Hybrid plasmonic cavities and the understanding of thermal effects in nanoresonators
One of our goals was specifically to explore the use of metals in combination with scaled laser cavities. In this work, we explored the use of metal-cladding (Au) on InP micro-disc lasers. We found that metal-clad cavities show lasing down to smaller dimensions (~300nm) and more stable lasing at higher powers compared to purely dielectric cavities. Not surprisingly, the use of metals did increase the lasing threshold slightly for room-temperature operated devices [9]. It is difficult to establish experimentally whether a given lasing mode is a hybrid photonic-plasmonic or a conventional photonic mode. However, what we did establish is that the use of a metal cavity dramatically improves the heat-sinking capability and hence reduces the temperatures reached in the nanolasers with hundreds of degrees during operation compared to purely dielectric cavities. In a follow-up work this was verified experimentally by the use of calibrated Raman measurements [8].
![Figure 3 Demonstrations of the impact of metal in microdisk lasers: (a) Au nano antenna is used to obtain single-mode lasing and improve temperature stability [7], (b) light-in light-out curve of metal clad hexagonal micro-disk laser [9], and (c) thermal simulation of square micro-disk lasers with and without an Au cladding [8].](/sites/default/files/styles/primer_full_xl/public/2023-03/zz.png.webp?itok=mCouw658 "Figure 3 Demonstrations of the impact of metal in microdisk lasers: (a) Au nano antenna is used to obtain single-mode lasing and improve temperature stability [7], (b) light-in light-out curve of metal clad hexagonal micro-disk laser [9], and (c) thermal simulation of square micro-disk lasers with and without an Au cladding [8].")
Recently we investigated the use of Au nano-antennae coupled to InP microdisk lasers [7]. The optimized placement of an Au nano-antenna led to significant side-mode suppression, whereby single-mode lasing could be established. It also improved the temperature stability of the lasing wavelength compared to samples without the nano-antenna.
Main recent publications:
6. P. Tiwari, A. Fischer, M. Scherrer, D. Caimi, H. Schmid, and K. E. Moselund, “Single-Mode Emission in InP Microdisks on Si Using Au Antenna”, ACS Photonics 9 (4), 1218-1225(2022)
7. P. Wen, P.Tiwari, M. Scherrer, E. Lörtscher, B. Gotsmann, and K. E. Moselund, “Thermal Simulation and Experimental Analysis of Optically Pumped InP-on-Si Micro- and Nanocavity Lasers”, ACS Photonics 9 (4), 1338-1348 (2022)
8. P. Tiwari, P. Wen, D. Caimi, S. Mauthe, N.Vico Triviño, M. Sousa, and K. E. Moselund, "Scaling of metal-clad InP nanodisk lasers: optical performance and thermal effects," Opt. Express 29, 3915 (2021)