Abstract
When two resonant modes in a system with gain or loss coalesce in both their resonance position and their width, a so-called exceptional point occurs, which acts as a source of non-trivial physics in a diverse range of systems. Lasers provide a natural setting to study such non-Hermitian degeneracies, as they feature resonant modes and a gain material as their basic constituents. Here we show that exceptional points can be conveniently induced in a photonic molecule laser by a suitable variation of the applied pump. Using a pair of coupled microdisk quantum cascade lasers, we demonstrate that in the vicinity of these exceptional points the coupled laser shows a characteristic reversal of its pump dependence, including a strongly decreasing intensity of the emitted laser light for increasing pump power.
Original language | English (US) |
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Article number | 4034 |
Journal | Nature communications |
Volume | 5 |
DOIs | |
State | Published - Jun 13 2014 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Biochemistry, Genetics and Molecular Biology
- General Physics and Astronomy