[1] Ebrahim-ZadehM.SorokinaI. T., eds., Mid-Infrared Coherent Sources and Applications (Springer, 2008).

[2] VodopyanovK. L., Laser-Based Mid-Infrared Sources and Applications (Wiley, 2020).

[3] M. Razeghi, B.-M. Nguyen. Advances in mid-infrared detection and imaging: a key issues review. Rep. Prog. Phys., 2014, 77: 082401.

[4] S. Keuleyan, E. Lhuillier, V. Brajuskovic, P. Guyot-Sionnest. Mid-infrared HgTe colloidal quantum dot photodetectors. Nat. Photonics, 2011, 5: 489-493.

[5] Q. Guo, R. Yu, C. Li, S. Yuan, B. Deng, F. Javier García de Abajo, F. Xia. Efficient electrical detection of mid-infrared graphene plasmons at room temperature. Nat. Mater., 2018, 17: 986-992.

[6] J. Bullock, M. Amani, J. Cho, Y.-Z. Chen, G. H. Ahn, V. Adinolfi, V. R. Shrestha, Y. Gao, K. B. Crozier, Y.-L. Chueh, A. Javey. Polarization-resolved black phosphorus/molybdenum disulfide mid-wave infrared photodiodes with high detectivity at room temperature. Nat. Photonics, 2018, 12: 601-607.

[7] F. Marsili, F. Bellei, F. Najafi, A. E. Dane, E. A. Dauler, R. J. Molnar, K. K. Berggren. Efficient single photon detection from 500 nm to 5 μm wavelength. Nano Lett., 2012, 12: 4799-4804.

[8] ChenQ.GeR.ZhangL.LiF.ZhangB.DaiY.FeiY.WangX.JiaX.ZhaoQ.TuX.KangL.ChenJ.WuP., “Mid-infrared single photon detector with superconductor Mo₈₀Si₂₀ nanowire,” arXiv:2011.06699 (2020).

[9] R. H. Hadfield. Single-photon detectors for optical quantum information applications. Nat. Photonics, 2009, 3: 696-705.

[10] T. Gerrits, S. Glancy, T. S. Clement, B. Calkins, A. E. Lita, A. J. Miller, A. L. Migdall, S. W. Nam, R. P. Mirin, E. Knill. Generation of optical coherent-state superpositions by number-resolved photon subtraction from the squeezed vacuum. Phys. Rev. A, 2010, 82: 031802.

[11] N. Namekata, Y. Takahashi, G. Fujii, D. Fukuda, S. Kurimura, S. Inoue. Non-Gaussian operation based on photon subtraction using a photon-number-resolving detector at a telecommunications wavelength. Nat. Photonics, 2010, 4: 655-660.

[12] M. Avenhaus, K. Laiho, M. V. Chekhova, C. Silberhorn. Accessing higher order correlations in quantum optical states by time multiplexing. Phys. Rev. Lett., 2010, 104: 063602.

[13] R. Nehra, A. Win, M. Eaton, R. Shahrokhshahi, N. Sridhar, T. Gerrits, A. Lita, S. W. Nam, O. Pfister. State-independent quantum state tomography by photon-number-resolving measurements. Optica, 2019, 6: 1356-1360.

[14] L. Cohen, E. S. Matekole, Y. Sher, D. Istrati, H. S. Eisenberg, J. P. Dowling. Thresholded quantum LIDAR: exploiting photon-number-resolving detection. Phys. Rev. Lett., 2019, 123: 203601.

[15] F. E. Becerra, J. Fan, A. Migdall. Photon number resolution enables quantum receiver for realistic coherent optical communications. Nat. Photonics, 2015, 9: 48-53.

[16] Y.-H. Zhou, Z.-W. Yu, X.-B. Wang. Making the decoy-state measurement-device-independent quantum key distribution practically useful. Phys. Rev. A, 2016, 93: 042324.

