Abstract
Polariton lasers are mostly based on planar cavities. Here we focus on an alternative configuration with slab waveguide modes strongly coupled to excitons confined in GaN/AlGaN quantum wells. We study experimentally and theoretically polariton relaxation at temperatures ranging from 4 to 200 K. We observe a good robustness of the lower polariton population peak energy position against temperature changes due to a balance between the shift of the exciton energy and the change in the normal mode splitting, a promising feature for future applications such as lasers and amplifiers where a small temperature drift in the emission wavelength is a desired asset. Finally, at $T=4\phantom{\rule{4pt}{0ex}}\mathrm{K}$ we observe the signature of polariton nonlinearities occurring in the continuous wave regime that are assigned to an optical parametric oscillation process.
Highlights
When the decay rates of both semiconductor excitons and confined optical modes are slower than their mutual rate of energy exchange, the eigenmodes of the system are hybrid light-matter quasiparticles called exciton-polaritons or polaritons [1,2]
With the aim of realizing ever more complex polaritonic WG circuits, such as cascading devices, there is a need for a precise understanding of some key features such as the impact of temperature and optical pump power on polariton relaxation for this specific geometry and whether observing polariton nonlinearities in the continuous wave regime in other materials than the prototypical GaAs-based system is within reach
We observe that the lower polaritons (LPs) branch (LPB) intensity decreases with temperature relative to the nondispersive photoluminescence (PL) background, making it impossible to observe the LPB above 200 K
Summary
When the decay rates of both semiconductor excitons and confined optical modes are slower than their mutual rate of energy exchange (the Rabi splitting), the eigenmodes of the system are hybrid light-matter quasiparticles called exciton-polaritons or polaritons [1,2]. With the aim of realizing ever more complex polaritonic WG circuits, such as cascading devices, there is a need for a precise understanding of some key features such as the impact of temperature and optical pump power on polariton relaxation for this specific geometry and whether observing polariton nonlinearities in the continuous wave (cw) regime in other materials than the prototypical GaAs-based system is within reach In this regard, developing platforms where polaritons exhibit a recognized robustness to their environment thanks to their large exciton binding energy (EXb ), like operation up to ambient temperature, is a highly desirable asset. Within this framework we report polariton nonlinearities, which are well accounted for using the formalism of the GrossPitaevskii equation (GPE)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
