Dichroic Mirror Reflects Unconverted Light in IR LED
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Broadband IR LED devices have low conversion efficiency of UV and visible light to IR radiation due to significant unconverted light escaping, resulting in unwanted UV and visible light presence in applications.
Innovation Solution
Incorporation of a dichroic mirror that reflects unconverted UV and visible light back into the wavelength converting layer for further conversion, improving the efficiency of IR light emission by separating visible and IR light using a dichroic mirror design that reflects visible light and transmits IR light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a wavelength converting layer is used to convert UV and visible light to IR radiation, then IR light emission is achieved, but unconverted UV and visible light escapes resulting in low conversion efficiency
Solution Approach 1:
A dichroic mirror is introduced as an intermediary component between the wavelength converting layer and the external environment. The mirror selectively reflects unconverted UV and visible light back into the wavelength converting layer while allowing converted IR radiation to pass through, thereby recovering energy that would otherwise be lost and improving overall conversion efficiency.
Solution Approach 2:
The dichroic mirror creates a feedback mechanism where unconverted UV and visible light that escapes the wavelength converting layer is reflected back into the layer for further conversion attempts. This feedback loop increases the probability of conversion and reduces energy loss from unconverted light escaping the device.
2Device complexity
If unconverted UV and visible light escape from the LED device, then device simplicity is maintained, but unwanted light presence in applications occurs
Solution Approach 1:
The dichroic mirror serves as an intermediary that selectively separates desired IR radiation from unwanted UV and visible light. By positioning the mirror to reflect specific wavelength ranges back into the converting layer while transmitting IR, the device eliminates harmful unconverted light without requiring complex additional filtering components.
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
Significantly enhances the conversion efficiency of UV and visible light to IR radiation, reducing unwanted light in applications and improving the overall performance of IR LED devices.
Implementation Method 1
The dichroic mirror transmits the infrared light emitted by the wavelength converting layer, reflects the light emitted by the light emitting element, and is arranged to reflect back into the wavelength converting layer light emitted by the light emitting element
Implementation Method 2
The wavelength converting layer is configured to absorb at least a portion of the light emitted by the light-emitting element and in response emit infrared light
Implementation Method 3
a wavelength converting layer overlaying the light-emitting element to convert the UV and/or visible light into IR radiation
Implementation Method 4
The dichroic mirror transmits the infrared light emitted by the wavelength converting layer
Data Source
AI summary
LED devices and methods of operating LED devices are described. An LED device includes a light-emitting element, a wavelength converting layer and a dichroic mirror. The light-emitting element is configured to emit ultra violet, visible, or ultra violet and visible light. The wavelength converting layer is configured to absorb at least a portion of the light emitted by the light-emitting element and in response emit infrared light. The dichroic mirror transmits the infrared light emitted by the wavelength converting layer, reflects the light emitted by the light emitting element, and is arranged to reflect back into the wavelength converting layer light emitted by the light emitting element, transmitted unabsorbed through the wavelength converting layer, and incident on the dichroic mirror.