[1] [1] Schawlow A L, Townes C H. Infraredand optical masers [J]. Phys. Rev., 1958, 112:1940～1949

[2] [2] Kolobov M I, Davidovich L, Giacobino E et al. Role of pumping statistics anddynamics of atomic polarization in quantum fluctuation of laser sources [J]. Phys. Rev. A,1993, 47:1431～1446

[3] [3] Louisell W. Quantum Statistical Properties ofRadiation [M]. New York: Wiley, 1973.

[4] [4] Carmichael H J. Quantum fluctuations in absorptive bistability without adiabaticelimination [J]. Phys. Rev. A,1986, 33: 3262～3269;Reid M D. Quantum theory of opticalbistability without adiabatic elimination [J]. Phys.Rev. A, 1988, 37:4792～4818

[5] [5] Agarwal G S. Inhibition of spontaneous emission noise in lasers without inversion[J]. Phys. Rev. Lett., 1991, 67:980～982

[6] [6] Fleischhauer M, Rathe U, Scully M O. Nonadiabatic linewidth of Λ-type noninversionlaser [J]. Phys. Rev. A,1994, 50:1748～1754

[7] [7] Harris S E. Lasers without inversion: interference of lifetime-broadened resonances[J]. Phys. Rev. Lett., 1989, 62:1033～1036;Scully M O, Zhu S Y, Gavrielides A.Degenerate quantum-beat laser: lasing without inversion and inversion without lasing [J].Phys. Rev. Lett., 1989, 62: 2813～2816;Imamoglu A, Field J E, Harris S E. Lasers withoutinversion: a closed lifetime broadened system [J]. Phys. Rev. Lett., 1991, 66:1154～1156

[8] [8] Nottelmann A, Peters C, Lange W. Inversion amplification of picosecond pulses dueto Zeeman coherence [J]. Phys.Rev. Lett., 1993, 70: 1783～1786;Fry E, et al. Atomiccoherence effects within the sodium line: lasing withoutinversion via populations [J].Phys. Rev. Lett., 1993, 70: 3235～3238;van der Veer W E, et al. Experimentaldemonstration of light amplification without population inversion [J]. Phys. Rev. Lett.,1993, 70:3243～3246

[9] [9] Sargent M , Scully M O, Lamb W E. Laser Physics [M]. Addison-Wesley, 1974.