Different forms of linear transformations, such as the Fourier transform, are widely employed in processing of information in various applications. These transformations are generally implemented in the digital domain using electronic processors, and their computation speed is limited with the capacity of the electronic chip being used, which sets a bottleneck as the data and image size get large. A remedy of this problem might be to replace digital processors with optical counterparts and use light to process information.
Click here for original story, Light computes any desired linear transform without a digital processor
Source: Phys.org