Radiation-Emitting Device With an Angular-Selective Dielectric Mirror
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Solution Overview
Problem
Existing radiation-emitting devices, particularly for projection applications, face challenges in achieving high luminance and efficient conversion of primary radiation into secondary radiation, leading to scattered light and reduced imaging quality.
Innovation Solution
A radiation-emitting device comprising a semiconductor body with an active region, a conversion element, and a dielectric mirror that selectively transmits and reflects radiation within specific angular ranges, optimizing the emission characteristic to enhance luminance and reduce scattered light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional radiation-emitting device uses a conversion element to convert primary radiation into secondary radiation, then the luminance is improved, but scattered light increases and imaging quality deteriorates
Solution Approach 1:
The dielectric mirror is designed with spatially varying properties: it has a first angle range where it is transmissive and a second angle range where it is reflective. This local differentiation of optical properties allows the mirror to selectively manage different radiation angles, transmitting useful secondary radiation while reflecting scattered radiation away from the imaging path, thereby resolving the contradiction between luminance and imaging quality
Solution Approach 2:
The invention changes the parameter of angular selectivity for the dielectric mirror. By designing the mirror to have angle-dependent transmission and reflection characteristics, the system can differentiate between useful radiation (within the first angle range) and scattered radiation (within the second angle range), thus improving imaging quality while maintaining high luminance
2Use of energy by moving object
If the conversion element converts all primary radiation into secondary radiation, then the energy efficiency is improved, but heat generation increases
Solution Approach 1:
The dielectric mirror extracts harmful scattered radiation from the optical path by reflecting it away. This separation allows the system to maintain efficient energy conversion while removing the portion of radiation that would otherwise contribute to heat generation without providing useful imaging function, thus resolving the contradiction between energy efficiency and heat management
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 device achieves improved luminance and imaging quality by efficiently converting primary radiation into secondary radiation, minimizing wasted radiation and reducing heat absorption, making it suitable for projection applications.
Implementation Method 1
The conversion element (2) is configured for converting the first radiation into second radiation
Implementation Method 2
The dielectric mirror (3) is transmissive to second radiation that is incident at angles of incidence in a first angle range and is reflective for second radiation that is incident at angles of incidence in a second angle range
Data Source
AI summary
A radiation-emitting device includes an optoelectronic component for emitting first electromagnetic radiation. The radiation-emitting device also includes a conversion element having an entrance surface and an exit surface. The radiation-emitting device further includes a dielectric mirror on the exit surface. The radiation-emitting device is configured such that first radiation emitted by the component during operation enters the conversion element via the entrance surface. The conversion element is configured for converting the first radiation into second electromagnetic radiation, which subsequently exits the conversion element via the exit surface. The dielectric mirror is transmissive to second radiation that is incident at angles of incidence in a predefined first angle range, and is reflective for second radiation that is incident at angles of incidence in a predefined second angle range.