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Frequency Comb Generation by Bloch Gain Induced Giant Kerr Nonlinearity
Nikola Opačak1, Sandro Dal Cin1, Johannes Hillbrand1
1Institute of Solid State Electronics, TU Wien, Gusshausstrasse 25-25a, 1040 Vienna, Austria.
Physical Review Letters
|September 10, 2021
Summary
Bloch gain, a nonclassical phenomenon, is essential for optical frequency comb formation in quantum cascade lasers. This discovery enables electrically driven Kerr combs and frequency modulated combs.
Area of Science:
- Quantum optics
- Semiconductor physics
Background:
- Optical nonlinearities couple light's amplitude and phase, forming optical frequency combs.
- Bloch gain, a nonclassical phenomenon, was predicted in the 1930s.
Purpose of the Study:
- To investigate the role of Bloch gain in optical frequency comb formation.
- To develop a theoretical model for comb dynamics.
Main Methods:
- Developed a self-consistent theoretical model.
- Considered band structure, electron transport, and cavity dynamics.
Main Results:
- Bloch gain induces giant Kerr nonlinearity in quantum cascade lasers.
- Bloch gain enables frequency modulated combs and is the origin of the linewidth enhancement factor.
- Bloch gain triggers solitonlike structures in ring resonators.
Conclusions:
- Bloch gain is crucial for generating optical frequency combs.
- This research paves the way for electrically driven Kerr combs.
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