The approach to the camera is particularly important. Other techniques for capturing very fast events usually require many, many exposures to see anything; the streak camera only needs one. On top of the simplicity, this lets you capture events that won't repeat in the exact same way, such as the laser pulses.

This could provide new insights into light, of course, but the scientists are ultimately interested in biology. Their system is fast enough to track neurons as they fire, and map brain activity in real time. You could track even the smallest details, which could improve our understandings of both the mind and brain-related diseases.