RF Injection Locking of THz Metasurface Quantum-Cascade VECSEL
Abstract
RF injection locking and spectral broadening of a terahertz (THz) quantum-cascade vertical-external-cavity surface-emitting laser (QC-VECSEL) is demonstrated. An intra-cryostat VECSEL focusing cavity design is used to enable continuous-wave lasing with a cavity length over 30 mm which corresponds to a round-trip frequency near 5 GHz. Strong RF current modulation is injected to the QC-metasurface electrical bias to pull and lock the round-trip frequency. The injection locking range at various RF injection powers is recorded and compared with the injection locking theory. Moreover, the lasing spectrum broadens from 14 GHz in free-running mode to a maximum spectral width around 100 GHz with 20 dBm of injected RF power. This experimental setup is suitable for further exploration of active mode-locking and picosecond pulse generation in THz QC-VECSELs.
Keywords
Cite
@article{arxiv.2301.04806,
title = {RF Injection Locking of THz Metasurface Quantum-Cascade VECSEL},
author = {Yu Wu and Christopher A. Curwen and Mohammad Shahili and John L. Reno and Benjamin S. Williams},
journal= {arXiv preprint arXiv:2301.04806},
year = {2023}
}