far-infrared

Using the characteristic of refractive index are smaller than 1 in the reststrahlen band,we can produce photonic crystal having forbidden band in the middle infrared and far infrared.

由此可知利用材料在剩余射线内折射率小于1，们可以制备出中红外区和远红外区存在禁光子晶。

It also emits natural phytocide to keep air fresh, and keep people's mind clear, and emit the far infrared ray to improve the blood circulation to relieve the fatigue.

同时其释放远红外线能促进血液循环，消除疲劳。