A CAVITY-SNOM (SCANNING NEAR-FIELD OPTICAL MICROSCOPY) HEAD USING A LASER-DIODE

A cavity-SNOM (scanning near-field optical microscope) head using a la ser diode is proposed and studied theoretically and experimentally, Th eoretically, we study the optical properties using conventional rate e quations. Several conditions to detect the SNOM signal with a photodio de are discussed. Experimentally, the dependence of output power of th e laser diode on the injection current is measured. A sufficiently str ong modulation signal is detected using a tapered fiber as the probe, but no modulation signal is detected using a tapered fiber with a smal l aperture (SNOM probe). The conditions for detecting a signal using a SNOM probe are also discussed, and we suggest that a laser diode with a SNOM probe fabricated on its facet is essential for realizing a pra ctical cavity-SNOM head.