Definitely! "As requested," as well as "As per your request," "per your request," "per your request", etc. However, as Brad pointed out, "as requested" as well as all of the examples I and 博迈克 (As promised) gave are all formal. They are to be used only in formal and business writing only. Using them in colloquial (everyday) conversation is awkward and non-fluid.

I agree with Brad's answer below. As requested = As you requested. A similar phrase in business writing is "As promised," which means "As I promised."

Of course. Example: "As requested, I have attached the file for your review." This is more typical in business writing, not in normal English speech, but it's very common and correct.

SGD