, to the quantum dots, second light beam having second energy different from the first energy.