Interaction-free imaging of multipixel objects

Quantum imaging, one of the pillars of quantum technologies, is well suited to study sensitive samples which require low-light conditions, like biological tissues. In this context, interaction-free measurements (IFM) allow us to infer the presence of an opaque object without the photon interacting with the sample. Current IFM schemes are designed for single-pixel objects, while real-life samples are structured, multipixel objects. Here we extend the IFM imaging schemes to multipixel, semitransparent objects, by encoding the information about the pixels into an internal degree of freedom, namely orbital angular momentum. This allows us to image the pixels in parallel. Our solution exhibits a better theoretical efficiency than the single-pixel case. Our scheme can be extended to other degrees of freedom, like the photon radial quantum number, in order to image one-dimensional (1D) and 2D objects.