Journal of Infrared and Millimeter Waves, Volume. 42, Issue 6, 762(2023)
Progress in the study of nonlinear dynamic characteristics based on quantum cascade lasers
Fig. 1. (a) Optical spectra vs. pumping ratio (
Fig. 2. (a) Experimental time traces of the QCL under the optical feedback at 77 K. The polarizer allows achieving the value of feedback ratio f between 0 and 0.089,a) f = 0,b) f = 0.000 3,c) f = 0.000 8,d) f = 0.004 6,e) f = 0.014 1,f) f = 0.021 3,g) f = 0.029 8,h) f = 0.039 3,i) f = 0.089,(b) simulation of the upper state lifetime evolution with temperature for the QCL under study[30]
Fig. 4. Fix one of the external cavities with the length 0.75 m and the feedback strength 0.22,(a) another external cavity with the length 0.45 m and the feedback strength 0.022,(b) Fourier spectrum corresponding to (a),(c) another external cavity with the length 0.6 m and the feedback strength 0.022,(d) Fourier spectrum corresponding to (c)
Fig. 5. Local bifurcation diagram of an injection-locked QC laser for linewidth enhancement factor (LEF) values of 0,0.5,1.0,and 2.5. The solid line is the saddle node (SN) bifurcation and the dashed line is the Hopf bifurcation. The supercritical bifurcation is denoted by the thick lines while the subcritical bifurcation by the thin lines. The stable locking regime is bounded by the supercritical bifurcations. The investigated laser is operating in the stable locked region of the bifurcation diagram with an LEF of 0.5,where the vertical dotted line indicates an injection ratio of 5.0[40]
Fig. 6. (a) Time series under sine wave signal modulation,(b) RF spectrum under sine wave signal modulation,(c) time series under square wave signal modulation,(d) RF spectrum under square wave signal modulation. I: continuous pump current,A: peak-to-peak amplitude of the modulation,F: frequency of the modulation[48]
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Wei FENG, Yu MAO, Yue MENG, Tian-Liang RENG, Chang WANG, Jun-Cheng CAO. Progress in the study of nonlinear dynamic characteristics based on quantum cascade lasers[J]. Journal of Infrared and Millimeter Waves, 2023, 42(6): 762
Category: Research Articles
Received: Feb. 21, 2023
Accepted: --
Published Online: Dec. 26, 2023
The Author Email: Chang WANG (cwang@mail.sim.ac.cn), Jun-Cheng CAO (jccao@mail.sim.ac.cn)