Another approach to all-optical parallel computing Leave a comment

Optical computing is tempting however unwieldy expertise.

In precept it may be inherently parallel – a wavefront is successfully a 2D matrix of depth (or section, or polarisation) values, and if that is processed by means of an optical system, each level on that matrix is processed on the similar time – a second order stage of parallisation.

And a few optical parts naturally carry out mathematical features with just about no vitality requirement – easy lenses can carry out Fourier transforms, for instance.

Nonetheless, what is well doable can differ extensively from what computation is required, these programs don’t essentially lend them selves to miniaturisation, and reprogramming is a matter.

The Tokyo approach is a multi-function optical approach dubbed ‘diffraction casting’, the place an enter picture passes although a stack of processing layers, diffractive in nature, collectively forming a diffractive neural community which performs logical operations on the picture.

“Within the Nineteen Eighties, researchers in Japan explored an optical computing technique known as shadow casting, which may carry out some easy logical operations,” stated Tokyo Data Photonics Lab scientist Ryoichi Horisaki. “However their implementation was based mostly on comparatively cumbersome geometric optical varieties. They labored in precept, however lacked flexibility and ease of integration to make one thing helpful.”

“Shadow casting relies on gentle rays interacting with completely different geometries,” Horisaki went on the clarify, “whereas diffraction casting relies on properties of the sunshine wave itself, which leads to extra spatially environment friendly, functionally versatile optical parts which can be extensible in methods you’d anticipate and require for a common pc.”

The approach has been simulated, utilizing 16 x 16 pixel monochrome enter pictures, “performing the 16 primary logic operations on the coronary heart of a lot info processing”, stated fellow researcher Ryosuke Mashiko.

It “yielded very optimistic outcomes”, stated Horisaki.

Diffraction casting isn’t sufficient for a whole optical pc.

“It is perhaps finest to consider it as a further element slightly than a full substitute of current programs,” stated Mashiko. “There’s additionally scope for extending our system into quantum computing. A lot work needs to be executed on the bodily implementation, which, though grounded in actual work, has but to be constructed.”

Above is just the briefest skim by means of the expertise. For these wanting extra, the paper ‘Diffraction casting’ is available in full without payment from the SPIE digital library‘