If you don't use the DVD drive much, you might just want to replace it with a hard drive caddy to allow you to add a 2nd hard drive to your laptop (if one is available for your model laptop).
Otherwise, you can probably find a cheap replacement on eBay, though you may have to replace the outside bezel with the one on your broken drive for it to match your laptop. If you haven't removed a DVD drive (you'll have to remove the body of the old drive) from your laptop before, you can probably find instructions via Google or even a Youtube video.