Series Optical Diffusers for Speckle Reduction
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Solution Overview
Problem
Current wide-angle illumination systems face challenges in reducing noise due to speckle and achieving a larger effective extended optical source, as well as modifying the angular field-of-illumination, which existing technologies fail to address effectively.
Innovation Solution
An optical apparatus comprising a first and second optical diffuser arranged in series, where the first diffuser redirects and transforms input optical signals, and the second diffuser further redirects and transforms the output, resulting in a larger effective extended optical source and reduced speckle noise, with the option to include additional optical sources and diffusers to enhance the angular field-of-illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a single optical diffuser is used, then the device complexity is low, but the speckle noise is high and the effective source size is limited
Solution Approach 1:
The patent divides the single diffuser into multiple diffusers arranged in series (first diffuser, second diffuser, and optionally third diffuser). Each diffuser contributes to reducing speckle noise through multiple scattering events, achieving superior noise reduction compared to a single diffuser while maintaining manageable system complexity through modular arrangement.
Solution Approach 2:
The patent employs a nested configuration where multiple diffusers are positioned in series along the optical path. The first diffuser processes the input signal, the second diffuser further processes the output, and optionally a third diffuser provides additional processing. This nested arrangement allows each diffuser to build upon the work of the previous ones, achieving cumulative speckle reduction.
2Area of stationary object
If a single optical diffuser is used, then the manufacturing is simple, but the effective extended source size is limited
Solution Approach 1:
The patent segments the illumination function across multiple diffusers positioned in series. This segmentation allows the effective source size to be extended by the cumulative effect of multiple scattering events, creating a larger apparent source area without requiring a single large complex diffuser element.
Solution Approach 2:
The patent extends the effective source size by adding the spatial dimension of multiple diffusers in series. Instead of relying on a single diffuser's surface area, the system creates an extended effective source through the spatial distribution and optical path length introduced by multiple diffusers positioned at different locations along the beam path.
3Adaptability or versatility
If a single optical diffuser is used, then the angular field-of-illumination is limited, but the device structure is simple
Solution Approach 1:
The patent divides the angular illumination function across multiple diffusers in series. Each diffuser contributes to expanding the angular field-of-illumination through its scattering properties, and the cumulative effect of multiple diffusers achieves a broader angular distribution than any single diffuser could provide alone.
Solution Approach 2:
The patent modifies the angular field-of-illumination parameter by introducing multiple diffusers with specific scattering characteristics. The arrangement and properties of the diffusers are optimized to transform the angular distribution of the output signal, achieving broader illumination angles through controlled parameter changes in the optical system.
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 apparatus achieves a higher signal-to-noise ratio by reducing speckle noise and appears to emanate from a larger effective optical source, while also modifying the angular field-of-illumination, thereby improving the illumination pattern and reducing the contribution of undesirable twice-forward-transmitted optical signals.
Implementation Method 1
An inventive optical apparatus comprises a first optical diffuser and a second optical diffuser... each optical diffuser has corresponding opposite input and output faces... One or more forward-propagating input optical signals... are incident on the input face of the first optical diffuser... At least a portion of each one of those input optical signals is redirected or transformed by the first optical diffuser into a corresponding first forward-directed optical signal
Implementation Method 2
at least a portion of each first forward-directed optical signal incident on the input face of the second optical diffuser is redirected or transformed by the second optical diffuser into a corresponding second forward-directed optical signal... each second forward-directed optical signal differs from the corresponding first forward-directed optical signal
Implementation Method 3
The corresponding second forward-directed optical signals... collectively comprise optical output of the optical apparatus... The optical output can exhibit reduced noise due to optical speckle
Data Source
AI summary
Input optical signals propagate toward first optical diffuser, resulting in first-forward-directed optical signals that propagate toward a second optical diffuser, in turn resulting in second forward-directed optical signals. The second forward-directed optical signals collectively form the optical output of an illumination source that appears to emanate from an enlarged extended source and exhibits reduced speckle. The illumination source can include multiple laser sources formed on or attached to the first optical diffuser.