title: Near-field optical microscopy with video signal processor to apply a CCD imaging device as a variable area photo-sensor for improving operability and spectrum mode imaging.
abstract: We have developed a video signal processor for improving the operability and function of scanning near-field optical microscopy (SNOM). The video signal processor applies a CCD imaging device as a variable area photo-sensor in the SNOM unit instead of conventional photo-detectors. The signal processor converts the intensity of a selected area in video frames to a numerical value with a rate of 30 Hz. Consequently, the CCD imaging device can be used as a photo-detector of variable areas and positions for detecting a small area of a optical probe position. The need for a precise optical axis alignment is relaxed due to the large sensing area of the CCD device. Using the video signal processor, near-field optical and topographic images have been obtained by SNOM/AFM system simultaneously. By adding a spectrometer between the SNOM unit and the CCD device, the spectrum signal of selected wavelength ranges has been monitored by the video signal processor to provide an optical image.
authors.affiliation: Department of R&D, Seiko Instruments, Matsudo, Chiba, Japan. hiroshi.muramatu@sii.co.jp
authors.forename: H
authors.initials: H
authors.lastname: Muramatsu
authors.forename: J M
authors.initials: JM
authors.lastname: Kim