Related Experiment Video
Updated: Jun 16, 2026
10:17
20 mJ, 1 ps Yb:YAG Thin-disk Regenerative Amplifier
Published on: July 12, 2017
Random quasi-phase-matched second-harmonic generation in periodically poled lithium tantalate
S Stivala1, A C Busacca, A Pasquazi
1DIEET, University of Palermo, 90128 Palermo, Italy.
Optics Letters
|February 4, 2010
Summary
We demonstrate random quasi-phase-matching for second harmonic generation in lithium tantalate, observing broadband output and quadratic growth with fundamental power. This stochastic nonlinear process shows good agreement with theoretical models.
Area of Science:
- Nonlinear optics
- Materials science
Background:
- Periodically poled lithium tantalate is a key material for nonlinear optical frequency conversion.
- Quasi-phase-matching (QPM) enhances nonlinear optical processes but typically requires precise domain engineering.
Purpose of the Study:
- To investigate second harmonic generation (SHG) using random quasi-phase-matching (R-QPM).
- To characterize the SHG output properties in a stochastically poled material.
Main Methods:
- Fabrication of a 2.0 µm periodically poled, 1-cm-long, z-cut lithium tantalate crystal with random domain distribution.
- Experimental measurement of SHG output profiles, spectral response, and power dependence.
- Theoretical modeling and numerical simulations in the undepleted regime.
Main Results:
- Observed SHG via R-QPM in lithium tantalate.
- Harmonic output profiles showed characteristic patterns due to stochastic domain distribution.
- Demonstrated quadratic power dependence and broadband spectral response away from resonance.
- Results agreed well with a model assuming anisotropic spread of the random nonlinear component.
Conclusions:
- Random quasi-phase-matching is a viable mechanism for broadband second harmonic generation.
- Stochastic domain structures can lead to predictable yet broadband nonlinear optical responses.
- The findings provide insights into controlling nonlinear optical effects in engineered materials.
