Optical Diffuser Substrate for Laser Speckle Reduction
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Solution Overview
Problem
Conventional wide-angle illumination systems suffer from noise due to laser speckle and have limited angular field-of-illumination, and they minimize backward-directed optical signals which are considered undesirable.
Innovation Solution
An optical apparatus comprising a diffuser substrate and an optical diffuser that redirects and transforms incident optical signals into forward-directed and backward-directed signals, increasing the effective size of the illumination source and reducing noise by creating additional virtual incoherent sources, thereby enhancing the signal-to-noise ratio and angular field-of-illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional wide-angle illumination systems minimize backward-directed optical signals, then device complexity is reduced, but noise due to laser speckle increases and angular field-of-illumination is limited
Solution Approach 1:
The patent converts the previously harmful backward-directed optical signals into a beneficial resource. By intentionally generating and utilizing backward-directed optical signals that propagate through the diffuser substrate, the system creates additional virtual incoherent sources that reduce laser speckle noise. This transforms what was considered waste or harmful radiation into a useful mechanism for noise reduction and angular field expansion.
Solution Approach 2:
The diffuser substrate acts as an intermediary medium that enables the conversion of backward-directed optical signals into useful forward-directed illumination. The substrate's diffusing properties transform the directional backward signals into multiple scattered paths, creating virtual sources that reduce speckle while expanding the angular field of illumination.
2Adaptability or versatility
If conventional systems use standard optical diffusers, then manufacturing is simplified, but angular field-of-illumination remains limited
Solution Approach 1:
The patent merges the functions of the diffuser substrate and optical diffuser into a integrated structure where backward-directed signals are intentionally generated and utilized. This combination creates a unified optical path that simultaneously achieves wide angular illumination and maintains manufacturing simplicity by using conventional diffuser technologies.
Solution Approach 2:
The patent adds a temporal and spatial dimension to the illumination by creating multiple virtual sources through the backward signal path. This effectively increases the apparent source size and angular coverage without adding physical complexity to the basic diffuser structure.
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 reduces noise due to laser speckle and increases the effective size of the illumination source, resulting in a wider angular field-of-illumination and improved signal-to-noise ratio compared to conventional systems.
Implementation Method 1
an optical diffuser that redirects and transforms incident optical signals into forward-directed and backward-directed signals
Implementation Method 2
an optical diffuser attached to or formed on a diffuser substrate output surface or formed within the diffuser substrate
Implementation Method 3
At least a portion of each backward-directed optical signal is in turn redirected or transformed into one or more corresponding incident optical signals propagating within the diffuser substrate toward the output surface
Data Source
AI summary
Incident optical signals propagate within a diffuser substrate and impinge upon an optical diffuser within the diffuser substrate or on its output surface. The optical diffuser redirects or transforms respective portions of each incident signal into corresponding forward- and backward-directed optical signals. The backward-directed signals are redirected or transformed into additional incident signals, and so on. The forward-directed optical signals collectively form the optical output of an illumination source that exhibits reduced speckle. The illumination source can include multiple laser sources formed on or attached to an input surface of the diffuser substrate.