Using a simple two step fabrication process substrates with large and uniform Raman enhancement, based on flexible free standing nanopillars can be manufactured over areas using readily available silicon processing equipment. Surface enhanced spectroscopy (SERS)1 was discovered in 1974 is now powerful analysis technique which becoming more widespread due to the development of cheaper lasers spectrometer systems. SERS derives information about type chemical bonds trace amounts analyte...

A wafer-scale process for fabricating monolithically suspended nano-perforated membranes (NPMs) with integrated support structures into silicon is developed. Existing fabrication methods are suitable many desired geometries, but face challenges related to mechanical robustness and complexity. We demonstrate a that utilizes the cyclic deposit, remove, etch, multi-step (DREM) directional etching of high-aspect-ratio (HAR) 300 nm in diameter nano-pores 700 pitch. Subsequently, buried cavity...

Fabrication and optical characterization of single-mode polymeric embedded waveguides are performed. A specific material combination (SU-8 2005 as core the modified SU-8 mr-L 6050XP cladding) is chosen in order to obtain a small refractive index difference for propagation combined with conventional fabrication method UV lithography facilitate integration different types detection methods on lab-on-a-chip systems. We analyze behavior carefully observe how value can be tailored during...

The quest to sculpture materials as small and deep possible is an ongoing topic in micro- nanofabrication. For this, the Bosch process has been widely used achieve anisotropic silicon microstructures with high aspect ratio. Reactive ion etching (RIE) lag a phenomenon which etch rate depends on opening areas of patterns, ratio trenches other geometrical factors. not only gives non-uniform distribution scallop size, but it also sets limit for maximum achievable latter since mask suffers from...

The fabrication and performance of an electrophoretic separation chip with integrated optical waveguides for absorption detection is presented. device was fabricated on a silicon substrate by standard microfabrication techniques the use two photolithographic mask steps. were connected to fibers, which enabled alignment free operation due absence free-space optics. A 750 νm long U-shaped cell used facilitate longitudinal detection. To minimize geometrically induced band broadening at turn in...

Robust singlemode operation is reported of an Er3+-doped distributed feedback fibre laser based on a 36 mm long Bragg grating with permanently induced π/2 phaseshift. The integrated into master-oscillator/parametric-amplifier configuration, which yields output power 5.4 mW and has linewidth 15 kHz.

This paper presents the results of an investigation influence soft baking temperature on lithographic performance negative photoresist SU-8. The work was initiated in order to obtain a resolution suitable for integration diffractive optical components near-infrared wavelengths. study carried out 40 µm SU-8 layers thermally oxidized silicon wafers, widespread platform microfluidic systems and waveguides. A series experiments covering bake temperatures range 65–115 °C were performed under...

A transportable miniaturized fiber-pigtailed measurement system is presented which allows quantitative fluorescence detection in microliquid handling systems. The chips are made silica on silicon technology and the optical functionality monolithically integrated with microfluidic channel system. This results inherent stability photolithographic alignment precision. Permanently attached fibers provide a rugged connection to light source, detection, data processing unit, potentially field use...

Sealing of the flow channel is an important aspect during integration microfluidic channels and optical waveguides. The uneven topography many waveguide-fabrication techniques will lead to leakage fluid channels. Planarization methods such as chemical mechanical polishing or etch-back technique are possible, but troublesome. We present a simple efficient alternative: By means changing waveguide layout, bonding pads formed along With same height waveguide, they effectively prevent...

Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of < 15 kHz and sidemode suppression better than 61 dB are presented. The stability the is verified by 10 Gbit/s transmission experiment. Five DFB cascaded pumped single semiconductor laser, thereby forming multiwavelength source for WDM systems.

Molecular beam epitaxy (MBE) of cubic GaN on SiC films deposited by chemical vapor deposition Si has been investigated reflection high-energy electron diffraction, x-ray photoluminescence, and micro-Raman spectroscopy. The wurtzite/zinc-blende ratio, indicative the material quality, found to depend both initial substrate roughness N/metal ratio impinging surface. results were consistently analyzed assuming that MBE growth is mainly governed active N flux, which directly determines mean-free...

