Breakthrough: Beyond 300 Gbit/s optical communication speed
Beyond 300 Gbit/s communication speed achieved as a result from collaboration with Finisar.
A collaboration between Finisar and KTH has yielded directly modulated lasers with more than 65 GHz modulation bandwidth [1, 2]. This is the highest modulation bandwidth achieved for monolithic InGaAsP/InP lasers. A side mode was utilized to extend the modulation bandwidth beyond that of conventional semiconductor lasers; a technique that was discovered and pioneered by KTH in the 1990's . Experiments performed at Nokia Bell Labs demonstrates that the lasers can be used for data transmission beyond 300 Gbit/s, using novel multi-level modulation formats. Another benefit is that they are also tolerant to back reflections and can be used without optical isolator, which facilitates their use in optical transceivers in datacenters.
 U. Troppenz & Jochen Kreissl, Semiconductor Lasers: Designs break bandwidth record, Nat. Photonics15, 4–5 (2021). www.nature.com/articles/s41566-020-00739-x
 Y. Matsui., R. Schatz, D. Che, et al. Low-chirp isolator-free 65-GHz-bandwidth directly modulated lasers. Nat. Photonics 15, 59–63 (2021). doi.org/10.1038/s41566-020-00742-2
 O. Kjebon, R. Schatz, S. Lourdudoss, S. Nilsson, B. Stalnacke and L. Backbom, "Two-section InGaAsP DBR-lasers at 1.55 /spl mu/m wavelength with 31 GHz direct modulation bandwidth," Conference Proceedings. 1997 International Conference on Indium Phosphide and Related Materials, Cape Cod, MA, USA, 1997, pp. 665-668, doi: 10.1109/ICIPRM.1997.600265. ieeexplore.ieee.org/document/600265