I am a fellow of Wolfson College which is a jolly nice place for graduate students (Masters and PhDs) and I strongly recommend when you are putting down a College preference when applying!
First of all, read the Lab web pages on Graduate Degree applications - note that we have a Masters programme, which makes a nice lead in to the 3 year PhD, especially if you are not certain what you want to work on, or that you want to work on it that long.
Next, have you looked at the Prospectus?
Now check my graduate management skills and sources of ideas before xkcd.
Now, have you looked at the srg and netos research web pages? I leave it as an exercise for you to find those:)
If you have done all of that, and want to apply, but want to contact us first, then that is fine. We want to see a two page proposal, Here is a Daft Example (I leave it as an exercise for you to see why:-) or else take a look at my conjectures and ideas for gadgets for more ideas of what I do and do NOT do (e.g. QoS:).
The purposes of the two page proposal is to provide us with information about what kind of problem you think is worth tackling, why, and how you might start going about solving it through research (not through mere development). This will allow us to matchmake between your application, and appropriate supervisor, and possibly see if your proposal fits in with existing projects, which would mean you would be able to work in a collaboration with other researchers, which is all part of the experience. The proposal is not a binding one - indeed, many people change 1 or 2 times in the first year before settling on the final thesis topic (see the information above for more about that). If you have published work, by all means send us this with CV info, preferably just as a URL to a web page with the information on it rather than a bunch of attachments (if you do send attachments, text, html and pdf are preferred).
In the last 3 years, I personally have received > 1200 email applications, i.e. roughly one per day. The group has around 30 students, in other words around 10 a year arrive and 10 depart. Go figure the odds.
We are also part of the photonics see also DTC which represents another (funded) opportunity if you have an interest in that angle.
Remember, we don't handle the actual formal application, and until you send in a formal application, we can only informally discuss hypothetical matters.
If that isn't clear, then take a look here