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Updated: May 24, 2026
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Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
Adaptive slit beam shaping for direct laser written waveguides
P S Salter1, A Jesacher, J B Spring
1Department of Engineering Science, University of Oxford, Oxford, United Kingdom. patrick.salter@eng.ox.ac.uk
Optics Letters
|February 21, 2012
Summary
We developed a new femtosecond laser writing technique using a spatial light modulator (SLM) to precisely shape laser beams. This method allows for the fabrication of complex optical waveguides with low loss in fused silica.
Area of Science:
- Photonics and Optical Engineering
- Materials Science
- Laser Technology
Background:
- Femtosecond laser writing is a key technique for fabricating optical waveguides.
- Existing methods have limitations in creating complex structures.
- Real-time beam control is needed for advanced waveguide fabrication.
Purpose of the Study:
- To demonstrate an improved femtosecond laser writing method for optical waveguides.
- To enable the fabrication of more complex waveguide structures.
- To reduce fabrication complexity and improve precision.
Main Methods:
- Utilized a liquid crystal spatial light modulator (SLM) for adaptive beam shaping.
- Employed a diffraction grating on the SLM to create slit illumination.
- Implemented real-time control of beam-shaping parameters during laser writing.
Main Results:
- Successfully fabricated optical waveguides in bulk fused silica.
- Achieved low coupling loss to single-mode fibers (0.2–0.5 dB).
- Demonstrated low propagation loss (<0.4 dB/cm).
Conclusions:
- The SLM-based adaptive beam shaping offers enhanced control over waveguide fabrication.
- This technique facilitates the creation of intricate optical waveguide designs.
- The method yields high-performance waveguides with minimal optical losses.
