Generation and control of 3D standing wave illumination for wide-field high-resolution 3D microscopic measurement

Abstract

Microscopic imaging is convenient, nondestructive, and has a high-throughput performance and compatibility with a number of applications. However, the spatial resolution of conventional light microscopy is limited to wavelength scale and the depth of field is extremely shallow; hence, it is difficult to obtain detailed 3D spatial data of the object to be measured. In this paper, we propose a new technique for generating and controlling 3D standing wave illumination based on the 3D interference of multiple laser beams. The proposed technique has possibility to provide lateral and axial resolution improvement as well as a wide 3D field of view. The spatial configuration of the interference beams was theoretically examined and the optimal incident angle of the multiple beams was confirmed. Numerical simulations were carried out and confirmed the generation of 3D standing wave illumination and spatial control of the illumination by using the phase shift of incident beams. Furthermore, we develop an experimental apparatus to demonstrate the generation of 3D standing wave illumination by four beam interference and spatial control with a piezoelectric transducer. Finally, basic experiments were performed using nanospheres to verify the generation, spatial intervals, and controllability of the phase shift of 3D standing wave illumination.