Fiber Optic Bundle Vibration for Laser Speckle Reduction
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Solution Overview
Problem
The speckle effect caused by coherent light sources, such as lasers, results in grainy images during minimally invasive surgical and endoscopic procedures, which conventional light sources do not exhibit due to their low coherence, making it undesirable for these applications.
Innovation Solution
A vibrating mechanism is attached to a fiber optic bundle carrying the coherent light, introducing rapid changes in the light path geometry to reduce the coherence of the laser light, effectively eliminating the observable speckle pattern by oscillating the fiber optic bundle at a frequency of approximately 20Hz or higher.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a coherent light source (laser) is used for illumination, then power efficiency and controlled light generation are improved, but a speckle pattern appears making the image grainy
Solution Approach 1:
The patent applies mechanical vibration by oscillating a diffuser element at high frequency (e.g., ultrasonic frequencies) to rapidly change the scattering properties of the light path. This vibration causes the speckle pattern to fluctuate rapidly in space and time, and when captured by the imaging sensor, the rapid fluctuations average out to reduce the visible speckle graininess while maintaining the benefits of coherent light illumination
2Object-affected harmful factors
If a moving diffuser is placed in the light path to reduce speckle, then the speckle pattern is reduced, but device complexity increases
Solution Approach 1:
The patent employs a thin film diffuser that can be oscillated at high frequencies. This thin film structure achieves speckle reduction with minimal added complexity compared to traditional moving diffusers, as the thin film requires less mechanical structure to support and actuate, thereby reducing overall device complexity while maintaining effective speckle mitigation
Solution Approach 2:
By using ultrasonic or high-frequency vibration of the diffuser, the system achieves speckle reduction without requiring large-scale mechanical movements. This high-frequency oscillation can be implemented with compact piezoelectric actuators or similar devices, minimizing the mechanical complexity compared to slower, larger-scale moving diffuser systems
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 substantially eliminates the speckle pattern, providing a clearer image for human observation and image capture, while maintaining the benefits of laser light sources like power efficiency and controlled light generation.
Implementation Method 1
A vibrating mechanism is attached to a fiber optic bundle carrying the coherent light, introducing rapid changes in the light path geometry to reduce the coherence of the laser light, effectively eliminating the observable speckle pattern by oscillating the fiber optic bundle at a frequency of approximately 20Hz or higher.
Implementation Method 2
The speckle effect refers to a pattern in which there is a random distribution of varying light intensity levels and may occur with coherent light sources. It is caused by the interference of many waves of the same frequency, but different phases and amplitudes, combining and resulting is a wave whose amplitude and intensity varies randomly.
Data Source
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AI summary
The disclosure extends to methods, devices, and systems for removing speckle from a coherent light source, such as laser light. The methods, devices, and systems help eliminate or reduce speckle introduced from a coherent light source, such as laser light, by utilizing the teachings and principles of the disclosure. With increasing use of laser technology in various applications, the occurrence of speckle effect has increased. The speckle effect refers to a pattern in which there is a random distribution of varying light intensity levels and may occur with coherent light sources.