The Ma Renmin research team from the School of Physics at Peking University has introduced the innovative narwhal wave function. This breakthrough enables the localization of optical fields far below the diffraction limit in lossless dielectric systems, challenging the long-held belief in nanophotonics that significant localization inevitably leads to high losses. The narwhal wave function uniquely combines local power-law enhancement with global exponential decay, allowing electromagnetic fields to achieve unprecedented focusing and compression across the entire spatial domain.

Leveraging this discovery, the team designed and experimentally verified a three-dimensional singularity dielectric resonator. This resonator boasts a mode volume as small as 5×10⁻⁷λ³, marking the smallest known value in current dielectric systems. Additionally, the research team developed a singularity optical microscope, which has achieved a remarkable spatial resolution of λ/1000. This microscope has successfully performed high-resolution imaging of structures significantly smaller than the wavelength, highlighting its potential applications in super-resolution optical detection and imaging.