 This work is about a new kind of photo detector using the property of graphene transistor. So graphene is one single atomic layer thick of carbon. Its electroconductivity is very sensitive to electric field to act on graphene. In other words, if you apply electric field, you can change the amount of charge carriers in graphene and that changes connectivity or resistance. When light comes in, create carriers in this underlying substrate, in this case silicon carbide, it actually modulates the electric field and acts on graphene because we already have a background electric field by a voltage applied in the back. So we call this a photo transistor or photo-actuated or modulated transistor. The nice thing about our device is we apply laser enumeration out of the graphene area. We are still able to observe photo response. And for typical devices like already demonstrated so far, they observe photo response in a very limited area. That's why this is called a non-local or large area photo detection. And that's actually quite useful because often you may not know exactly where light comes from or where it will hit, but you still would get a response. So this is a complementary to a lot of other photo detectors people already develop including based on graphene, but you require light to hit right on graphene or nearby and this one does not have to. So it's a new kind of a principle, new kind of device.