Anti-speckle technology

Laser speckle reduction without diffusers:

Dyoptyka has developed an innovative solution for the reduction of speckle and other unwanted interference effects that can arise when using coherent light sources.

Our phase-randomizing deformable mirror offers a unique combination of advantages over alternatives such as moving diffusers and shaking fibers with respect to: speckle reduction performance, speed, optical efficiency, electrical efficiency, size, and manufacturability.

We would be happy to offer our opinion on whether our technology is appropriate for your application so feel free to contact us for discussion.

Evaluation Systems

We supply and support evaluation systems suited to your laser power, beam diameter, wavelength, pulse duration, etc.

A typical first evaluation system comprises a 5 mm diameter deformable mirror, mounted in a Thorlabs KCB1 kinematic enclosure for protection and ease of alignment, and and a small electronic control module. No device configuration or software is required.

Subsequent evaluation systems can be customized to meet your application requirements.

Production and supply of larger quantities can be undertaken by our manufacturing partner, a globally-recognized leader in optical coatings and components.

Frequently asked questions

How does our technology compare to a moving diffuser?

Both approaches generate sequences of uncorrelated speckle patterns which sum to a more homogeneous intensity over the exposure period. A diffuser must have a short correlation length of surface roughness so that it does not need to be moved at impractically high speed. The consequent diffraction into wide angles can greatly reduce optical efficiency. The deformable mirror has a continuous surface with relatively long correlation lengths. Its effect can be understood as narrow-angle temporally-randomized divergence. Randomly-distributed deformations in the continuous surface at very high temporal frequencies lead to the generation of many uncorrelated speckle patterns, e.g. within a single one microsecond laser pulse.

How does our technology compare to shaking multimode fiber?

The spot on the deformable mirror (from where the incident beam is reflected) can be imaged into the entrance face of a stationary multimode fiber with high coupling efficiency. Sequences of uncorrelated modal patterns are generated at the fiber exit face which sum to a more homogeneous intensity over the exposure period. Shaking fiber can achieve a similar effect but with lower temporal frequency, longer fiber length, higher N.A., larger core diameter; and the risk of fiber failure due to dynamic fatigue.

What wavelengths, optical powers, and pulse lengths can be used?

Our systems are currently being used by customers with wavelengths ranging from 215 nm to 10.6 um (with reflection efficiency up to 99%, depending on coating,) with CW optical powers up to 100 W, and pulse lengths as short as 1 us.

In what types of optical system has the technology been used?

Projection and holographic display, microscopy, interferometry, photolithography, metrology, sensor calibration, target illumination, and many more customer applications in both free-space and fiber-coupled configurations.

Publications

General overview

Phase randomization for spatio-temporal averaging of unwanted interference effects arising from coherence

Applied Optics, Vol. 57, Issue 22, pp. E6-E10 (OSA, 2018) Article.

Speckle reduction solutions

4th Huawei Optical Innovations Summit, München, Germany, September 2020. Slides

Speckle reduction performance estimation

Laser Display and Lighting Conference, Yokohama, Japan, April 2024. Abstract

Optical fiber

High-Frequency Homogenization of Laser Illumination Through Stationary 0.22 N.A. Multimode Optical Fiber

Laser Display and Lighting Conference, Yokohama, April 2023. Abstract Slides

High-Frequency Homogenization of Laser Illumination Through Stationary 0.39 N.A. Multimode Optical Fiber

Laser Display and Lighting Conference, Yokohama, April 2022. Abstract Slides

Optical efficiency

Homogenization Without Scattering of Laser Illumination

Laser Display and Lighting Conference, Yokohama, April 2019. Abstract Slides

Beam Quality-Preserving Speckle Reduction for Scanned Laser Displays

Laser Display Conference, Yokohama, April 2015. Abstract Slides

High frequency

Speckle reduction within nanosecond-order pulse widths for flash lidar applications

Laser Display and Lighting Conference, Yokohama, April 2020. Abstract Slides Video

Speckle reduction within a single one microsecond laser pulse

International Display Workshop, Kyoto, December 2012. Abstract

Holographic display

Dynamic Illumination for Spatio-temporal Integration of Unwanted Interferences in Holographic Displays

Laser Display and Lighting Conference, Yokohama, April 2018. Abstract Slides

Phosphor downconversion

Directional Illumination with Homogenization of Laser Incidence on Remote Phosphor

Laser Display and Lighting Conference, Jena, July 2016.
Abstract Slides

Speckle reduction for illumination with lasers and stationary, heatsinked, phosphors

International Display Workshop, Sapporo, 2013. Abstract

Light guide plate

Light guide plate illumination with blue laser and quantum dot emission

International Display Workshop, Niigata, December 2014. Abstract

Light guide plate illumination by laser through optical fiber

Laser Display Conference, Taichung, June 2014. Abstract

Projection display

A compact, low cost, phase randomizing device for laser illuminated displays

International Display Workshop, Niigata, December 2014. Abstract

Speckle reduction with multiple laser pulses

Laser Display Conference, Yokohama, April 2013. Winner of best paper award! Presentation

Speckle mitigation in laser-based projectors

Laser Display Conference, Yokohama, April 2012. Presentation

Speckle reduction for laser-illuminated picoprojectors

SPIE Photonics West Conference, San Francisco, January 2012. Article

Gallery

Texas Instruments DLP picoprojector.

Beam profile reflectometry interferometer.

A single one microsecond laser pulse illuminating a grating.

Magneto-optical Kerr Microscope with 50 manometer pixel size at object.

Multimode fiber illumination of materials with different surface roughness.

Round and square multimode fiber, imaged in the near field of exit faces.

References

Our customers, and others, have published several articles and theses describing the use of our technology in various applications. We hope to list them here and provide some commentary, eventually.

This recent review provides an interesting, and independent, comparison:

Kompanets, I. and Zalyapin, N. (2020) Methods and Devices of Speckle-Noise Suppression (Review). Optics and Photonics Journal, 10, 219-250. https://doi.org/10.4236/opj.2020.1010023

Contact

Please contact me directly with any queries.

Email: fshevlin (at) dyoptyka (dot) com .

Looking forward to hearing from you,

Fergal Shevlin Ph.D., Founder.

DYOPTYKA,
Dublin, Ireland.

(Ask me for current billing and shipping addresses and phone numbers.)