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Spectral characterization of second harmonic chi((2)) cascading phenomena
Optics Express
|May 8, 2009
Summary
Researchers measured cascading phenomena using second harmonic generation in barium borate crystals. The study revealed competition between nonlinear optical effects, chi(2) and chi(3), under specific phase mismatch conditions.
Area of Science:
- Nonlinear Optics
- Quantum Optics
- Materials Science
Background:
- Second harmonic generation (SHG) is a key nonlinear optical process.
- Cascading phenomena involve sequential nonlinear interactions.
- Barium borate (BBO) crystals are widely used for nonlinear frequency conversion.
Purpose of the Study:
- To measure chi((2)) cascading phenomena in the spectral domain.
- To investigate the spectral evolution of fundamental and harmonic pulses.
- To evidence high-order cascading effects and competition between chi(2) and chi(3) phenomena.
Main Methods:
- Utilizing second harmonic generation in a thin ss-barium borate crystal.
- Inducing harmonic generation with two spectrally filtered femtosecond pulses.
- Analyzing spectral density of fundamental and harmonic pulses for new spectral components.
Main Results:
- Observed new spectral components in both fundamental and harmonic pulses.
- Provided evidence for high-order cascading phenomena.
- Demonstrated competition between cascaded chi(2) and chi(3) phenomena for large phase mismatch, aligning with theoretical predictions.
Conclusions:
- Second harmonic generation in BBO is effective for studying spectral cascading.
- The spectral evolution reveals complex nonlinear interactions.
- Theoretical predictions of chi(2) and chi(3) competition are validated experimentally.
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