GaN Laser Diode and Phosphor Integrated White Light Source
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Solution Overview
Problem
Conventional light sources, such as incandescent bulbs and LEDs, face issues like high energy dissipation, thermal failure, broad spectrum emission, and lack of directionality, which limit their efficiency and application in specific lighting needs.
Innovation Solution
A compact, high-brightness white light source is created by integrating gallium and nitrogen-based laser diodes with phosphor materials, allowing for efficient energy conversion and directional light emission, enabling a cost-effective and highly efficient white light solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional light bulbs are used, then they provide general illumination, but they dissipate more than 90% of energy as thermal energy
Solution Approach 1:
The invention transitions from thermal radiation (incandescent) to electroluminescence (LED), fundamentally changing the energy conversion mechanism. This parameter change in the physical process eliminates the 90%+ thermal energy waste inherent in filament-based lighting.
Solution Approach 2:
The patent replaces the mechanical/thermal system of incandescent bulbs with an electrical/optical system using LED technology. This substitution eliminates the need for thermal conversion, directly converting electrical energy to light energy with minimal heat loss.
2Illumination intensity
If conventional light bulbs are used, then they emit light over a broad spectrum, but much of the light is not perceived by the human eye
Solution Approach 1:
The invention uses LED chips with specific bandgap energies to emit light in the visible spectrum range (380-780nm). By tailoring the semiconductor material composition, the emission spectrum is localized to wavelengths perceptible by the human eye, eliminating energy waste in non-visible regions.
Solution Approach 2:
The patent changes the emission spectrum parameters by selecting appropriate LED chip materials and wavelengths. This ensures that the majority of emitted photons fall within the human visual response curve, maximizing perceived illumination efficiency.
3Ease of operation
If conventional light bulbs are used, then they emit in all directions, but this is undesirable for applications requiring strong directionality
Solution Approach 1:
The invention exploits the inherently asymmetric emission pattern of LED chips. Unlike omnidirectional incandescent bulbs, LEDs naturally emit light in a directional pattern that can be further shaped using optical elements, enabling precise control over illumination direction and focus.
Solution Approach 2:
The patent introduces optical intermediaries such as lenses, reflectors, and light guides between the LED source and the target area. These intermediaries shape and direct the light output, transforming the LED's natural emission pattern into highly directional beams suitable for projection and focused illumination applications.
4Reliability
If conventional light bulbs are used, then they have simple structure, but they routinely fail due to thermal expansion and contraction
Solution Approach 1:
The invention replaces the thermal-based incandescent system with an electrical LED system that operates at much lower temperatures. This substitution eliminates the thermal expansion and contraction cycles that cause filament failure, dramatically improving reliability and lifetime.
Solution Approach 2:
The patent changes the operating temperature parameter from thousands of degrees (incandescent) to much lower levels (LED). This parameter change eliminates the thermal stress that causes conventional bulb failure, resulting in products with lifetimes measured in tens of thousands of hours rather than hundreds.
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 integrated laser diode and phosphor system provides a highly efficient, directional, and cost-effective white light source with improved brightness and longevity, suitable for various applications including lighting, displays, and specialized uses.
Implementation Method 1
The laser device is a gallium and nitrogen based laser diode that emits laser light when activated
Implementation Method 2
The phosphor material has a conversion efficiency that is greater than 200 lumens per optical watt of laser light absorbed and greater than 70% of the emitted light is in a wavelength regime from 500 nanometers to 700 nanometers
Implementation Method 3
The emitted light from the phosphor material is mixed with the blue emission from the laser diode to produce white light
Data Source
AI summary
The present invention provides a device and method for an integrated white colored electromagnetic radiation source using a combination of laser diode excitation sources based on gallium and nitrogen containing materials and light emitting source based on phosphor materials. In this invention a violet, blue, or other wavelength laser diode source based on gallium and nitrogen materials is closely integrated with phosphor materials, such as yellow phosphors, to form a compact, high-brightness, and highly-efficient, white light source.