Detect the sub-wavelength data by applying a very-small-aperture laser

Abstract

We present a theoretical and experimental research about applying a very-small-aperture laser (VSAL) to detect sub-wavelength data. Near-field distribution of a VSAL, which is essential for the application of such near-field devices, will be affected by the sample or fiber posited in the near-field region of the aperture. When the device is applied to detect the sub-wavelength data, the real resolution depends on the near-field spot size, the divergent angle of the beam and the distance from the aperture to the sample. Experimental results, including the near-field detection of the spot and detection of the sub-wavelength data by using the VSAL, are presented in this paper. We realize the two dimensional scanning about the sub-wavelength data (with the width 600 nm) by employing a VSAL with a 300 nm×300 nm aperture.

Effects of laser light confinement in periodically poled orthorhombic non-centrosymmetric Ba2NaNb5O15 crystals

“…Unfortunately, these techniques show a diffraction limited resolution in the order of the wavelength used [2]. To overcome this limit, near-field scanning optical microscopy (SNOM) has recently emerged as a sub-wavelength resolution optical tool [3][4][5][6][7][8][9][10][11]. The refractive index singularities associated with the presence of ferroelectric domains make ferroelectric domains optically visible by SNOM microscopes as it has been already demonstrated in a variety of transparent ferroelectrics [1,12].…”

Surface plasmon modulated nano-aperture vertical-cavity surface-emitting laser

“…Here we fabricate SP-modulated NA-VCSELs and evaluate the far-field output power radiated from a small aperture. We also describe our present work on fabricating very-small-aperture lasers (VSALs) by applying metal nano-apertures to edge-emitting lasers [10][11][12][13].…”

Oil-immersion or solid-immersion power enhancement of very-small-aperture lasers

“…Here, λ is the wavelength of the light, n ef f is the effective refractive index of the medium, and θ m is the marginal ray angle. In the past twenty years, researchers have presented various technologies for breaking through the limit S, such as coated tapered fibers [1] and very-smallaperture lasers (VSALs) [2][3][4][5][6][7][8][9][10]. Researchers can control the spot size with a sub-wavelength aperture smaller than λ/2.…”