Ultrasensitive superresolution microscopy

by Prof. Takayoshi Kobayashi

Advanced Ultrafast Laser Research Center,

The University of Electro-Communications, Japan

By the use of intensity-modulated laser diodes we have implemented pump-probe microscope and have achieved superresolution imaging with shot-noise limited sensitivity with a scheme of balanced detection.

We have demonstrated that sub-diffraction resolution pump-probe imaging with shot-noise limited sensitivity can be carried out using conventional laser diodes with a balanced-detection scheme. The cost of LD was 50 times lower than in the Ti:sapphire laser-based system. Furthermore, LD is maintenance free and power consumption and space occupied by the instruments were reduced in comparison with the mode-locked laser-based system. Blue, red and near-infrared laser diodes are readily available, as they are widely used in optical disks and in optical communication. In recent years, tremendous advances have been made in green-emitting (500–532 nm) InGaN-based LD technology, achieving an output power of more than 100 mW. Furthermore, green to yellow (543–570 nm) LDs with ~3 mW power can be used at room temperature. By incorporating these LDs, our method becomes applicable to various types of probe molecules. Thus, this method offers new opportunities for studying the nanostructures and properties of biological tissues. < back >