Rectified diode response of a multimode quantum cascade laser integrated terahertz transceiver

TL;DR

This study investigates the diode response within a terahertz quantum cascade laser transceiver, revealing how internal laser fields influence diode behavior and the effects of mode transitions on the response.

Contribution

It provides the first detailed characterization of the diode's DC response in a multimode THz quantum cascade laser, highlighting the coupling between internal laser fields and the integrated diode.

Findings

Diode response includes non-linear rectification and thermal effects.

Sudden jumps in diode response occur during mode transitions.

Internal laser fields directly couple to the integrated diode.

Abstract

We characterized the DC transport response of a diode embedded in a THz quantum cascade laser as the laser current was changed. The overall response is described by parallel contributions from the rectification of the laser field due to the non-linearity of the diode I-V and from thermally activated transport. Sudden jumps in the diode response when the laser changes from single mode to multi-mode operation, with no corresponding jumps in output power, suggest that the coupling between the diode and laser field depends on the spatial distribution of internal fields. The results demonstrate conclusively that the internal laser field couples directly to the integrated diode.