哪里能买到开关速度在ns量级的光开关产品

现在有这样的高速光开关的成熟产品吗？
目前能卖得最快光开关的开光速度能达到多少？？

In which applciation, you need so high speed switch?
To my knowledge,in current system, there is no place for this high speed switch.
If you are talking about the product, not some fancy experiments in some labs, us switch may be the fast you can expect.  

用特种材料二氧化钒做成的热光开光就可以

好像目前一些半导体光开关的开关速度能达到ns量级，但是哪里有提供呢？

热光开关的性能如何？