A new nano-camera invented by American scientists can help people grow eyes behind their heads

    Many of us may have imagined as children that we could grow a pair of eyes behind our heads, like Superman, and see what we shouldn't be able to see behind us. Now, thanks to a new type of nano-camera, Superman-like vision may not be far away. As a child, Ramesh Raskar also imagined growing eyes behind his head. Although this strange idea has long since disappeared, Raskar has been looking for ways to broaden people's horizons.

Nano-cameras give people eyes behind their heads

    Today, Raskar, director of the Camera Culture Research Group and associate professor of media arts and sciences at the MIT Media Lab, has finally realized his childhood fantasy. He invented a nano-camera that can capture images at the speed of light and a DIY medical imaging tool. "This is not only a new vision, but also a superhuman vision," Raskar said.

    In order to avoid being limited in their thinking, the research team continuously improved their original goals and used the cross-integration of knowledge from multiple fields. In order to create a nano camera that reduces motion blur in imaging, they even studied the propagation of light and worked hard to cross-integrate various possibilities.

    The inspiration for this nano camera comes from the high-speed photography work "Standstill Time" taken by MIT professor Harold Edgerton in 1964 (which captured the moment a bullet pierced an apple). The speed of this nano camera is millions of times faster than the high-speed imaging equipment Edgerton used back then. This new femtosecond imaging technology (1 femtosecond is equal to one quadrillionth of a second) has created a new record in the field of "capturing" light.

    The research team used ultrashort laser pulses instead of bullets to "shoot" through a Coke bottle. A special camera with 500 trillion frames per second recorded the moment the bottle was pierced in a double exposure time of two trillionths of a second, capturing the image of light in motion.

    In the test, in order to capture the target object hidden behind the wall, the researchers operated the camera to emit ultrashort laser pulses toward another wall near the target. The laser pulses will scatter after hitting the wall, and a large number of scattered photons will bounce to different parts of the target to produce secondary scattering. Finally, the camera will capture and analyze the photons that return to the lens after multiple scattering, and after calculation, construct the target image that should not have been captured. This "no blind spot" camera may be used for detection in dangerous environments in the future.

    Raskar's goal of "making the invisible visible" has extended to the human body. The research team has now developed a mobile phone accessory that can take pictures with the help of the eyes. It is inexpensive and can be used for patient management and disease diagnosis. In the future, femtosecond imaging technology may also be applied to instantaneous medical imaging, greatly shortening the imaging time. In addition to high-speed photography, femtosecond imaging technology will also be used in some unexpected fields, such as capturing tiny particles that scatter light in the gas, and creating visual images that can replace the sense of smell after analysis.

    Raskar predicts that new imaging technologies will become a catalyst for changing all aspects of human life. They will not only record what we see as traditionally, but will also help people gain superhuman vision.