High-speed scanning by dual feedback control in SNOM AFM

We have developed a high-speed scanning near-field optical microscope (SNOM )/atomic force microscope (AFM) system including dual feedback controllers. The system includes an additional piezoelectric actuator with fast respons e in the z direction and a correction circuit to eliminate unnecessary comp onents from the feedback signal. From the measurement of a patterned chromi um layer of 2 x 2 mu m(2) checks on a quartz glass plate, we confirmed that our system had more effective feedback control and faster scanning than cu rrent SNOM/AFM systems that use only a piezo-tube. The scanning speed of th e present system was estimated to be about five times faster than that of c urrent SNOM/AFM systems.