On-Chip UV Power Readout via Adjacent Mesa Detection
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Solution Overview
Problem
Traditional deep ultraviolet (DUV) light sources, such as AlGaN-based LEDs, lack direct visual readout of UV output power, making it difficult to ensure sufficient disinfection dosage and maintain constant output power over their lifespan, as UV emissions are not perceptible to the human eye and are subject to power decay.
Innovation Solution
A light-emitting device with on-chip optical power readout, featuring a light emitting mesa and a light detecting mesa formed adjacent to each other on the same substrate, sharing the same epitaxial structure but electrically isolated by an insulation region, allowing for real-time monitoring of UV emission power and maintaining constant output power through feedback control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate photodetector is used to measure light source power, then optical power monitoring is achieved, but device complexity increases and integration is reduced
Solution Approach 1:
The patent merges the light-emitting function and light-detecting function into a single integrated device. The light-emitting mesa and light-detecting mesa are formed on the same substrate with identical epitaxial structures, creating a monolithic integration that eliminates the need for separate photodetector components while achieving real-time optical power monitoring
2Reliability
If UV light sources are used for disinfection, then germicidal effect is achieved, but visual readout of output power becomes impossible
Solution Approach 1:
The patent uses the light-detecting mesa as an intermediary component that converts UV light emissions into measurable electrical signals. The detector mesa receives UV emissions from the light-emitting mesa and generates corresponding electrical signals that can be read out, providing indirect visual measurement of UV output power without compromising the germicidal effectiveness
3Adaptability or versatility
If light emitting mesa and light detecting mesa share same substrate, then integration is improved, but electrical isolation becomes challenging
Solution Approach 1:
The patent segments the chip into distinct light-emitting mesa and light-detecting mesa regions that are electrically isolated from each other. The insulation region creates clear electrical boundaries between the two functional areas, allowing independent electrical connections while maintaining physical integration on the same substrate
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
Enables reliable real-time monitoring and maintenance of UV output power, ensuring effective disinfection and prolonged device performance by integrating UV emission detection directly on the chip, enhancing the efficiency and reliability of UV light sources.
Implementation Method 1
The light detecting mesa receives part of the emissions given by the light-emitting mesa and responds with outputting an electrical signal
Data Source
AI summary
A light emitting device with on-chip optical power readout includes a light emitting mesa and a light detecting mesa formed adjacent to each other on the same substrate of a chip, and a portion of the light emitted from the light emitting mesa is transmitted to the light detecting mesa at least through the substrate. The light emitting mesa and the light detecting mesa have exactly the same epitaxial structure and can be electrically isolated from each other by an insulation layer, or an airgap formed therebetween, or by ion implantation. The light emitting mesa and the light detecting mesa can also share an n-type structure and a common n-electrode while having their own p-electrode, respectively.