Laser micro/nano fabrication in glass with tunable-focus particle lens array

Abstract

Based on medium-tuned optical field enhancement effect around a self-assembled particle-lens array (PLA) irradiated with a femtosecond (fs) laser source, we demonstrated that high-precision periodical array of micro/nano-structures can be readily fabricated on glass surface or inside glass in large areas in parallel without any cracks or debris. The technique has potential for rapid fabrication of three-dimensional structures in multiple layers inside glass.

3-D patterning of silicon by laser-initiated, liquid-assisted colloidal (LILAC) lithography

“…2(b)). The extension of focal length predicted by use of a colloidal particle immersed in a liquid with n liquid slightly smaller than n colloid could offer a route to enhanced energy coupling deeper within the substrate [5]. Conversely, when n liquid > n colloid (case (ii)), the largest field enhancements are predicted at the 'edges' of the colloidal particle (Fig.…”

“…Surface nanopatterning can be achieved in a number of ways -e.g. ion and e-beam lithography [1], dip pen lithography using the tip of an atomic force microscope [2], localized excimer-laser irradiation [3] or by using the nearfield effects induced by laser irradiating microsphere-covered substrates in air [4] or in a liquid medium [5]. A layer of microspheres directly on the surface acts as an array of near-field lenses that focusses the incident radiation into a multitude of spots, thereby inducing formation of an organized array of nanostructures in a single step.…”

Laser micro machining beyond the diffraction limit using a photonic nanojet

“…The intensity distribution of a PNJ can be controlled by the wavelength [4,5] and polarisation [6] of the incident laser light, the diameter [4,7] and refractive index [4,8] of the microsphere, and the refractive index of the medium surrounding the microsphere [9][10][11][12]. The important parameters of PNJ for laser micromachining are the beam diameter, which is defined by the full width at half maximum (FWHM), the distance from the microsphere surface to the position of peak intensity (i.e.…”

Femtosecond Optical Trap-Assisted Nanopatterning through Microspheres by a Single Ti:Sapphire Oscillator

“…Near-field intensity distribution is strongly affected by the refractive index of the surrounding media. 8 We assume the media to be uniform, with the refractive index equal to 1.33 (refractive index of water). Figure 2 demonstrates a typical crater formed without beads and a crater produced using the bead as a lens to focus the processing femtosecond laser beam when the bead is optically trapped by the same femtosecond laser beam.…”