Lanthanide White Light Source for High-CRI Thermal Stability
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Solution Overview
Problem
Current light generating systems face challenges in achieving high brightness and color rendering index (CRI) while maintaining thermal stability, especially at high-power densities, due to limitations in heat management and the need for additional red and green laser diodes.
Innovation Solution
A light generating system comprising a first and second laser with lanthanide-based luminescent materials, configured to convert light into different spectral ranges, eliminating the need for additional red and green laser diodes by using a single pump laser to produce white light with a CRI ≥80 and a correlated color temperature (CCT) between 2000-6500 K.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pump laser with lanthanide-based luminescent materials is used to generate white light, then the device complexity is reduced and thermal management is simplified, but achieving high brightness and high CRI simultaneously becomes more challenging
Solution Approach 1:
The patent segments the white light generation into multiple laser wavelengths (red, green, blue) that are combined to form white light. Each laser operates at a specific wavelength range, and their superposition creates the full-spectrum white light with high CRI, while maintaining a simplified single-pump architecture.
Solution Approach 2:
The patent utilizes parameter changes in lanthanide-based luminescent materials to achieve different emission wavelengths. By selecting appropriate lanthanide ions (e.g., Er3+, Tm3+, Ho3+) and adjusting their concentrations and host materials, the system generates multiple discrete wavelengths from a single pump source, resolving the contradiction between simplicity and spectral quality.
2Illumination intensity
If additional red and green laser diodes are added to improve CRI and brightness, then the illumination quality improves, but the device complexity and thermal management burden increase
Solution Approach 1:
The patent makes a single pump laser perform multiple functions by using lanthanide-based luminescent materials that can emit multiple wavelengths simultaneously. The pump laser excites different lanthanide ions or the same ion at different transitions, generating red, green, and blue components all from one source, thereby eliminating the need for multiple separate laser diodes.
Solution Approach 2:
The patent merges the functions of multiple laser diodes (red, green, blue) into a single pump laser system. By combining the luminescent materials and optical paths, the system achieves the spectral output of multiple lasers while maintaining a unified, simplified architecture with reduced thermal management requirements.
3Illumination intensity
If high-power densities are used to achieve high brightness, then the illumination intensity improves, but thermal stability deteriorates due to heat management limitations
Solution Approach 1:
The patent employs periodic or pulsed laser operation to manage thermal load. By operating the pump laser in pulsed modes or with duty cycles, the system achieves high peak brightness while allowing thermal dissipation between pulses, maintaining thermal stability even at high average power levels.
Solution Approach 2:
The patent introduces lanthanide-based luminescent materials as intermediaries that convert pump laser energy into multiple wavelengths with efficient photon conversion. These materials have high thermal conductivity and stable crystal structures that act as thermal buffers, converting concentrated pump energy into distributed multi-wavelength emission while maintaining thermal stability.
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 system achieves high intensity white light with improved CRI and CCT, simplifying architecture and reducing thermal management issues, while maintaining thermal stability and eliminating the need for additional laser diodes.
Implementation Method 1
the first laser comprises a first lanthanide based luminescent material configured to convert at least part of the first device light having the first device centroid wavelength (λcd,1) into first luminescent material light
Implementation Method 2
the light generating system is configured to provide system light comprising the first laser light and the second laser light, and wherein in the first operational mode the system light is white light
Data Source
AI summary
The invention provides a light generating system (1000) comprising (a) first light generating device (110), (b) a first laser (2100), and (c) a second laser (2200), wherein:—the first light generating device (110) is configured to generate first device light (111) having a first device centroid wavelength (λcd,1), wherein the first light generating device (110) comprises one or more of a solid state material laser and a super luminescent diode; —the first laser (2100) comprises a first lanthanide based luminescent material (2110) configured to convert at least part of the first device light (111) having the first device centroid wavelength (λcd,1) into first luminescent material light (2111), wherein the first laser (2100) is configured downstream of the first light generating device (110) and is configured to provide first laser light (2101) comprising at least part of the first luminescent material light (2111), wherein the first laser light (2101) has a first centroid laser wavelength (λcl,1) in the visible; —the second laser (2200) comprises a second lanthanide based luminescent material (2210) configured to convert at least part of the first device light (111) having the first device centroid wavelength (λcd,1) into second luminescent material light (2211), wherein the second laser (2200) is configured downstream of the first light generating device (110) and is configured to provide second laser light (2201) comprising at least part of the second luminescent material light (2211), wherein the second laser light (2201) has a second centroid laser wavelength (λcl,2) in the visible, wherein |λcl,2−λcl,1|≥25 nm; —the first centroid laser wavelength (λcl,1) and the second centroid laser wavelength (λcl,2) are selected from different wavelength ranges from C the group of (i) 495-570 nm, (ii) 570-590 nm, (iii) 590-620 nm, and (iv) 620-780 nm, and—in a first operational mode of the light generating system (1000) the light generating system (1000) is configured to provide system light (1001) comprising the first laser light (2101) and the second laser light (2201), and wherein in the first operational mode the system light (1001) is white light.