We report our recent work on obtaining on-chip lasers in crystalline double tungstate waveguides using focused-ion-beam (FIB) nanostructuring. Photonic cavity structures were defined by forming deeply etched Bragg gratings in KGdxLu1-x(WO4)2:Yb 3+ using FIB milling. The FIB milling procedure was optimized and gratings more than 4 μm in depth with an improved total sidewall angle of about 5 wer...

Lithium niobate LiNbO3, LN is an important material which is widely applied in fabricating photonic and acoustic devices. However, it is difficult to either wet etch or dry etch LN due to the material’s properties. Here, the authors report novel pattern fabrication based on LN using focused ion beam FIB milling. When an array of small holes is etched, a severe tapering problem is observed as is...

High aspect ratio diamond nanocone arrays are formed on freestanding diamond film by means of focused ion beam (FIB) milling technology and hot-filament chemical vapor deposition (HFCVD) method. The structure and phase purity of an individual diamond nanocone are characterized by scanning electron microscopy (SEM) and micro-Raman spectroscopy. The result indicates that the diamond cones with hi...

Magnetic Tunnel Junctions are Spintronic devices constituted by two ferromagnetic layers separated by a nanometric insulating barrier. The theoretical predictions of giant Tunnel Magnetoresistance (TMR) values in fully crystalline Fe(001)/MgO(001)/Fe(001) structures [1] were soon followed by its experimental verification [2,3]. Such giant TMR effect arises from the conservation of the coherence...

This work reviews different types of substrates used for surface-enhanced Raman scattering (SERS) that have been developed in the last 10 years. The different techniques of self-assembly to immobilize metallic nanoparticles on solid support are covered. An overview of SERS platforms developed using nanolithography methods, including electron-beam (e-beam) lithography and focused ion beam (FIB) ...

While metamaterials offer engineered static optical properties, future artificial media with dynamic random-access control over shape and position of meta-molecules will provide arbitrary control of light propagation. The simplest example of such a reconfigurable metamaterial is a nanowire grid metasurface with subwavelength wire spacing. Recently we demonstrated computationally that such a met...

Current approaches to 3D imaging at subcellular resolution using confocal microscopy and electron tomography, while powerful, are limited to relatively thin and transparent specimens. Here we report on the use of a new generation of dual beam electron microscopes capable of site-specific imaging of the interior of cellular and tissue specimens at spatial resolutions about an order of magnitude ...

We report on the fabrication of gallium phosphide (GaP) nanowaveguides of controlled dimensions, as small as 0.03 μm and aspect ratio in excess of 20, using focused ion beam (FIB) milling. A known limitation of this fabrication process for photonic applications is the formation of gallium droplets on the surface. We demonstrate a postfabrication step using a pulsed laser to locally oxidize the ...

The evolution of the grain structure, internal strain, and the lattice misorientations of nanoporous gold during dealloying of bulk (3D) Ag-Au alloy samples was studied by various in situ and ex situ X-ray diffraction techniques including powder and Laue diffraction. The experiments reveal that the dealloying process preserves the original crystallographic structure but leads to a small spread ...

A room temperature scanning Hall probe microscope system utilizing GaAs/AlGaAs and bismuth micro-Hall probes was used for magnetic imaging of ferromagnetic domain structures on the surfaces of crystalline thin film garnets and permanent magnets. The Bi micro-Hall probes had dimensions ranging between 0.25 and 2.8 microm2 and were fabricated using a combination of optical lithography and focused...