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Non-moving Hadamard matrix diffusers for speckle reduction in laser pico-projectors.
Weston Thomas1, Christopher Middlebrook1
1Electrical Engineering Department, Michigan Technological University , Houghton , MI , USA.
Journal of Modern Optics
|February 24, 2015
Summary
Researchers developed a novel Hadamard diffusers to reduce laser speckle in pico-projectors. This innovation minimizes eye strain and headaches, improving the viewing experience for integrated electronic devices.
Area of Science:
- Optics and photonics
- Microelectromechanical systems (MEMS)
Background:
- Personal electronic devices are incorporating advanced features like integrated projectors.
- Laser pico-projectors face challenges with coherent interference, known as speckle, causing visual discomfort.
- Existing diffusers require mechanical movement, adding complexity to pico-projector systems.
Purpose of the Study:
- To investigate a static diffractive optical element for speckle reduction in laser pico-projectors.
- To present and evaluate a binary diffuser based on Hadamard matrices for speckle mitigation.
Main Methods:
- Fabrication of two static in-line Hadamard diffusers.
- Measurement of speckle contrast values.
- Comparison of experimental results with theoretical and simulated values.
Main Results:
- The fabricated Hadamard diffusers effectively reduced speckle contrast.
- Measured contrast values showed good agreement with theoretical predictions and simulations.
- The static nature of the diffusers eliminates the need for mechanical components for temporal averaging.
Conclusions:
- Hadamard matrix diffusers offer a viable solution for reducing laser speckle in pico-projectors.
- Static diffusers simplify pico-projector design by removing the need for rotation or vibration.
- This technology has the potential to enhance user experience and enable wider adoption of pico-projector technology.
