Researchers created a periodically poled van der Waals semiconductor (3R-MoS2) and achieved a macroscopic frequency conversion efficiency of 0.03% over a thickness of 3.4 μm. The quasi-phase-matched second harmonic signal surpasses the usual quadratic enhancement by 50% and broadband generation of photon pairs at telecom wavelength is demonstrated with a coincidence-to-accidental ratio of 638 ± 75.
- Chiara Trovatello
- Carino Ferrante
- P. James Schuck
