1.
Opt Lett
; 44(13): 3314-3317, 2019 Jul 01.
Artigo
em Inglês
| MEDLINE
| ID: mdl-31259948
RESUMO
We report on the high detection sensitivity of a laser feedback interferometry scheme based on a terahertz frequency quantum cascade laser (QCL). We show that variations on the laser voltage induced by optical feedback to the laser can be resolved with the reinjection of powers as low as â¼-125 dB of the emitted power. Our measurements demonstrate a noise equivalent power of â¼1.4 pW/âHz, although, after accounting for the reinjection losses, we estimate that this corresponds to only â¼1 fW/âHz being coupled to the QCL active region.