Infrared imaging is a crucial technique in a multitude of applications, including night vision, autonomous vehicle navigation, optical tomography, and food quality control. Conventional infrared imaging technologies, however, require the use of materials such as narrow bandgap semiconductors, which are sensitive to thermal noise and often require cryogenic cooling. We demonstrate a compact all-optical alternative to perform infrared imaging in a metasurface composed of GaAs semiconductor nanoantennas, using a nonlinear wave-mixing process. We experimentally show the upconversion of short-wave infrared wavelengths via the coherent parametric process of sum-frequency generation. In this process, an infrared image of a target is mixed inside the metasurface with a strong pump beam, translating the image from the infrared to the visible in a nanoscale ultrathin imaging device. Our results open up new opportunities for the development of compact infrared imaging devices with applications in infrared vision and life sciences.

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Nonlinear necklace and azimuthon beams were experimentally generated in a self-focusing bulk photorefractive nonlinear medium (crystal SBN:60) using a frequency-doubled Nd:YVO 4 laser at 532 nm. The parallel optical waveguides induced by such a beam were probed by near-infrared signal beams emitted by a Ti:Sapphire laser. The quality and time stability of the guided sub-beams at the exit of the crystal were investigated. In view of the waveguides' ordering along a ring, the best matching probe beams were found to be singly or doubly charged optical vortex bright rings. The results indicate the feasibility of parallel all-optical guiding of optical signals at wavelengths, for which the nonlinear medium is not photosensitive.

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Many applications ranging from nonlinear optics to material processing would benefit from pulsed ultrashort (quasi-)non-diffracting Gauss-Bessel beams (GBBs). Here we demonstrate a straightforward yet efficient method for generating such zeroth- and first-order GBBs using a single reflective spatial light modulator. Even in the sub-8-fs range there are no noticeable consequences for the measured pulse duration. The only effect is a weak "coloring" of the outer-lying satellite rings of the beams due to the spectrum spanning over more than 300 nm. The obtained beams have diffraction half-angles below 40 μrad and reach propagation distances in excess of 1.5 m.