Polariton relaxation and polariton nonlinearities in nonresonantly cw-pumped III-nitride slab waveguides

Joachim Ciers; D. D. Solnyshkov; G. Callsen; Y. Kuang; J-F Carlin; G. Malpuech; R. Butte; N. Grandjean

doi:10.1103/PhysRevB.102.155304

Polariton relaxation and polariton nonlinearities in nonresonantly cw-pumped III-nitride slab waveguides
Artikel i vetenskaplig tidskrift, 2020

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 K we observe the signature of polariton nonlinearities occurring in the continuous wave regime that are assigned to an optical parametric oscillation process.