Journal
OPTICS EXPRESS
Volume 27, Issue 15, Pages 20231-20240Publisher
OPTICAL SOC AMER
DOI: 10.1364/OE.27.020231
Keywords
-
Categories
Funding
- Horizon 2020 Framework Program [665158]
- H2020 European Research Council project [681379]
- UK's Engineering and Physical Sciences Research Council [EP/P021859/1]
- EPSRC [EP/P021859/1] Funding Source: UKRI
Ask authors/readers for more resources
Miniaturized frequency combs (FCs) can be self-generated at terahertz (THz) frequencies through four-wave mixing in the cavity of a quantum cascade laser (QCL). To date. however, stable comb operation is only observed over a small operational current range in which the bias-depended chromatic dispersion is compensated. As most dispersion compensation techniques in the THz range are not tunable, this limits the spectral coverage of the comb and the emitted output power. restricting potential applications in. for example. metrology and ultrashort THz pulse generation. Here, we demonstrate an alternative architecture that provides a tunable, lithographically independent, control of the free-running coherence properties of THz QCL FCs. This is achieved by integrating an on-chip tightly coupled mirror with the QCL cavity, providing an external cavity and hence a tunable Gires Tournois interferometer (GTI). By finely adjusting the gap between the GTI and the back-facet of an ultra-broadband, high dynamic range QCL, we attain wide dispersion compensation regions, where stable and narrow (similar to 3 kHz linewidth) single beatnotes extend over an operation range that is significantly larger than that of dispersion-dominated bare laser cavity counterparts. Significant reduction of the phase noise is registered over the whole QCL spectral bandwidth (1.35 THz). This agile accommodation of a tunable dispersion compensator will help enable uptake of QCL-combs for metrological, spectroscopic and quantum technology-oriented applications. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available