Can someone please tell me what I need to get a lighting setup similar to this?
The centre is illuminated and it subtly gets darker around the edges.
Put one light behind the subject pointing at the background. Light naturally becomes less intense, the further you are away from the light source.
You can further manipulate the falloff with modifiers:
Unless your equipment has a way to zoom, the snoot is probably the best option. You can easily and quickly make it yourself by just wrapping some flexible material around the light source to form a tube that limits the cone of light.
1) A difuse light. You can see that this is so by the shadow. (My gess a 2x2 feet softbox)
2) A grid or a simply cone (or a box) of dark paper (snoot). You can see that is lighting very specific in front of the guy when he goes back.
3) Try putting it just over the guy and start moving it to the camera.
4) I have the feeling it is not too close to your subject, because you do not see much diference between the table and the guy.
If you want an even stronger effect, take two lights with directivity (not wide-angle flood) and place them well off to your right and left, aimed at the subject. What light doesn't hit the subject will travel out of frame, leaving the background dark. Sort of like "dark field" illumination in microscopy.
This can produce strong highlights on the subject, though.
Depending on the situation and degree of light falloff you want, you may be able to get an effect similar to this without manipulating the lighting at all.
To do it, choose a fast (f/1.4, or even better, f/1.2) lens, and shoot wide open. This tends to be particularly true with shorter lenses, such as a 24mm f/1.4, which can show it to an almost alarming degree.
Also note that this is generally seen as a defect in a lens' design, so if you want it, you might want to look at older, less-expensive lenses. These also tend to be less sharp, but if you're interested primarily in portraits, that's usually not a big problem.
To there appear to be three light sources. Two are diffuse sources behind and above the camera, one on the left and one on the right. These produce:
The third light source is behind the subject and illuminating the background as others have mentioned. It appears to have a diffuser. The background cut off to vertical at camera right could be due either to the shape of the diffuser or digital manipulation in the pixel pipeline.