Researchers have used the centuries-old idea of pinhole imaging to create a high-performance mid-infrared imaging system without lenses. The new camera can capture extremely clear pictures over a large range of distances and in low light, making it useful for situations that are challenging for traditional cameras.
Hmm, so if I understand the paper (which I might not), the lens is created by one laser beam, and then light from the sample causes a two photon effect in the lens area. Since two photon effects continue propagation, it’s in effect a pinhole which can be used for imaging. This seems like quite an elegant experiment.