Graphene can be used to enhance photonics, as a detector for light, an optoelectronic transceiver, or as part of high-resolution imaging systems.
A surprising application of graphene is its use in photodetectors. Light detection capabilities of graphene are inherently limited because a single sheet of the material absorbs only ~2.3% of light across the visible part of the spectrum. Such high transparency is desired for applications such as transparent conductors, however detecting light requires strong absorption. Nevertheless, the frequency-independent absorption of graphene coupled with extremely high carrier mobility peaked the interest of optics researchers, who found that interfacing graphene with strong light-absorbing materials can result in excellent practical photodetectors that surpass the capabilities of competing materials.
A particularly interesting direction of research is the use of hybrid graphene-quantum dot photodetectors as broadband image sensors for CMOS cameras. These fab-compatible devices have very high responsivity, on the order of 107 A/W and operate in both the visible and short-wave infrared parts of the spectrum (300-2,000 nm). The response times are fast enough (0.1-1 ms) for use in infrared cameras. What is perhaps the most interesting about this device is that it is a CMOS integrated circuit, similar to those used for commercial image sensors in digital cameras, commonly used in smartphones.