transistor

Yes, but by what?..all this stuff about optical processing doesn't really address I/O and interfacing issues.

Well, yes and no...

Better is pretty wide open.

"A sports car is better and faster transportation"

Unless of course you are trying to transport 9 yards of concrete!

Transistor is pretty open also.

Ok, now that all the smart alecs have weighed in...

You might try a FET of one variety or another. But as has been mentioned, this is going to depend on the application. Do you have a schematic of the present circuit that you can post?

It may sound a little smart alec at times when the answers are as short and open as the question but it is import for people to learn to ask answerable questions. Maybe do enough research to get a basic understanding. I have watched many discussions here go on and on in 20 different directions because everybody is making assumptions about the original post.

Would be helpful if you`d explain which operation you have in mind and what is "fast" for you.

You can use transistors par example not only as transistors but as tunneling devices - then tey do not operate as "normal" transistors but are - logically - still ones but are extremely fast for generating pulses.

But as long as we don`t know which application you really mean a qualified answer for your demands is nearly impossible.