PT Unknown
AU Hovenier J.N.
   Adam A.J.L.
   Kašalynas I.
   Gao J.R.
   Klaassen T.O.
   Baryshev A.
   Williams B.S.
   Kumar S.
   Hu Q.
   Reno J.L.
TI Phase-locking on the beat signal of a two-mode 2.7  terahertz metal-metal quantum cascade laser
SE Proc. Symp. IEEE/LEOS Benelux Chapter
PY 2006
BP 125
EP 128
AB We have studied the linewidth and phase-locking of a 2.7 THz quantum cascade laser by using a superconducting bolometer mixer. The 8 GHz beat signal is compared with a microwave reference with a feedback to the laser bias current. Phase locking has been demonstrated, resulting in an extremely narrow beat linewidth of less than 10 Hz. Under frequency-stabilization conditions we find that the line profile is virtually Lorentzian with a long-term minimum linewidth of the THz modes of about 6.3 kHz. Temperature dependent measurements suggestthat this linewidthdoes not approach the Schawlow-Townes limit.
ER