Studying invisibility cloaks with the fastest camera ever created
You can start wandering how fast a camera can be. The answer in linked with what do you mean by camera. The best `streak cameras` can shoot in about 100 femtoseconds which basically means a quadrillionth of a second.
The main characteristic of an optoelectronic streak camera is the fact that it can scope rapid variations of the intensity of light by just wide-ranging the pulse. In other words this means that the electrons produced by that light pulse are scoped across a detector. This is a way to record spatially a temporal variation by just trying different pixels. So, the researchers tried to start the standard streak camera with the narrow entrance aperture wide open. This was what made possible for them the access to an entire three-dimensional scene contained into two space dimensions and one time dimension. Even though this is quite simple, it generates a tremendous decoding problem at the detector.
From all this mess of light they were able to create an image by using a beam splitter in order to alter a part of the image to a 2D detector display. At the same time, the rest of the image was sent to a digital micromirror device that encrypts an arbitrary spatial pattern onto that arm of the beam. This technique was named compressed ultrafast photography ( CUP) because in the process is required a computational method in order to regenerate the image.
This ultrafast camera was used to reflect four fundamental physical processes: laser pulse reflection, refraction, photon diffraction across two media and a faster than light propagation event. Even though those sound like some kind of SF movie, there are some videos that prove the light was captured red-handed in the act.
Some may think that this imagination of a faster than light phenomenon can make easy to watch the light dealing with invisibility cloaks. Reasearchers do not state this, but the metamaterial behavioral can be considered the next step to be made in this field.
There are some that state the fact that slow-motion imaging is a must have in order to improve our knowledge of the natural world. So, the researchers of the camera described above considered the fact that it can be attached to powerful microscopes and telescopes. These devices will combine the sharp spatial resolution of the Hubble and the temporal resolution of the CUP camera.
Also, it is good to mention that the researchers added a fourth dimension to their camera: the wavelength. This requires a dichroic mirror to further separate the light. Before of the apparition of the CUP camera, the fluctuations in wavelength were almost impossible to measure.