Illumination Device Using Light Scattering Material to Reduce Laser Coherence
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Solution Overview
Problem
Illumination devices that use laser light to excite fluorescent substances pose a risk to the human eye due to potential leakage of high-coherence laser light, which can occur from misalignment of optical elements, displacement of the fluorescent substance, or incomplete absorption of laser light by the substance.
Innovation Solution
Incorporating a light scattering material on and around the optical axis of the laser light to scatter and reduce the coherence of the laser light, ensuring it is transmitted through the scattering material even if the optical axis or fluorescent substance is displaced, and placing the light scattering material in close contact with the fluorescent substance to further reduce coherence before excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If laser light is used to excite fluorescent substance, then high luminance and illuminance are achieved, but high-coherence laser light may leak causing eye safety risk
Solution Approach 1:
A light scattering member is introduced as an intermediary component between the laser light source and the fluorescent substance. This member scatters the laser light to reduce its coherence while still allowing it to excite the fluorescent substance, thereby eliminating the eye safety risk without reducing the illumination intensity.
Solution Approach 2:
The harmful high-coherence property of the laser light is extracted and removed by the light scattering member, while the useful excitation function is preserved. The scattering member selectively removes the coherence attribute that causes eye damage while maintaining the light's ability to excite the fluorescent substance.
2Object-affected harmful factors
If light scattering member is placed in optical path, then laser light coherence is reduced improving safety, but light transmission efficiency may decrease
Solution Approach 1:
The light scattering member is designed with specific local properties - it scatters light in a controlled manner to reduce coherence while maintaining sufficient transmission. The scattering particles or structures are positioned and sized to achieve the desired balance between coherence reduction and energy transmission.
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 solution effectively prevents high-coherence laser light from leaking outside, ensuring eye safety while maintaining high luminance and illuminance, and allows for reliable operation even with misalignment or displacement of optical components.
Implementation Method 1
liquid or swollen gel including a dynamic light scattering system (region including light scattering system) is placed in an optical path of light emitted from a semiconductor laser element, to thereby convert the light having high coherence to incoherent light, which is not harmful to the human, by dynamic multiple light scattering (Brownian motion)
Implementation Method 2
a light scattering member including light scattering particles for scattering laser light is placed in an optical path of light emitted from a semiconductor laser element, so that the light emitted from the semiconductor laser element is scattered while passing through the light scattering member
Implementation Method 3
Illumination device for exciting a fluorescent substance by irradiating the fluorescent substance with laser light from a laser irradiation device to emit visible light
Data Source
AI summary
Provided is an illumination device capable of reducing coherence of laser light emitted from a laser irradiation device to ensure safety to the eye at low cost. In the illumination device for exciting a fluorescent substance by irradiating the fluorescent substance with the laser light from the laser irradiation device to emit visible light for use as illumination light, a light scattering material is placed on and around an optical axis of the laser light.