Subwavelength imaging using a solid-immersion diffractive optical processor

Researchers have developed a solid-immersion diffractive optical processor for subwavelength imaging of phase and amplitude objects. This innovative system uses diffractive encoding and decoding to transmit high-frequency information through a solid-immersion layer and air, respectively. By jointly optimizing the encoder and decoder layers using deep learning, the system can magnify images and reveal subwavelength features that would otherwise be lost due to diffraction limits. The compact design of this all-optical collaboration allows for resolving subwavelength features in a cost-effective manner. Experimental demonstrations using terahertz radiation show successful phase-to-intensity transformations and reconstruction of subwavelength phase features. The system's design enables it to generalize to unseen objects and operate at different parts of the electromagnetic spectrum without redesigning the components. This solid-immersion diffractive imager has the potential for applications in bioimaging, endoscopy, sensing, and materials characterization due to its high spatial resolution capabilities.