Fig. 6

Class-specific linear transformation camera. a Illustration of a seven-layer diffractive camera trained to perform a class-specific linear transformation (denoted as \({\varvec{T}}\)) with instantaneous all-optical erasure of the other classes of objects at its output FOV. This class-specific all-optical linear transformation operation performed by the diffractive camera results in uninterpretable patterns of the target objects at the output FOV, which cannot be decoded without the knowledge of the transformation matrix, \({\varvec{T}}\), or its inverse. By applying the inverse linear transformation (\({{\varvec{T}}}^{-1}\)) on the output images of the diffractive camera, the original images of interest from the target data class can be faithfully reconstructed. On the other hand, the input objects from the other data classes end up in noise-like patterns both before and after applying the inverse linear transformation, demonstrating the success of this class-specific linear transformation camera design. The output images were normalized using the same constant for visualization. b Phase modulation patterns of the converged diffractive layers of the class-specific linear transformation camera