High efficiency coupling of Terahertz micro-ring quantum cascade lasers to the low-loss optical modes of hollow metallic waveguides.
We demonstrate that azimuthally polarized surface emitting Terahertz quantum cascade lasers fabricated in a micro-ring resonator geometry can be coupled to cylindrical hollow aluminum waveguides reaching efficiencies as high ≈98%, when a collimating lens is used. By placing the waveguide in close contact with the QCL in a simple back-to-back geometry, the laser mode can be perfectly matched with the low loss TE(01) waveguide mode showing attenuation losses as low as ≈2.3-2.7 dB/m at 3.2 THz.
CNR-Istituto Nazionale di Fisica Applicata Nello Carrara, Sesto Fiorentino, Italy. miriam.vitiello@sns.it
Miriam S
MS
Vitiello
Ji-Hua
JH
Xu
Mirgender
M
Kumar
Fabio
F
Beltram
Alessandro
A
Tredicucci
Oleg
O
Mitrofanov
Harvey E
HE
Beere
David A
DA
Ritchie
D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D008670:Metals / Q000737:chemistry*; D008904:Miniaturization; D012031:Refractometry / Q000295:instrumentation*; D055053:Terahertz Radiation; D014159:Transducers
D008670:Metals