[17] H.-L. Yin, T.-Y. Chen, Z.-W. Yu, H. Liu, L.-X. You, Y.-H. Zhou, S.-J. Chen, Y. Mao, M.-Q. Huang, W.-J. Zhang, H. Chen, M. J. Li, D. Nolan, F. Zhou, X. Jiang, Z. Wang, Q. Zhang, X.-B. Wang, J.-W. Pan. Measurement-device-independent quantum key distribution over a 404 km optical fiber. Phys. Rev. Lett., 2016, 117: 190501.

[18] G. Temporão, S. Tanzilli, H. Zbinden, N. Gisin, T. Aellen, M. Giovannini, J. Faist. Mid-infrared single-photon counting. Opt. Lett., 2006, 31: 1094-1096.

[19] Q. Zhou, K. Huang, H. Pan, E. Wu, H. Zeng. Ultrasensitive mid-infrared up-conversion imaging at few-photon level. Appl. Phys. Lett., 2013, 102: 241110.

[20] M. Mancinelli, A. Trenti, S. Piccione, G. Fontana, J. S. Dam, P. Tidemand-Lichtenberg, C. Pedersen, L. Pavesi. Mid-infrared coincidence measurements on twin photons at room temperature. Nat. Commun., 2017, 8: 15184.

[21] M. Mrejen, Y. Erlich, A. Levanon, H. Suchowski. Multicolor time-resolved upconversion imaging by adiabatic sum frequency conversion. Laser Photon. Rev., 2020, 14: 2000040.

[22] T. W. Neely, L. Nugent-Glandorf, F. Adler, S. A. Diddams. Broadband mid-infrared frequency upconversion and spectroscopy with an aperiodically poled LiNbO₃ waveguide. Opt. Lett., 2012, 37: 4332-4334.

[23] L. Lehmann, L. Grossard, L. Delage, F. Reynaud, M. Chauvet, F. Bassignot. Single photon MIR upconversion detector at room temperature with a PPLN ridge waveguide. Opt. Express, 2019, 27: 19233-19241.

[24] X. Liu, B. Kuyken, G. Roelkens, R. Baets, R. M. Osgood, W. M. J. Green. Bridging the mid-infrared-to-telecom gap with silicon nanophotonic spectral translation. Nat. Photonics, 2012, 6: 667-671.

[25] Q. Zheng, H. Zhu, S.-C. Chen, C. Tang, E. Ma, X. Chen. Frequency-upconverted stimulated emission by simultaneous five-photon absorption. Nat. Photonics, 2013, 7: 234-239.

[26] D. A. Fishman, C. M. Cirloganu, S. Webster, L. A. Padilha, M. Monroe, D. J. Hagan, E. W. V. Stryland. Sensitive mid-infrared detection in wide-bandgap semiconductors using extreme non-degenerate two-photon absorption. Nat. Photonics, 2011, 5: 561-565.

[27] J. S. Dam, P. Tidemand-Lichtenberg, C. Pedersen. Room-temperature mid-infrared single-photon spectral imaging. Nat. Photonics, 2012, 6: 788-793.

[28] D. Knez, A. M. Hanninen, R. C. Prince, E. O. Potma, D. A. Fishman. Infrared chemical imaging through non-degenerate two-photon absorption in silicon-based cameras. Light Sci. Appl., 2020, 9: 125.

[29] R. Demur, A. Grisard, L. Morvan, E. Lallier, N. Treps, C. Fabre. High sensitivity narrowband wavelength mid-infrared detection at room temperature. Opt. Lett., 2017, 42: 2006-2009.

[30] J. S. Pelc, L. Ma, C. R. Phillips, Q. Zhang, C. Langrock, O. Slattery, X. Tang, M. M. Fejer. Long-wavelength-pumped upconversion single-photon detector at 1550 nm: performance and noise analysis. Opt. Express, 2011, 19: 21445-21456.

[31] K. Huang, X. Gu, H. Pan, E. Wu, H. Zeng. Few-photon-level two-dimensional infrared imaging by coincidence frequency upconversion. Appl. Phys. Lett., 2012, 100: 151102.

[32] K. Huang, X. R. Gu, H. F. Pan, E. Wu, H. P. Zeng. Synchronized fiber lasers for efficient coincidence single-photon frequency upconversion. IEEE J. Sel. Top. Quantum Electron., 2012, 18: 562-566.

