**Inverse-designed metastructures that solve equations....Signal processing of light waves can be used to represent certain mathematical functions and to perform computational tasks on signals or images in an analog fashion. Such processing typically requires complex systems of bulk optical elements such as lenses, filters, and mirrors. Mohammadi Estakhri et al. demonstrate that specially designed nanophotonic structures can take input waveforms encoded as complex mathematical functions, manipulate them, and provide an output that is the integral of the functions. The results, demonstrated for microwaves, provide a route to develop chip-based analog optical computers and computing elements.**

Metastructures hold the potential to bring a new twist to the field of spatial-domain optical analog computing: migrating from free-space and bulky systems into conceptually wavelength-sized elements. We introduce a metamaterial platform capable of... show more

Metastructures hold the potential to bring a new twist to the field of spatial-domain optical analog computing: migrating from free-space and bulky systems into conceptually wavelength-sized elements. We introduce a metamaterial platform capable of

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## Dhan Hurley 1 month ago

(A) A sketch of a closed-loop network, consisting of a suitably designed kernel operator (such as a metamaterial block that performs the desired integral operator on the arbitrary input wave), feedback mechanism to establish recursive wave propagation inside the network, and in/out coupling elements to excite and probe the waves. The N waveguides are used to create the feedback network, in this case an external feedback mechanism. Arrows indicate the direction of the wave flow across the structure. The scattering matrices of the blocks can be found in (36). Green and red curves indicate distribution of g(u) and ∫bag(v)K(u,v)dv, sampled by using N waveguides. (B) Complex density plot representation of the first complex-valued kernel K1(u, v) in the (u, v) plane, as given in Eq. 2. The maximum amplitude of the complex value in the color circle inset is set to 0.5. (C) An arbitrarily chosen complex-valued input signal and (D) simulation results [real (blue) and imaginary (red) parts] extracted from the output... show more

(A) A sketch of a closed-loop network, consisting of a suitably designed kernel operator (such as a metamaterial block that performs the desired integral operator on the arbitrary input wave), feedback mechanism to establish recursive wave propagation inside the network, and in/out coupling elements to excite and probe the waves. The N waveguides are used to create the feedback network, in this case an external feedback mechanism. Arrows indicate the direction of the wave flow across the structure. The scattering matrices of the blocks can be found in (36). Green and red curves indicate distribution of g(u) and ∫bag(v)K(u,v)dv, sampled by using N waveguides. (B) Complex density plot representation of the first complex-valued kernel K1(u, v) in the (u, v) plane, as given in Eq. 2. The maximum amplitude of the complex value in the color circle inset is set to 0.5. (C) An arbitrarily chosen complex-valued input signal and (D) simulation results [real (blue) and imaginary (red) parts] extracted from the output of the coupling elements, by using schematic analysis based on the ideal scattering matrices of all the involved subsystems. Simulation results are compared with the expected theoretical results (dashed lines), showing a good agreement.

## Roy Gardiner 1 month ago

However it seems that it could be the precursor to a completely new computing paradigm:is that correct?

What do you imagine would be the scale and extent of real world applications? I always imagined that optical computers would be the future but I had assumed, because we live in a

digital age, that the computing principle would be, as for most modern electronic computers, fundamentally digital.## Dhan Hurley 1 month ago

Electronic/Optical Analog computers are coming back.This is the future, coupled with Parallel Programming.There is a computer company in Germany (Munich?) selling Electronic Analog and hybrid Analog/Digital computers.

There was a demonstration of an Optical ( Laser ) computer, in Germany, using a natural crystal chip, approximately 30 years ago. This had a base logic of 5 in contrast to "normal" binary computer ( 2 ).

Obviously this was held back by our masters,like a lot of other technology, including TRINARY, which was invented in the 1950's.

..... Dhan

## Roy Gardiner 1 month ago

## Oncle Didine 1 month ago

#metastructures #equations #light #analog #nanophotonic #physics #electronics #optics #science #metamaterial #technology #computer