Dual-Emission Light Source Using Frequency Doubling for Safe UV-C Disinfection
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Solution Overview
Problem
Current UV disinfection methods, such as UV LEDs and mercury lamps, are inefficient for wavelengths shorter than 260 nm, require evacuation of spaces for effective disinfection, and lack reliable safety features to prevent human exposure to UV radiation, while existing UV lasers with shorter wavelengths are expensive and not designed for human presence environments.
Innovation Solution
A light generating device combining a laser light source with a frequency doubling element and a luminescent element to produce both UV and visible light, where the laser light source emits wavelengths between 380-420 nm for safe disinfection, and the frequency doubling element converts a portion of this light into UV-C range, ensuring user safety through visible emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If UV LEDs are used for disinfection, then the device can operate without evacuation, but the performance at wavelengths shorter than 260 nm is very poor
Solution Approach 1:
The patent changes the wavelength parameter by using a laser light source that emits at 405 nm (visible range) and converts it to 202.5 nm UV-C radiation through frequency doubling, achieving wavelengths shorter than 260 nm that UV LEDs cannot effectively produce while maintaining operational safety through visible light emission
2Quantity of substance
If mercury lamps are used for UV treatment, then broad UV coverage is achieved, but the light cannot be efficiently focused into a small area or collimated beam
Solution Approach 1:
The patent segments the UV radiation generation by using a laser light source that produces a highly directional, coherent beam at 405 nm, which can be efficiently focused and collimated, then converts only the necessary portion to UV-C through frequency doubling, achieving both focusability and adequate UV coverage
Solution Approach 2:
The patent changes the emission characteristics by using a laser diode that emits a narrow, collimated beam at 405 nm with high spatial coherence, which can be precisely focused into small areas, unlike the broad omnidirectional emission of mercury lamps
3Illumination intensity
If existing UV lasers with wavelengths shorter than 280 nm are used, then high brightness and collimated beam are achieved, but the components are very expensive and not designed for human presence environments
Solution Approach 1:
The patent segments the laser emission into two portions: one portion (first portion) is frequency-doubled to generate UV-C radiation, while another portion (second portion) is converted to visible light through a luminescent element, providing both disinfection and safety indication functions
Solution Approach 2:
The patent introduces a luminescent element as an intermediary that converts a portion of the 405 nm laser light into visible light wavelengths, serving as both a safety indicator for human presence and a cost-effective alternative to expensive UV laser diodes
4Productivity
If UV light sources are used for disinfection in environments with human presence, then disinfection effectiveness is improved, but there is a risk for unintentional irradiation by UV light
Solution Approach 1:
The patent uses color changes as a safety mechanism by converting a portion of the 405 nm laser light into visible light through a luminescent element, providing a visible indicator that warns of potential UV radiation presence, thereby reducing unintentional human exposure while maintaining disinfection effectiveness
Solution Approach 2:
The patent segments the laser output to emit both UV-C radiation (first portion) for disinfection and visible light (second portion converted through luminescent element) for safety indication, allowing simultaneous disinfection and human presence safety
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 provides high-brightness visible light with effective germicidal UV-C radiation, enhancing safety and disinfection efficiency in environments with human presence by simultaneously emitting visible and UV light, suitable for healthcare facilities.
Implementation Method 1
The first frequency doubling element is arranged for converting at least a portion of the first portion of the first laser light emitted by the first laser light source into a first frequency doubled light having a third peak wavelength λ3 selected from a spectral wavelength range from 190 to 245 nm (second harmonic generation)
Implementation Method 2
The first luminescent element comprises a first luminescent material configured to convert at least a portion of the second portion of the first laser light into a first converted light having a fourth peak wavelength λ4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range
Data Source
AI summary
The present invention relates to a light generating device (1) configured to generate device light (9), the light generating device comprising a first laser light source (2), a first frequency doubling element (4), a first luminescent element (6), and a light exit window (7). The first laser light source (2) is arranged for generating first laser light (3) being at least one of violet laser light having a first peak wavelength λ1 selected from a spectral wavelength range from 380 to 420 nm and blue laser light having a second peak wavelength λ2 selected from a spectral wavelength range from 420 to 490 nm. The first laser light (3) comprises at least a first portion (3′) and a second portion (3″). The first frequency doubling element (4) is arranged for converting at least a portion of the first portion (3′) of the first laser light (3) emitted by the first laser light source (2) into a first frequency doubled light (5) having a third peak wavelength λ3 selected from a spectral wavelength range from 190 to 245 nm. The first luminescent element (6) comprises a first luminescent material configured to convert at least a portion of the second portion (3″) of the first laser light (3) into a first converted light (8) having a fourth peak wavelength λ4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range. The light exit window (7) is arranged to release the device light (9) comprising the first frequency doubled light (5) and the first converted light (8).