Raab, Juergen and Mezzapesa, Francesco P. and Viti, Leonardo and Dessmann, Nils and Diebel, Laura K. and Li, Lianhe and Davies, A. Giles and Linfield, Edmund H. and Lange, Christoph and Huber, Rupert and Vitiello, Miriam S. (2020) Ultrafast terahertz saturable absorbers using tailored intersubband polaritons. NATURE COMMUNICATIONS, 11 (1): 4290. ISSN 2041-1723,
Full text not available from this repository. (Request a copy)Abstract
Semiconductor heterostructures have enabled a great variety of applications ranging from GHz electronics to photonic quantum devices. While nonlinearities play a central role for cutting-edge functionality, they require strong field amplitudes owing to the weak light-matter coupling of electronic resonances of naturally occurring materials. Here, we ultrastrongly couple intersubband transitions of semiconductor quantum wells to the photonic mode of a metallic cavity in order to custom-tailor the population and polarization dynamics of intersubband cavity polaritons in the saturation regime. Two-dimensional THz spectroscopy reveals strong subcycle nonlinearities including six-wave mixing and a collapse of light-matter coupling within 900fs. This collapse bleaches the absorption, at a peak intensity one order of magnitude lower than previous all-integrated approaches and well achievable by state-of-the-art QCLs, as demonstrated by a saturation of the structure under cw-excitation. We complement our data by a quantitative theory. Our results highlight a path towards passively mode-locked QCLs based on polaritonic saturable absorbers in a monolithic single-chip design. Structures that can enhance the capabilities of quantum cascade lasers are highly sought after to improve their practicality for a range of applications. Here the authors demonstrate such a structure in a saturable absorber that takes advantage of intersubband polaritons in the terahertz range and study coherent nonlinear dynamics in the system.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | QUANTUM CASCADE LASERS; PULSES; GENERATION; ABSORPTION; LIGHT; |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Rupert Huber |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 17 Mar 2021 09:59 |
| Last Modified: | 17 Mar 2021 09:59 |
| URI: | https://pred.uni-regensburg.de/id/eprint/43978 |
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