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Updated: Jun 9, 2026
12:14
The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
Gaussian beams from variable groove depth grating couplers in planar waveguides.
Applied Optics
|September 8, 2010
Summary
Researchers fabricated a variable groove depth grating coupler for waveguides. This device can shape light beams, demonstrating a method to produce a Gaussian beam profile using ion-beam etching.
Area of Science:
- Photonics
- Optical Engineering
- Waveguide Technology
Background:
- Grating couplers are essential for efficiently coupling light into and out of planar waveguides.
- Controlling the output beam profile from waveguide devices is crucial for integrated optics applications.
- Existing grating couplers often produce fixed output profiles, limiting their versatility.
Purpose of the Study:
- To analyze, fabricate, and characterize variable groove depth (VGD) planar waveguide grating couplers.
- To develop a formula for designing VGD gratings to achieve arbitrary output beam profiles.
- To demonstrate the fabrication of a VGD grating coupler capable of producing a Gaussian beam profile.
Main Methods:
- Derivation of a theoretical formula relating grating groove depth variation to output beam profile.
- Fabrication of a VGD grating coupler on a waveguide using ion-beam etching.
- Utilizing a photoresist grating as a mask for precise ion-beam etching.
- Characterization of the outcoupled beam's near-field irradiance profile.
Main Results:
- Successful derivation of a formula for VGD grating design.
- Fabrication of a VGD grating coupler with a scanning slit apparatus.
- Experimental measurement showing the outcoupled beam's near-field irradiance closely approximates a Gaussian profile.
- Demonstration of precise control over the output beam shape.
Conclusions:
- Variable groove depth grating couplers offer a method for controlling the output beam profile from waveguides.
- The developed fabrication technique allows for the precise creation of complex grating structures.
- This technology has potential applications in integrated optics and optical beam shaping.
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