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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
Amplitude modulation and apodization of quasiphase-matched interactions
Jie Huang1, X P Xie, Carsten Langrock
1Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA. jiehuang@stanford.edu
Optics Letters
|March 31, 2006
Summary
We developed new methods to control light interactions in lithium niobate waveguides. This reduces unwanted signal interference in optical communications and enhances frequency conversion devices.
Area of Science:
- Nonlinear optics
- Materials science
- Optical engineering
Background:
- Quasi-phase-matched (QPM) interactions are crucial for nonlinear optical processes.
- Periodically poled lithium niobate (PPLN) waveguides are widely used for QPM devices.
- Modulating the amplitude of nonlinear coupling can impact device performance.
Purpose of the Study:
- To propose and demonstrate techniques for modulating the local amplitude of QPM interactions.
- To investigate the effect of amplitude modulation on frequency tuning curves.
- To enhance the performance of frequency conversion devices.
Main Methods:
- Utilizing techniques to modulate the local amplitude of QPM interactions in PPLN waveguides.
- Implementing apodization by modifying the spatial profile of nonlinear coupling.
- Comparing frequency tuning curves with uniform gratings and apodized gratings.
Main Results:
- Apodization successfully suppressed sidelobes in frequency tuning curves by 13 dB or more.
- Removal of hard edges in the nonlinear coupling profile led to significant sidelobe reduction.
- Results align with theoretical predictions for apodized gratings.
Conclusions:
- Amplitude modulation techniques offer control over tuning curve shapes.
- Sidelobe-suppressed gratings are beneficial for optical communication systems, minimizing interchannel cross talk.
- These techniques have broad potential in applications requiring tailored tuning curve characteristics.
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