Potonic crystal fiber is widely applied in the active and passive devices of the fiber communication systems and the photoelectric signal detection. The air hole refractive index is analysed by Edlen formula. And the distribution of the quartz thermal stress and the refractive index is analysed by the heat conduction model in the solid-core photonic crystal fibers in the temperature field. The fluctuation of the pulse phase and mode birefringence in the photonic crystal fibers is also discussed. Optical pulse in the photonic crystal fibers is less sensitive to the tomperature than in general single-mode fibers. So it is beneficial in the active and passive devices in the photoelectric signal detection.