The authors present the fabrication and characterization of an integrated optical readout scheme based on single-mode waveguides for cantilever-based sensors. cantilever bending is read out by monitoring changes in intensity light transmitted through that also acts as a waveguide. complete system fabricated photosensitive polymer SU-8. They show theoretical calculations expected sensitivity both when operated air liquid compare these with experimental where deflected mechanically. results...

Abstract Two different black silicon nanostructured surfaces modified with thin gold layers were tested for analytical signal enhancement Surface‐Enhanced Raman Spectroscopy (SERS). The relationship between the thicknesses of and was studied. Also, effects Ti Ti/Pt adhesion underneath on tested. An factor 7.6 × 10 7 excitation laser 785 nm achieved analyte, Rhodamine 6G, non‐resonance SER spectra recorded in a 5 s acquisition mode. Such an enables to achieve detection limit down 2.4 pg 6G...

Three dimensional (3D) silicon micro- and nanostructures enable novel functionalities better device performances in various fields. Fabrication of real 3D structures a larger scale wider applications has been proven to be limited by the technical difficulties during fabrication process, which normally requires multiple process steps techniques. Direct top-down processes modifying plasma etch have proposed studied previous studies. However, repeatability, size uniformity maximal number...

Black silicon (BSi or micro/nanograss) is a frequently encountered phenomenon in highly directional etching of using mainstream plasma etch tools. The appearance BSi most studies considered to be caused by micromasks unintentionally present on the surface that locally prevent from etching. Particularly, under and selective conditions, these chaotically arranged develop into tall grasslike structures will absorb incoming light make etched appear black. There are many different sources might...

The UV wavelength region is of great interest in absorption spectroscopy, which employed for chemical analysis, since many organic compounds absorb only this region. Germanium-doped silica, often preferred as the waveguide core material optical devices telecommunication, cannot accommodate guidance below 400 nm, owing to presence UV-absorbing centers. We show that silicon oxynitride (SiO(x) N(y)) waveguides exhibit very good performance. propagation loss 24-microm -wide SiO(x)N (y) was found...

Strong sampled Bragg gratings are UV induced in planar low-loss silica waveguides. Using such gratings, multichannel wavelength-division-multiplexing (WDM) components can be manufactured with high precision. An ASE filter and add/drop multiplexer have been demonstrated characterized using optical circulators. The exhibits an intraband crosstalk of -30 dB interband -20 when used a 200-GHz channel spacing. Simulations matrix method performed showing that the use uniform is limited by to...

This study focuses on the development of a fluorocarbon-free directional silicon etching process, called CORE (Clear, Oxidize, Remove, and Etch) in which switching sequence SF6 O2 is operated at room temperature. distinguishes it from old-fashioned temperature cryogenic mixed RIE processes as enables higher selectivity, creates pattern independency profiles works excellent The process resembles well-known SF6-based Bosch but usual C4F8 inhibitor replaced by oxidation with self-limiting...

The polarisation properties of a distributed feedback (DFB) fibre laser are investigated experimentally. A birefringent phase-shift is induced by side illumination the centre part lasing structure with ultraviolet (UV) light and it experimentally shown that birefringence dominating effect controlling laser.

Abstract Three‐dimensional photonic crystals (3D PhCs) enable light manipulations in all three spatial dimensions, however, real world applications are still faced with challenges fabrication. Here, a facile fabrication strategy for 3D silicon PhCs simple cubic (SC) lattice structure is presented, which exhibits complete bandgap at near‐infrared wavelengths of around 1100 nm. The process composed standard deep ultra‐violet stepper lithography, followed by single‐run modified plasma etch...

This article describes the realization of complex high-aspect ratio silicon structures with feature dimensions from 100 μm to nm by deep reactive ion etching using Bosch process. As exact shape sidewall profiles can be crucial for proper functioning a device, authors investigated how sacrificial in form guarding walls and pillars may utilized facilitate accurate control etch profile. Unlike other structuring approaches, no silicon-on-insulator substrates or multiple lithography steps are...

Abstract. Relaxed eddy accumulation is still applied in ecosystem sciences for measuring trace gas fluxes. On managed grasslands, the length of time between management events and application relaxed has an essential influence on determination proportionality factor b thus resulting flux. In this study effect discussed first time. Also, scalar similarity proxy scalars interest affected until completely recovered. Against background, CO2 fluxes were continuously measured 13CO2 isofluxes...