Phosphor-Converted Superluminescent Diode for Tunable Speckle-Free Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light generating devices lack high intensity and tunable spectral power distribution, with narrow emission bandwidths unsuitable for display or projector applications, and exhibit speckle issues common in laser-based solutions.
Innovation Solution
A light generating system comprising a superluminescent diode and a luminescent material, controlled by a control system to achieve tunable spectral power distribution and reduced speckle, with the luminescent material converting light to broader wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If laser-based solutions are used to achieve high intensity light, then brightness is improved, but speckle issues occur
Solution Approach 1:
A phosphor conversion layer is introduced as an intermediary between the blue laser source and the target. This layer converts the coherent blue light into incoherent yellow-green light, eliminating speckle while maintaining high brightness through efficient photoluminescence conversion.
Solution Approach 2:
The patent changes the coherence parameter of the light by using phosphor conversion. The blue laser light (coherent) is transformed into yellow-green light (incoherent) through photoluminescence, fundamentally altering the coherence parameter to eliminate speckle while preserving intensity.
2Object-generated harmful factors
If conventional LEDs are used to reduce speckle, then speckle is reduced, but intensity is insufficient
Solution Approach 1:
The phosphor conversion layer acts as an intermediary that enables conventional LED-like incoherent light output while maintaining laser-level brightness. The blue laser excites the phosphor material, which then emits incoherent light with high intensity that would be difficult to achieve with conventional LEDs alone.
3Illumination intensity
If a single superluminescent diode is used to achieve high intensity, then brightness is improved, but emission bandwidth is too narrow for display applications
Solution Approach 1:
The patent segments the emission spectrum by using multiple superluminescent diodes with different peak wavelengths (blue, cyan, green) and combining them with phosphor conversion. This segmentation approach allows each diode to operate at its optimal intensity while the combination provides broad spectral coverage suitable for display applications.
Solution Approach 2:
The system uses composite phosphor materials with different emission characteristics to convert the light from multiple superluminescent diodes. The composite phosphor approach enables broad spectral output by combining the emission properties of different phosphor materials, achieving both high intensity and wide bandwidth.
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 provides high intensity light with tunable spectral power distribution and reduced speckle, suitable for display and projector applications, utilizing GaN-based or InGaN-based superluminescent diodes and luminescent materials like cerium-doped garnets for enhanced performance.
Implementation Method 1
the spontaneous emission light is amplified by stimulated emission in the active region of the device
Implementation Method 2
the first luminescent material is configured to convert at least part of the light source light into first luminescent material light
Data Source
Figure 1~2B
Figure 2C~2E
Figure 3A~3C
AI summary
The invention provides a light generating system (1000), configured to generate system light (1001), wherein the light generating system (1000) comprises a light source (10), a first luminescent material (210), and a control system (300), wherein:- the light source (10) is configured to generate light source light (11) having a tunable spectral power distribution within a first wavelength range (Λx1); wherein the light source (10) comprises a superluminescent diode;- the first luminescent material (210) is configured to convert at least part of the light source light (11) into first luminescent material light (211) having one or more wavelengths in a first luminescent material light wavelength range (Λm1);- the first luminescent material (210) is configured such that in an operational mode the system light (1001) comprises the first luminescent material light (211);- a spectral power distribution of the system light (1001) is controllable in dependence of the spectral power distribution of the light source light (11); and- the control system (300) is configured to control the spectral power distribution of the light source light (11).