[1] DANION G, HAMEL C, FREIN L, et al. Dual frequency laser with two continuously and widely tunable frequencies for optical referencing of GHz to THz beatnotes［J］. Optics Express, 2014, 22(15): 17673-17678.
[2] PILLET G, MORVAN L, BRUNEL M, et al. Dual-frequency laser at 1.5 μm for optical distribution and generation of high-purity microwave signals［J］. Journal of Lightwave Technology, 2008, 26(15): 2764-2773.
[3] ROLLAND A, FREIN L, VALLET M, et al. 40-GHz photonic synthesizer using a dual-polarization microlaser［J］. IEEE Photonics Technology Letters, 2010, 22: 1738-1740.
[4] ROLLAND A, BRUNEL M, LOAS G, et al. Beat note stabilization of a 10-60 GHz dual-polarization microlaser through optical down conversion［J］. Optics Express, 2011, 19(5): 4399-4404.
[5] QIAO Y F, ZHENG S L, CHI H, et al. Electro-optically tunable microwave source based on composite-cavity microchip laser［J］. Optics Express, 2012, 20(27): 29090-29095.
[6] PILLET G, MORVAN L, MENAGER L, et al. Dual-frequency laser phase locked at 100 GHz［J］. Journal of Lightwave Technology, 2014, 32(20): 3824-3830.
[7] TONDA G S, DOLFI D, MONSTERLEET A, et al. Optical signal processing in radar systems［J］. IEEE Transactions on Microwave Theory and Techniques, 2006, 54(2): 847-853.
[8] CHENG C H, LEE C W, LIN T W, et al. Dual-frequency laser Doppler velocimeter for speckle noise reduction and coherence enhancement［J］. Optics Express, 2012, 20(18): 20255-20265.
[9] ZHENG Z, ZHAO C M, ZHANG H, et al. Phase noise reduction by using dual-frequency laser in coherent detection［J］. Optics & Laser Technology, 2016, 80: 169-175.
[10] CHEN J, ZHU H, XIA W, et al. Self-mixing birefringent dual-frequency laser Doppler velocimeter［J］. Optics Express, 2017, 25(2): 560-572.
[11] HUANG Y J, TZENG Y S, TANG C Y, et al. Efficient high-power terahertz beating in a dual-wavelength synchronously mode-locked laser with dual gain media［J］. Optics Letters, 2014, 39(6): 1477-1480.
[12] ROLLAND A, DUCOUMAU G, DANION G, et al. Narrow linewidth tunable terahertz radiation by photomixing without servo-locking［J］. IEEE Transactions on Terahertz Science and Technology, 2014, 4(2): 260-266.
[13] ZHAO P, RAGAM S, DING Y J, et al. Power scalability and frequency agility of compact terahertz source based on frequency mixing from solid-state lasers［J］. Applied Physics Letters,2011, 98(13): 131106.
[14] ZHAO P, RAGAM S, DING Y J, et al. Investigation of terahertz generation from passively Q-switched dual-frequency laser pulses［J］. Optics Letters, 2011, 36(24): 4818-4820.
[15] CHO C Y, HUANG T L, WEN S M, et al. Nd∶ YLF laser at cryogenic temperature with orthogonally polarized simultaneous emission at 1047 nm and 1053 nm［J］. Optics Express,2014, 22(21): 25318-25323.
[16] YE P, ZHU S, LI Z, et al. Passively Q-switched dual-wavelength green laser with an Yb: YAG/Cr4+: YAG/YAG composite crystal［J］. Optics Express, 2017, 25(5): 5179-5185.
[17] MCKAY A, DAWES J M. Tunable terahertz signals using a helicoidally polarized ceramic microchip laser［J］. Photonics Technology Letters , 2009, 21(7): 480-482.
[18] HU M, AN R D, ZHANG H, et al. Experimental investigation of a novel microchip laser producing synchronized dual-frequency laser pulse with an 85 GHz interval［J］. Laser Physics Letters, 2012, 10(1): 015801.
[19] HUANG Y J, CHO H H, SU K W, et al. Exploring a diffusion-bonded Nd∶YVO4/Nd∶GdVO4 crystal for generating an efficient diode-end-pumped dual-spectral-band laser［C］. Advanced Solid State Lasers. 2015: ATu1A.7.
[20] DANION G, ROLLAND A, BONDU F, et al. Investigation of the coupling between pump amplitude noise and differential phase noise in an Er, Yb: glass two-polarization dual-frequency solid-state laser［J］. Journal of the Optical Society of America B, 2016, 33(4): 589-593.
[22] SATO Y, TAIRA T. Temperature dependencies of stimulated emission cross section for Nd-doped solid-state laser materials［J］. Optical Materials Express, 2012, 2(8): 1076-1087.
