1 Mechanism of s-SNOM The concept of utilizing a near-field technique to circumvent the diffraction limit dates back to the early 20th century,proposed by Edward Synge[1].After the first demonstration of this idea,in ...1 Mechanism of s-SNOM The concept of utilizing a near-field technique to circumvent the diffraction limit dates back to the early 20th century,proposed by Edward Synge[1].After the first demonstration of this idea,in 1972 in microwaves[2]and 1984 in visible light[3,4],various practices with similar near-field approaches emerged.Hillenbrand et al.[5]recently reviewed scattering-type scanning near-field optical microscopy(s-SNOM)as a specific type of near-field scanning technique.The detection limit of this near-field scanning technique is characterized by the sharpness of the metallic tip,rather than the wavelength of the electromagnetic wave.Thus,the potential to scan with a very broad frequency range while maintaining an extremely high spatial resolution(nominally 10-100 nm)makes this proposal extremely promising.By analyzing the local dielectric constantϵ(x)as a function of scanning frequency and controlling other environmental parameters,a wealth of physical information can be extracted.展开更多
文摘1 Mechanism of s-SNOM The concept of utilizing a near-field technique to circumvent the diffraction limit dates back to the early 20th century,proposed by Edward Synge[1].After the first demonstration of this idea,in 1972 in microwaves[2]and 1984 in visible light[3,4],various practices with similar near-field approaches emerged.Hillenbrand et al.[5]recently reviewed scattering-type scanning near-field optical microscopy(s-SNOM)as a specific type of near-field scanning technique.The detection limit of this near-field scanning technique is characterized by the sharpness of the metallic tip,rather than the wavelength of the electromagnetic wave.Thus,the potential to scan with a very broad frequency range while maintaining an extremely high spatial resolution(nominally 10-100 nm)makes this proposal extremely promising.By analyzing the local dielectric constantϵ(x)as a function of scanning frequency and controlling other environmental parameters,a wealth of physical information can be extracted.