Svendsenburnett6104

With the advantages of high information density, high security, high compatibility and ultracompactness, the proposed gray-imaging meta-device can play a significant role in the field of optical storage, anti-counterfeiting, and information multiplexing, etc.Signal enhancement of spectroscopies including terahertz time-domain spectroscopy (THz-TDS) and surface-enhanced Raman scattering (SERS) is a critical issue for effective molecular detection and identification. In this study, the sensing performance between THz-TDS and SERS individually accompanied by the proper plasmonic subwavelength structures was compared. For the precisely quantitative study on the optical properties of rhodamine 6G (R6G) dyes, SERS incorporates with the non-linearly enhanced Raman emissions at the molecular characteristic peaks while THz-TDS refers to the transmittance change and the shift of the spectral resonance. The local molecular density-dependent trade-off relationship between limit-of-detection and quenching was observed from both measurements. The specificity for two samples, R6G and methylene blue, is determined by the discriminations in spectral features such as the intensity ratio of assigned peaks in SERS and transmittance difference in THz-TDS. The comprehension of field enhancement by the specific nanostructures was supported by the finite-element method-based numerical computations. As a result, both spectroscopic techniques with the well-tailored nanostructures show great potential for highly sensitive, reproducible, label-free, and cost-effective diagnosis tools in the biomedical fields.Owing to the characteristics of existing spatial light modulators (SLMs), the computer-generated hologram (CGH) with continuous complex-amplitude is conventionally converted to a quantized amplitude-only or phase-only CGH in practical applications. The quantization of CGH significantly affects the holographic reconstruction quality. In this work, we evaluated the influence of the quantization for both amplitude and phase on the quality of holographic reconstructions by traversing method. Furthermore, we considered several critical CGH parameters, including resolution, zero-padding size, reconstruction distance, wavelength, random phase, pixel pitch, bit depth, phase modulation deviation, and filling factor. Based on evaluations, the optimal quantization for both available and future SLM devices is suggested.In this work, we explore the interrogation of an array of fiber Bragg gratings as part of a laser cavity. A semiconductor optical amplifier in a sigma-shaped fiber cavity provides gain and is gated periodically at a rate that matches the roundtrip time associated with each grating of the array. The interrogator exhibits clear laser properties such as a threshold and linewidth narrowing. Besides improving the signal-to-noise ratio and enabling the re-use of wavelengths, it is found that this interrogation scheme enables monitoring of weak gratings spaced by less than 1 cm. Intracavity grating interrogation studied here is found to be a simple and powerful way to increase the number of sensor points for industrial applications.We demonstrate a comprehensive characterization of the diode-pumped YbBi4Si3O12 laser operating in the continuous-wave and soliton mode-locked regimes. Pumping with a 650 mW, single-transverse mode, fiber-coupled laser diode, a maximum continuous-wave output power amounted to 213 mW with a slope efficiency up to 57.6%. A broadband wavelength tuning range of more than 70 nm was achieved in CW regime with a fused silica prism. Applying a SESAM as mode locker, nearly transform-limited pulses as short as 113 fs were generated for a maximum average power of 53 mW and a pulse repetition rate of ∼106 MHz. To the best of our knowledge, this is the first report on passively mode-locked operation with the YbBi4Si3O12 crystal.Using porous silicon (PSi) interferometer sensors, we show the first experimental implementation of the high contrast cleavage detection (HCCD) mechanism. HCCD makes use of dramatic optical signal amplification caused by cleavage of high-contrast nanoparticle labeled reporters instead of the capture of low-index biological molecules. An approximately 2 nm reflectance peak shift was detected after cleavage of DNA-quantum dot reporters from the PSi surface via exposure to a 12.5 nM DNase enzyme solution. This signal change is 20 times greater than the resolution of the spectrometer used for the interferometric measurements, and the interferometric measurements agree with the response predicted by simulations and fluorescence measurements. These proof of principle experiments show a clear path to achieving a real-time, highly sensitive readout for a broad range of biological diagnostic assays that generate a signal via nucleic acid cleavage triggered by specific molecular binding events.Sub-aperture tool polishing of precision optics requires a detailed understanding of the local material removal [tool influence function (TIF)] at the contact spot between the workpiece and tool to achieve high removal determinism and hence precision of the optic relative to the desired/design surface figure. In this study, the mechanisms influencing and the quantitative prediction of the removal rate and shape of TIF spots during polishing of fused silica glass with cerium oxide slurry using a rotating hemispherical pad-foam tool for a wide variety of process conditions (including tool properties, kinematics, and applied displacements) are investigated. ICI-118551 order The TIF volumetric removal rate can be estimated utilizing the average relative velocity and contact area using a simple analytical model. In addition, stability of the volumetric removal rate for fixed process conditions is shown to be greatly dependent on the pad preparation and amount of tool use (affecting both pad topography and slurry buildup), whose general behavior shows an increase in removal rate followed by stabilization with polishing time. The determination of the TIF removal shape is more complex. An extended version of the Preston removal model is developed to explain a comprehensive set of measured TIF removal shapes to within ∼22%. This model incorporates a number of phenomena impacting the TIF removal shape including (a) temporal and spatial dependent relative velocity between the workpiece and tool; (b) an elastic mechanics based, as well as hydrodynamic, pressure distribution; (c) a spatially dependent friction coefficient possibly caused by both reduced slurry replenishment in low velocity regions and pad slurry islands (100 µm scale) and porosity (millimeter scale); and (d) a shear-based removal mechanism on the periphery of the contact spot.