[1] J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, A. Y. Cho. Quantum cascade laser. Science, 264, 553(1994).

[2] Y. Yao, A. J. Hoffman, C. F. Gmachl. Mid-infrared quantum cascade lasers. Nat. Photonics, 6, 432(2012).

[3] M. Razeghi, W. Zhou, S. Slivken, Q. Y. Lu, D. Wu, R. McClintock. Recent progress of quantum cascade laser research from 3 to 12 µm at the center for quantum devices [Invited]. Appl. Opt., 56, H30(2017).

[4] L. J. Mawst, D. Botez. High-power mid-infrared (λ∼3–6 µm) quantum cascade lasers. IEEE Photonics J., 14, 1508025(2022).

[5] R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, F. K. Tittel. Quantum cascade lasers in chemical physics. Chem. Phys. Lett., 487, 1(2010).

[6] S. Bartalini, M. S. Vitiello, P. De Natale. Quantum cascade lasers: a versatile source for precise measurements in the mid/far-infrared range. Meas. Sci. Technol., 25, 012001(2014).

[7] C. W. Liu, S. Q. Zhai, J. C. Zhang, Y. H. Zhou, Z. W. Jia, F. Q. Liu, Z. G. Wang. Free-space communication based on quantum cascade laser. J. Semicond., 36, 094009(2015).

[8] Q. Y. Lu, Y. Bai, N. Bandyopadhyay, S. Slivken, M. Razeghi. 2.4 W room temperature continuous wave operation of distributed feedback quantum cascade lasers. Appl. Phys. Lett., 98, 181106(2011).

[9] F. M. Cheng, J. C. Zhang, Y. J. Guan, P. C. Yang, N. Zhuo, S. Q. Zhai, J. Q. Liu, L. J. Wang, S. M. Liu, F. Q. Liu, Z. G. Wang. Ultralow power consumption of a quantum cascade laser operating in continuous-wave mode at room temperature. Opt. Express, 28, 36497(2020).

[10] F. Xie, C. G. Caneau, H. P. LeBlanc, M. T. Ho, J. Wang, S. Chaparala, L. C. Hughes, C. E. Zah. High power and high temperature continuous-wave operation of distributed Bragg reflector quantum cascade lasers. Appl. Phys. Lett., 104, 071109(2014).

[11] P. Q. Liu, K. Sladek, X. J. Wang, J.-Y. Fan, C. F. Gmachl. Single-mode quantum cascade lasers employing a candy-cane shaped monolithic coupled cavity. Appl. Phys. Lett., 99, 241112(2011).

[12] B. Meng, J. Tao, X. H. Li, Y. Q. Zeng, S. Wu, Q. J. Wang. Tunable single-mode slot waveguide quantum cascade lasers. Appl. Phys. Lett., 104, 201106(2014).

[13] K. Fujita, S. Jung, Y. Jiang, J. H. Kim, A. Nakanishi, A. Ito, M. Hitaka, T. Edamura, M. A. Belkin. Recent progress in terahertz difference-frequency quantum cascade laser sources. Nanophotonics, 7, 1795(2018).

[14] J. Jagerska, P. Jouy, A. Hugi, B. Tuzson, H. Looser, M. Mangold, M. Beck, L. Emmenegger, J. Faist. Dual-wavelength quantum cascade laser for trace gas spectroscopy. Appl. Phys. Lett., 105, 161109(2014).

[15] F. Kapsalidis, M. Shahmohammadi, M. J. Suess, J. M. Wolf, E. Gini, M. Beck, M. Hundt, B. Tuzson, L. Emmenegger, J. Faist. Dual-wavelength DFB quantum cascade lasers: sources for multi-species trace gas spectroscopy. Appl. Phys. B, 124, 107(2018).

[16] Y. J. Guan, L. J. Wang, N. Zhuo, J. C. Zhang, S. Q. Zhai, J. Q. Liu, S. M. Liu, F. Q. Liu. Dual-wavelength switchable, mid-infrared quantum cascade laser with two shallow-etched distributed Bragg reflectors. Opt. Express, 29, 39376(2021).

[17] A. Bismuto, R. Terazzi, M. Beck, J. Faist. Electrically tunable, high performance quantum cascade laser. Appl. Phys. Lett., 96, 141105(2010).

[18] H. Kogelnik, C. V. Shank. Coupled-wave theory of distributed feedback lasers. J. Appl. Phys., 43, 2327(1972).

[19] Q. Y. Lu, W. Zhang, L. J. Wang, J. Q. Liu, L. Li, F. Q. Liu, Z. G. Wang. Holographic fabricated photonic-crystal distributed-feedback quantum cascade laser with near-diffraction-limited beam quality. Opt. Express, 17, 18900(2009).

[20] A. Evans, S. R. Darvish, S. Slivken, J. Nguyen, Y. Bai, M. Razeghi. Buried heterostructure quantum cascade lasers with high continuous-wave wall plug efficiency. Appl. Phys. Lett., 91, 071101(2007).