Abstract

We present a new heterogeneous terahertz quantum cascade laser dual color comb source featuring two active region designs integrated in the same waveguide. The two central frequencies are spaced by exactly one octave in frequency, namely 2.3 THz and 4.6 THz. The structure is engineered in a way that allows simultaneous operation of the two active regions in the comb regime. Narrow (< 4 KHz) RF beatnotes at 20.12 GHz for the 2.3 THz section and 18.25 GHz for the 4.6 THz one are recorded. The combination of this source with an engineered internal non-linear section would pave the way towards a fully on-chip f-2f interferometer.

© 2018 The Author(s)