温度对液晶填充光子晶体光纤传输特性的影响

利用液晶的折射率是温度和波长函数的特性,在光子晶体光纤(PCF)芯区的空气柱中填充向列相液晶,通过改变温度来改变液晶的折射率,构成了一种温度凋制光子晶体光纤.用阶跃有效折射率模型研究了温度对这种光子晶体光纤在不同光波长时传输特性的影响,并进行了数值计算.结果表明液晶填充使光子晶体光纤的色散减小,由于折射率对温度和波长变化敏感,改变温度可以使光纤在长波长区域出现单模传输,在短波长时不会出现单模传输,即使包层相对孔径很小也不会出现无截止单模传输.温度升高使光纤的色散值增大,零色散波长向短波长方向移动.这些特性对温度调制光子晶体光纤器件的设计和应用具有一定的参考意义.

Effect of Temperature on Transmission Properties in Photonic Crystal Fibers Infiltrated With Liquid Crystal

Thermally tunable photonic crystal fibers (PCF) are proposed by filling the air hole of PCF core with nematic liquid crystal (LC) and using the LC refractive index change with temperature and wavelength, due to index sensitive to temperature and wavelength. The effect of temperature on PCF transmission properties is studied by the step effective index model and numerical calculation. The results show that dispersion decreases in the PCF infiltrated with liquid crystals, and the PCF appears as single-mode transmission in long wavelength but not in short wavelength, and non-cutoff-wavelength single-mode transmission does not appear even if relative hole diameters in cladding are very small. The dispersion increases and zero dispersion wavelengths shift towards short wavelengths when temperature increases in the PCF. The properties are valuable for design and application of temperature tunable PCF device.