提出了一种改进的非线性元件实现线性放大(Linear Amplifier Using Non-linear Components,LINC)理论,将幅度和相位均有变化的射频信号分离成包络信号和恒包络角调信号,将包络信号分两路反相调制到后者的相位中,对两路调制后的恒包络信...提出了一种改进的非线性元件实现线性放大(Linear Amplifier Using Non-linear Components,LINC)理论,将幅度和相位均有变化的射频信号分离成包络信号和恒包络角调信号,将包络信号分两路反相调制到后者的相位中,对两路调制后的恒包络信号进行变频放大,通过减法电路得到放大后的上变频输入射频信号.因为恒幅信号可以在放大器的非线性区放大而不失真,提高了整体效率高.推导出其电压增益为KG/Em,并对不同频率和幅度进行了仿真,仿真结果表明实现了理论分析预期的放大效果.展开更多
Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.Howe...Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.展开更多
文摘提出了一种改进的非线性元件实现线性放大(Linear Amplifier Using Non-linear Components,LINC)理论,将幅度和相位均有变化的射频信号分离成包络信号和恒包络角调信号,将包络信号分两路反相调制到后者的相位中,对两路调制后的恒包络信号进行变频放大,通过减法电路得到放大后的上变频输入射频信号.因为恒幅信号可以在放大器的非线性区放大而不失真,提高了整体效率高.推导出其电压增益为KG/Em,并对不同频率和幅度进行了仿真,仿真结果表明实现了理论分析预期的放大效果.
文摘Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.
