This technology is a novel asymmetrical microstructure capable of generating tunable photonic nanojets (PNJ) allowing super-resolution microscopy. The microstructure has tunable properties allowing generation of multiple PNJs, from ultra-narrow for super-resolution to ultra-long for detection of nanoparticles in biological samples. This technology opens the door for applications beyond super-resolution imaging, such as data retrieval from ultra-high density optical storage as well as nanolithography.