Generation of Dark Hole using an Annular Spiral Phase Plate and an Annular Wave Plate

In this study, we designed, fabricated and evaluated a dark hole generation optical system that combines an annular phase plate and an annular wave plate for super-resolution microscopy based on stimulated emission or upconversion fluorescence depletion. The phase plate is a compound phase plate that combines two types of spiral phase plates in a ring shape, and the wave plate is a ring shape combination of two types of wave plates with crystal axes perpendicular to each other. Despite its complex structure, the composite phase plate could be precisely fabricated using the exposure and etching processes used in semiconductor manufacturing. A super-resolution microscope equipped with these devices confirmed the generation of a three-dimensional dark hole of fluorescence-suppressed light. © 2024 The Institute of Electrical Engineers of Japan.