Scientists bend 'Friggin' laser beam to create detailed images of this cat

Jennifer Ouellette – August 15, 2022 at 8:41 pm UTC

PF Silva & SR Muniz, 2022

Every cat owner knows how their feline companions are Chase a tiny spot of light from a simple laser pointer. Now, Brazilian physicists have figured out how to capture and bend laser light into complex shapes, resulting in the impressively realistic images of cats pictured above. Among other potential applications, their method (described in a recent paper on Physics arXiv) may prove useful in building better optical traps to create clouds of ultracold atoms for various quantum experiments .

The ability to generate and precisely control the shape of a high-fidelity laser beam is important for many studies Fields are both critical, according to co-authors Pedro Silva and Sergio Muniz of the University of São Paulo, Industry and Industry. They divide most wavefront engineering methods into two basic categories.

The first category includes digital micromirrors such as DMD ) and acousto-optic modulators (AOMs), which are easy to implement and have fast responses to near real-time feedback control. But they have limited ability to control the phase of the light field and cannot produce certain types of structured light. They are also prone to speckle, diffraction or other distortions.

enlarge/ Schematic diagram of the experimental setup.

PF Silva & SR Muniz, 2022

The second group includes holography and various phase control methods, which can Generates phase structured light and vector beams. The trade-off is slower control speed and lack of real-time feedback. Silva and Muniz wanted to propose a phase control method to achieve some desirable properties of DMDs and AOMs—in particular, pixel-to-pixel mapping, simple encoding of light patterns, faster feedback, and more precise control.

Essentially, they improved on an earlier method proposed in 2007 , for sharper and smoother results. They polarize diode lasers to match the orientation of liquid crystals for spatial light modulator purposes. They can organize crystals with electromagnetic fields, forming a series of prisms. Programming the modulators allowed Silva and Muniz to use these prisms to create multiple arbitrary geometric shapes—as well as fully detailed images of cats.

enlarge/ Arbitrary geometry generated using this method.

PF Silva & SR Muniz, 2022

” The experimental results we show show that , it is possible to create not only simple and flat geometries using the described method, but also complex and feature-rich images with detailed intensity distributions,” the authors write. Their method may be applicable to shaping beams from higher-power pulsed lasers or even ultrafast lasers.

Useful applications include optical patterning and lithography, and optical trapping of ultracold atoms to create Systems such as Bose-Einstein Condensates (BECs), which are ideal for simulating quantum effects. For example, BECs can “magnify” atoms in the same way a laser magnifies photons, allowing scientists to study the strange little world of quantum physics as if they were looking at it through a magnifying glass. Physicists even managed to tie up “quantum knots” in BECs, and made movies of how the knots decayed or “unwrapped” themselves quickly before forming vortices.

But these are fragile quantum systems and must be handled with care. Therefore, the optical trap has to be very smooth and precise, since any defects would take the atoms out of their quantum state.

“Honestly, I’m not sure you can use ultracold atoms or anything There isn’t any good idea to do things with pictures of cats, but it kind of represents that you can do very fine and precise features,” Muniz told New Scientist. “We can make these beautiful cat images, but we can also use this system to do quantum simulations of electrons and superconductivity [using trapped ultracold atoms].”

DOI: arXiv, 2022. 10.48550/arXiv.2204.09724 (About DOI).

PF Silva & SR Muniz, 2022