I'm no expert or authority at all -- just your garden-variety reader long fascinated by abnormal psychology, among other related subjects. Erotomania has always been of particular interest, since I had my own real-life brush with it (no details here, as she is still very much alive and probably active on the 'Net; let's just say I'm much too familiar with what you're talking about).
If that's what's motivating your stalker, well, frankly, the odds are very slim she will
ever stop -- unless she finds another victim to replace you with (and then, thank God, you will cease to exist in her mind). Police -- and restraining orders -- seem like the obvious solution, but sometimes do more inadvertent harm than good.
The best ("best" meaning most comprehensive) account of erotomania I've ever read is "I Know You Really Love Me: A Psychiatrist's Journal of Erotomania, Stalking, and Obsessive Love" --
http://www.amazon.com/Know-You-Really-Love-Psychiatrists/dp/0028616650 . You might want to pick up a copy just to see if any of the common characteristics stands out in your stalker's behavior; it was written by a (female) psychiatrist who, through no fault of her own, became the object of obsession by a (female) patient. It's extremely unsettling, but it may give you some insight, and some ideas on where to go from here.
I don't agree with the poster who told you to ignore it either. At the very least, your reputation is at stake; at the very worst, your life is at stake.
I wish you the very best of luck with this. It's a matter not to be taken lightly at all.