Active phase-nulling of the self-mixing phase in a terahertz frequency quantum cascade laser.
Opt Lett
; 40(6): 950-3, 2015 Mar 15.
Article
in En
| MEDLINE
| ID: mdl-25768154
ABSTRACT
We demonstrate an active phase-nulling scheme for terahertz (THz) frequency quantum cascade lasers (QCLs) under optical feedback, by active electronic feedback control of the emission frequency. Using this scheme, the frequency tuning rate of a THz QCL is characterized, with significantly reduced experimental complexity compared to alternative approaches. Furthermore, we demonstrate real-time displacement sensing of targets, overcoming the resolution limits imposed by quantization in previously implemented fringe-counting methods. Our approach is readily applicable to high-frequency vibrometry and surface profiling of targets, as well as frequency-stabilization schemes for THz QCLs.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Opt Lett
Year:
2015
Document type:
Article