High-power density, single plasmon, terahertz quantum cascade lasers via transverse mode control

Terahertz (THz) quantum cascade lasers (QCLs) have been shown to emit peak powers greater than 1 W from a single facet in a single plasmon geometry. However, this is typically achieved by increasing the laser ridge width, resulting in higher-order transverse modes, limiting the achievable power density. Here, we control and fully suppress these modes through thin metallic side-absorbers, showing laser action solely on the fundamental transverse mode operation without sacrificing high THz peak powers. This leads to enhanced power densities and electric fields of up to 1.8 kW/cm(2) and 1.17 kV/cm, respectively, opening up the possibility of applying THz QCLs as pump sources for investigations of nonlinear THz physical phenomena.

Automated summary

By using thin metallic side-absorbers, researchers have successfully suppressed higher-order transverse modes in Terahertz quantum cascade lasers (THz QCLs), allowing the lasers to operate solely on the fundamental transverse mode without sacrificing high power outputs. This breakthrough opens up opportunities for investigating nonlinear THz physical phenomena using THz QCLs as pump sources.