Large-area periodically-poled lithium niobate wafer stacks optimized for high-energy narrowband terahertz generation.

Periodically-poled lithium niobate (PPLN) sources consisting of custom-built stacks of large-area wafers provide a unique opportunity to systematically study the multi-cycle terahertz (THz) generation mechanism as they are assembled layer-by-layer. Here we investigate and optimize the THz emission from PPLN wafer stacks as a function of wafer number, pump fluence, pulse duration and chirp, wafer separation, and pump focusing. Using 135 µm-thick, 2"-diameter wafers we generate high-energy, narrowband THz pulses with central frequencies up to 0.

Myocarditis in SARS-CoV-2 negative patients with suspected preceding infection.

SARS-CoV-2 is primarily a respiratory disease; however, there have been multiple reports of associated myocarditis. In our 463 bedded, district general hospital, we noted an influx of young patients with myocarditis shortly after the peak of the outbreak. We report two cases presenting with myocarditis, both of whom tested negative for the virus despite clinical and biochemical evidence of recent infection.