Fluorescence Light Source Wavelength Conversion Member T/R Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fluorescence light source devices face inefficiencies in excitation light incidence and fluorescence intensity due to scattering by pores or microparticles in the wavelength conversion member, leading to reduced utilization of excitation light and fluorescence emission.
Innovation Solution
A fluorescence light source device with a wavelength conversion member featuring a periodic structure of conical or truncated projections and micro-scatterers with a refractive index greater than 1.0, optimizing the light transmission and reflection ratio (T/R) between 1 and 20, to enhance excitation light incidence and fluorescence extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If pores or scattering microparticles are contained in the wavelength conversion member, then excitation light can be scattered to increase light distribution, but excitation light is scattered out without conversion reducing fluorescence intensity
Solution Approach 1:
The invention changes the refractive index parameter of the wavelength conversion member by adding micro-scatterers with refractive index ≥1.0, transforming it from a simple scattering medium to a controlled light management structure. This parameter change enables the member to trap excitation light through internal reflection while maintaining fluorescence generation, resolving the contradiction between light distribution and light utilization.
Solution Approach 2:
The invention creates a composite wavelength conversion member combining phosphor material with micro-scatterers (having refractive index ≥1.0). This composite structure enables dual functionality: the phosphor converts excitation light to fluorescence, while the micro-scatterers trap and redistribute excitation light within the member, preventing energy loss and enhancing overall fluorescence intensity.
2Productivity
If a periodic structure with conical projections is formed on the front surface, then excitation light incidence efficiency is improved, but device complexity increases
Solution Approach 1:
The invention applies curved conical projections with specific aspect ratios (0.05-0.5) to the front surface periodic structure. These curved geometries optimize light coupling by gradually transitioning the refractive index interface, reducing reflection losses and enhancing excitation light incidence efficiency compared to flat or sharp-edged structures.
Solution Approach 2:
The invention optimizes the periodic structure parameters including projection pitch (0.5-5 μm), height (1-10 μm), and aspect ratio (0.05-0.5). By carefully controlling these parameters, the structure achieves optimal light trapping and incidence efficiency while maintaining manufacturability, balancing performance improvement with device complexity.
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 high excitation light incidence efficiency and effective fluorescence generation and emission, resulting in improved luminous efficiency and reduced light confinement within the wavelength conversion member.
Implementation Method 1
the excitation light receiving surface includes a periodic structure having a periodic array of conical or truncated projections with an aspect ratio, which is a ratio of the height of the projection to the pitch in the periodic structure, of not lower than 0.2
Implementation Method 2
the wavelength conversion member contains a micro-scatterer with a refractive index of not lower than 1.0 for scattering the excitation laser light and fluorescence emitted from the phosphor
Implementation Method 3
a wavelength conversion member for emitting fluorescence by excitation laser light
Data Source
AI summary
A fluorescence light source device includes a wavelength conversion member that emits fluorescence by excitation laser light. The wavelength conversion member has an excitation laser light receiving surface including a periodic structure having a periodic array of conical or truncated projections with an aspect ratio, which is a ratio of the height of the projection to the pitch in the periodic structure, of not lower than 0.2. The wavelength conversion member is formed from a phosphor composed of a polycrystal and contains a micro-scatterer with a refractive index of not lower than 1.0 for scattering the excitation laser light and fluorescence emitted from the phosphor. A ratio (T/R) between a light transmission percentage T [%] in the wavelength conversion member and a light reflection percentage R [%] in the wavelength conversion member is 1 to 20.