光子晶体光纤中反斯托克斯效应的实验研究

Experimental investigation of anti-Stokes effect in photonic crystal fiber

在对自行设计的光纤进行实验研究的过程中,通过逐渐增加泵浦脉冲的中心波长λ_0发现随着λ_0逐渐接近零色散波长λ_D,在一系列非线性效应的作用下泵谱脉冲的频谱逐渐展宽,同时其转化效率也逐渐增加,在短波段的反斯托克斯波的强度也逐渐增加。尤其当λ_0等于λ_D时,反斯托克斯波达到最强,说明此时相位匹配的很好,致使四波混频效应最为显著。而当λ_0逐渐远离λ_D时,在频谱宽度逐渐减小的同时,泵谱转化效率也逐渐降低。当λ_0为860nm时,反斯托克斯波几乎消失,这充分说明泵谱中心波长λ_D在频率转换过程中的显著影响。

In the process of experiment investigation on photonic crystal fiber fabricated by ourselves, by increasing the central wavelength of pump pulse λ0 gradually, the frequency spectrum of pump pulse is widening gradually with λ0 approaching to λD, at the same time, and the intensity of anti-Stokes wave is increasing gradually with the transform-efficiency being enhanced. Especially while λ0 equals to λD, the intensity of anti-Stokes wave reaches to the highest level, showing that the phase being well matching and that the four-wave-mixing being very remarkable. However, while λ0 being away from λD gradually, the transform-efficiency of pump also is reducing gradually as the width of frequency spectrum decreases. While λ0 is 860 nm, the anti-Stokes wave disappears nearly, showing the remarkable influence of the pump central wavelength λ0 on the process of frequency conversion.