Review of scaling effects on physical properties and practicalities of cantilever sensors

Reducing sensor dimension is a good way to increase system sensitivity and response. However the advantages gained must be weighed against other effects which also became significant during the scaling process. In this paper, the scaling effect of cantilever sensors from micrometre to nanometre regimes is reviewed. Changes in the physical...

Some considerations of effects-induced errors in resonant cantilevers with the laser deflection method

Micro/nano resonant cantilevers with a laser deflection readout have been very popular in sensing applications over the past years. Despite the popularity, however, most of the research has been devoted to increasing the sensitivity, and very little attention has been focused on effects-induced errors. Among these effects, the surface effects...

Compact Mach-Zehnder interferometer based on self-collimation of light in a silicon photonic crystal

We demonstrate a compact silicon photonic crystal Mach-Zehnder interferometer operating in the self-collimation regime. By tailoring the photonic band structure such as to produce self-collimated beams, it is possible to design beam splitters and mirrors and combine these to a 20 × 20 ?m2 format. With transmission spectroscopy we find a...

Photonic crystal Mach-Zehnder interferometer operating in the self-collimation mode of light

Sub-10-nm nanolithography with a scanning helium beam

Scanning helium ion beam lithography is presented as a promising pattern definition technique for dense sub-10-nm structures. The powerful performance in terms of high resolution, high sensitivity, and a low proximity effect is demonstrated in a hydrogen silsesquioxane resist.

Wavelength-sized, tunable nanocavity in deeply etched InP/InGaAsP/InP photonic crystals

Wavelength-sized point defect cavities coupled to access waveguides are reported for deeply etched InP/InGaAsP/InP two-dimensional photonic crystals. The observed quality factor of 60 is comparable to those found for one-row defect Fabry–Perot cavities and for simple point defect cavities in membranes. The quality factor was changed by varying...

Size-dependent effective Young’s modulus of silicon nitride cantilevers

The effective Young’s modulus of silicon nitride cantilevers is determined for thicknesses in the range of 20–684 nm by measuring resonance frequencies from thermal noise spectra. A significant deviation from the bulk value is observed for cantilevers thinner than 150 nm. To explain the observations we have compared the thickness dependence of...

Effect of undercut on the resonant behaviour of silicon nitride cantilevers

We present a systematic investigation of the dynamic properties of silicon nitride cantilevers in air. The thermal noise spectra of cantilevers have been measured using a home-made optical deflection setup. Torsional and flexural resonances up to the seventh mode are observed. The dependence of resonance frequencies on the dimensions and mode...

Influence of hydrogen silsesquioxane resist exposure temperature on ultrahigh resolution electron beam lithography

Performance of hydrogen silsesquioxane (HSQ) resist material with respect to the temperature during electron beam exposure was investigated. Electron beam exposure at elevated temperatures up to 90?°C shows sensitivity rise and slight contrast (?) degradation compared to lower temperature cases. Ultrahigh resolution structures formed at elevated...

Comparative study of Cl2, Cl2/O2, and Cl2/N2 inductively coupled plasma processes for etching of high-aspect-ratio photonic-crystal holes in InP

An extensive investigation has been performed on inductively coupled plasma etching of InP. An important motivation for this work is the fabrication of high-aspect-ratio holes for photonic crystals. The essential chemistry is based on Cl2 with the addition of N2 or O2 for sidewall passivation. The influence of different process parameters such...

Transmission measurement of the photonic band gap of GaN photonic crystal slabs

A high-contrast-ratio (30 dB) photonic band gap in the near-infrared transmission of hole-type GaN two-dimensional photonic crystals (PhCs) is reported. These crystals are deeply etched in a 650 nm thick GaN layer grown on sapphire. A comparison of the measured spectrum with finite difference time domain simulations gives quantitative agreement...

Asymmetry reversal and waveguide modes in photonic crystal slabs

The measured reflection spectra of two-dimensional photonic crystal slabs consist of an asymmetric peak on top of an oscillating background. For p-polarized light, the asymmetry of the peak flips for angles of incidence beyond Brewster’s angle. We explain the observed line shapes with a Fano model that includes loss and use a waveguide model to...

High-dose exposure of silicon in electron beam lithography

Polarization tomography of metallic nanohole arrays

We report polarization tomography experiments on metallic nanohole arrays with square and hexagonal symmetry. As a main result we find that a fully polarized input beam is partly depolarized after transmission through a nanohole array. This loss of polarization coherence is found to be anisotropic; i.e., it depends on the polarization state of...

The role of electron electron double resonance in span relaxation studies on radicals in liquid solutions