[33] T. Xiang, Q.-C. Sun, Y. Li, Y. Zheng, X. Chen. Single-photon frequency conversion via cascaded quadratic nonlinear processes. Phys. Rev. A, 2018, 97: 063810.

[34] R. L. Pedersen, L. Høgstedt, A. Barh, L. Meng, P. Tidemand-Lichtenberg. Characterization of the NEP of mid-infrared upconversion detectors. IEEE Photon. Technol. Lett., 2019, 31: 681-684.

[35] E. Pomarico, B. Sanguinetti, R. Thew, H. Zbinden. Room temperature photon number resolving detector for infared wavelengths. Opt. Express, 2010, 18: 10750-10759.

[36] K. Huang, X. Gu, M. Ren, Y. Jian, H. Pan, G. Wu, E. Wu, H. Zeng. Photon-number-resolving detection at 1040 μm coincidence frequency upconversion. Opt. Lett., 2011, 36: 1722-1724.

[37] R. A. McCracken, F. Graffitti, A. Fedrizzi. Numerical investigation of mid-infrared single-photon generation. J. Opt. Soc. Am. B, 2018, 35: C38-C48.

[38] Y. M. Sua, H. Fan, A. Shahverdi, J.-Y. Chen, Y.-P. Huang. Direct generation and detection of quantum correlated photons with 3.2  μm wavelength spacing. Sci. Rep., 2017, 7: 17494.

[39] S. Tanzilli, W. Tittel, M. Halder, O. Alibart, P. Baldi, N. Gisin, H. Zbinden. A photonic quantum information interface. Nature, 2005, 437: 116-120.

[40] H. Takesue. Single-photon frequency down-conversion experiment. Phys. Rev. A, 2010, 82: 013833.

[41] K. Huang, X. Gu, Q. Zhou, H. Pan, E. Wu, H. Zeng. Efficient generation of mid-infrared photons at 3.16  μm by coincidence frequency downconversion. Laser Phys., 2013, 23: 045401.

[42] J. Zeng, B. Li, Q. Hao, M. Yan, K. Huang, H. Zeng. Passively synchronized dual-color mode-locked fiber lasers based on nonlinear amplifying loop mirrors. Opt. Lett., 2019, 44: 5061-5064.

[43] W. Kang, B. Li, Y. Liang, Q. Hao, M. Yan, K. Huang, H. Zeng. Coincidence-pumping upconversion detector based on passively synchronized fiber laser system. IEEE Photon. Technol. Lett., 2020, 32: 184-187.

[44] L. Meng, L. Høgstedt, P. Tidemand-Lichtenberg, C. Pedersen, P. John Rodrigo. Enhancing the detectivity of an upconversion single-photon detector by spatial filtering of upconverted parametric fluorescence. Opt. Express, 2018, 26: 24712-24722.

[45] M. Widarsson, M. Henriksson, P. Mutter, C. Canalias, V. Pasiskevicius, F. Laurell. High resolution and sensitivity up-conversion mid-infrared photon-counting LIDAR. Appl. Opt., 2020, 59: 2365-2369.

[46] S. Wolf, T. Trendle, J. Kiessling, J. Herbst, K. Buse, F. Kühnemann. Self-gated mid-infrared short pulse upconversion detection for gas sensing. Opt. Express, 2017, 25: 24459-24468.

[47] Z. Bao, Y. Liang, Z. Wang, Z. Li, E. Wu, G. Wu, H. Zeng. Laser ranging at few-photon level by photon-number-resolving detection. Appl. Opt., 2014, 53: 3908-3912.

[48] C.-Q. Hu, Z.-Q. Yan, J. Gao, Z.-Q. Jiao, Z.-M. Li, W.-G. Shen, Y. Chen, R.-J. Ren, L.-F. Qiao, A.-L. Yang, H. Tang, X.-M. Jin. Transmission of photonic polarization states through 55-m water: towards air-to-sea quantum communication. Photon. Res., 2019, 7: A40-A44.