Colloid Diffuser for Laser Speckle Reduction
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Solution Overview
Problem
The use of coherent light sources, such as lasers, for uniform illumination is impractical due to the inherent speckle pattern caused by interference, which is difficult to eliminate with existing active solutions that require mechanical or electrical components, adding noise and complexity.
Innovation Solution
A passive diffuser using a colloid that exhibits Brownian motion is introduced, which inherently provides random motion to scatter light uniformly without the need for power or mechanical movement, effectively reducing or eliminating laser speckle patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a coherent light source (laser) is used for illumination, then the cost effectiveness and coherence of the light source is improved, but the uniformity of illumination deteriorates due to speckle patterns
Solution Approach 1:
The patent employs a vibrating diffuser that introduces dynamic motion to the light path, causing the speckle pattern to change rapidly over time. This temporal variation allows the sensor to capture multiple speckle realizations that can be averaged or processed to reduce speckle noise, thereby improving illumination uniformity while maintaining laser coherence
Solution Approach 2:
The patent introduces a temporal dimension by vibrating the diffuser, transforming a static speckle pattern into a dynamic one. This adds the time dimension to the spatial speckle pattern, enabling the system to achieve uniform illumination through temporal averaging or processing of multiple frames
2Illumination intensity
If active solutions (mechanical or electrical components) are used to eliminate speckle patterns, then the uniformity of illumination is improved, but the system complexity and noise increase
Solution Approach 1:
The vibrating diffuser is designed to exploit the natural tendency of the system to minimize potential energy. By creating an unstable equilibrium configuration, the diffuser vibrates autonomously without requiring external power or control systems, thereby reducing device complexity while still achieving speckle reduction through the introduced motion
3Illumination intensity
If active solutions (mechanical or electrical components) are used to eliminate speckle patterns, then the uniformity of illumination is improved, but the noise and power requirements increase
Solution Approach 1:
The vibrating diffuser operates passively by exploiting gravitational potential energy and mechanical instability rather than requiring external power sources. The system self-generates the necessary vibrations through its unstable equilibrium configuration, eliminating the need for motors, drivers, or power consumption while still achieving speckle reduction
Solution Approach 2:
The patent replaces active mechanical vibration systems (motors, drivers, power sources) with a passive mechanical instability mechanism. This substitution eliminates the need for electrical power and complex control systems while maintaining the beneficial effect of diffuser motion for speckle reduction
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 colloid diffuser achieves robust and cost-effective uniform illumination, eliminating speckle effects and reducing system noise, making coherent light sources suitable for applications requiring uniform illumination.
Implementation Method 1
A passive diffuser using a colloid that exhibits Brownian motion is introduced, which inherently provides random motion to scatter light uniformly without the need for power or mechanical movement
Implementation Method 2
effectively reducing or eliminating laser speckle patterns
Data Source
AI summary
Laser speckle reduction using a passive diffuser. A diffuser for reducing laser speckle is disclosed comprising a diffuser having a colloid configured for placement in a light path of a coherent light source. The colloid exhibits Brownian motion. The diffuser can be formed of transparent plates containing the colloid. In a system for illumination, a coherent source of light outputting a light beam along a light path is provided; and a diffuser for reducing laser speckle effects is placed in the light path, the diffuser comprising a colloid disposed in a container that is transparent to the light beam output by the coherent source. A method includes illuminating a photosensitive sensor, comprising transmitting a coherent light from a light source through a diffuser comprising a colloid and directing the light from the diffuser onto the photosensitive sensor. Additional embodiments are disclosed.