Simultaneous scanning tunneling microscope and collection mode scanning near-field optical microscope using gold coated optical fiber probes

Simultaneous scanning tunneling microscope (STM) and collection mode scanning near-field optical microscope (SNOM) images using tunneling regulation are presented. The images were obtained using a gold coated single optical fiber as both a tunneling and near-field optical probe. The method counts on the reliable STM distance regulation and the short separation between tip and sample (<1 nm). Using optimized fiber probes, both STM and SNOM images show good resolution and image contrast. We describe the STM/SNOM system and present the first images obtained in the collection mode with calibration samples of gratings of period down to 200 nm.