【摘要】 提出了利用周期性热及电场诱导D型光纤光栅的二次非线性级联 (χ(2 ) ∶χ(2 ) ) ,实现在波分复用网中波长转换的方法 ,并进行了理论分析 .推导出 χ(2 ) ∶χ(2 ) 的耦合模方程 ,得出了小信号条件下转换产生光波的场强振幅和功率 ,以及转换效率 η的解析式 ,该式与数值计算相吻合 .解析式和数值结果都表明 ,在近似满足相位匹配条件下 ,η与抽运光功率平方、光栅总长度L和二次非线性系数d的四次方分别成对数关系 .计算结果表明 ,这种光纤光栅的波长转换效率 η和转换带宽Δλ分别可达 - 17dB和 12 0nm ;随着L的增加 ,η迅速地增加 ,但Δλ却很快减小 .模拟计算和理论分析结果都表明 ,χ(2 ) ∶χ(2 ) 级联过程不同于准相位匹配差频产生过程 .更多还原

【Abstract】 A novel wavelength conversion method for wavelength division multiplexing(WDM) nets by use of cascaded second\|order nonlinearities (χ (2) ∶χ (2) ) in D\|fiber grating after periodically thermal/electric\|field poling is proposed,and is theoretically analyzed for the first time.The coupled mode equations of the χ (2) ∶χ (2) nonlinearities are derived,and the analytic expressions for the electric\|field intensity amplitude of the conversion light waves and conversion efficiency η are obtained under the small signal condition,which are well consistent with numerical calculations.Both analytic expressions and numerical results show that,under the suitabl phase\|matching condition,η is proportional to the logarithm of the square of pump light power,and the 4th power of the grating length L & second\|order nonlinearity d.The calculated results also show that the wavelength conversion efficiency η and conversion bandwidth Δλ of over-17?dB and 120?nm respectively can be reached with this fiber grating.With the increase of L,η increases quickly white Δλ decreases quickly.The results of simulated calculation and theoretical analysis show that the cascaded χ (2) ∶χ (2) process is different from that of quasi\|phases\|matched difference\|frequency\|generation.更多还原