Mcbridedejesus1831

Image-guided and robotic surgery based on endoscopic imaging technologies can enhance cancer treatment by ideally removing all cancerous tissue and avoiding iatrogenic damage to healthy tissue. Surgeons evaluate the tumor margins at the cost of impeding surgical workflow or working with dimmed surgical illumination, since current endoscopic imaging systems cannot simultaneous and real-time color and near-infrared (NIR) fluorescence imaging under normal surgical illumination. To overcome this problem, a bio-inspired multimodal 3D endoscope combining the excellent characteristics of human eyes and compound eyes of mantis shrimp is proposed. This 3D endoscope, which achieves simultaneous and real-time imaging of three-dimensional stereoscopic, color, and NIR fluorescence, consists of three parts a broad-band binocular optical system like as human eye, an optical relay system, and a multiband sensor inspired by the mantis shrimp's compound eye. By introducing an optical relay system, the two sub-images after the broad-band binocular optical system can be projected onto one and the same multiband sensor. A series of experiments demonstrate that this bio-inspired multimodal 3D endoscope not only provides surgeons with real-time feedback on the location of tumor tissue and lymph nodes but also creates an immersive experience for surgeons without impeding surgical workflow. Its excellent characteristics and good scalability can promote the further development and application of image-guided and robotic surgery.For a squeezing-enhanced linear (so-called SU(2)) interferometer, we theoretically investigate the possibility to broaden the phase range of sub-shot-noise sensitivity. We show that this goal can be achieved by implementing detection in both output ports, with the optimal combination of the detectors outputs. With this modification, the interferometer has the phase sensitivity independent of the interferometer operation point and, similar to the standard dark port regime, is not affected by the laser technical (excess) noise. Provided that each detector is preceded by a phase-sensitive amplifier, this sensitivity could be also tolerant to the detection loss.This work presents an analytical coupling model for perturbed abrupt fiber tapers in single-mode fibers. In addition to LP0m modes, the modeling predicts the presence of LP11 and LP12 modes for a bent taper. Our model also introduces a perturbation function that can match most cases of bending variations on a taper. We have shown that the tapering and bending effect can be treated separately within one abstract formulation. Agreement amongst the model predictions and experimental results support the viability of our method.In this work, we present an efficient polarization conversion device via using a hollow graphene metasurface. The platform can simultaneously realize a series of excellent performances, including the broadband x-to-y cross polarization conversion (CPC) function with near unity polarization conversion ratio (PCR), dual-frequency linear-to-circular polarization conversion (LTC-PC) function, and highly sensitive polarization conversion function manipulation under wide oblique incidence angle range. For instance, the proposed device obtains an x-to-y CPC function with the bandwidth up to 1.83 THz (χPCR ≥98.8%). Moreover, the x-to-y CPC function can be switched to LTC-PC function via artificially tuning the Fermi energy of graphene. The maximal frequency shift sensitivity (S) of polarization conversion function reaches 23.09 THz/eV, suggesting a frequency shift of 2.309 THz for the LTC-PC function when the chemical potential is changed by 0.1 eV. Based on these superior performances, the polarization converter can hold potential applications in integrated and compact devices, such as polarization sensor, switches and other optical polarization control components.Complex lightwave manipulation such as broadband absorption has been realized with metasurfaces based on laterally arranged metal-dielectric-metal cavities with different geometries. However, application of these metasurfaces for optoelectronic devices by incorporating functional dielectrics remains challenging. Here, we integrate a quantum well infrared photodetector (QWIP) with a metasurface made of a patchwork of square cavities with different dimensions arranged in a subwavelength unit cell. Our detector realizes wideband photoresponse approaching the entire responsivity spectrum of the QWIP-single-sized square cavities can utilize only 60% of the possible bandwidth-and external quantum efficiencies of up to 78% at 6.8 µm. Our highly flexible design scheme enables integration of photodetectors and metasurfaces with arbitrary arrangements of cavities selectively responding to incidence with a specific wavefront.A novel fiber optic localized surface plasmon resonance (LSPR) hydrogen sensor has been developed based on the hetero-core structured with palladium nanoparticles (PdNPs) onto a cylindrical cladding surface. In a light-intensity-based experiment with an LED operating at 850 nm, it has been observed that a transmitted loss change of 0.23 dB was induced with response and recovery times of 1.5 and 3.2 s for 4% hydrogen which are the fastest response times among optical fiber hydrogen sensors. The proposed sensor resolved the inevitable trade-off issue between sensitivity and response time which existed in the previously reported SPR sensors, with keeping the response time below 2.0 s even in a high sensitivity region of interest.Silicon-based Yb-doped Y3Al5O12 garnet nanofilms are fabricated by atomic layer deposition, which are polycrystalline after annealing at 1150 °C. The sub-nanometer compositional regulation and the Yb2O3 cladding layers, which also work as the luminescent dopants, are critical for the crystallization. Characteristic Yb3+ luminescence at 1030 nm and 970 nm is identified under electrical injection, exhibiting the external quantum efficiency of 0.65% and the fluorescence lifetime of 80-200 µs. The doped Yb3+ are impact-excited by hot electrons stemming from Fowler-Nordheim tunneling mechanism within the Y3Al5O12 matrix, with the excitation cross section of 0.7×10-15 to 6.4×10-15 cm2. This work certifies the manipulation of multi-oxide nanofilms with designed composition and crystallinity, revealing the possibility of developing Si-based optoelectronic devices from crystalline garnet films.The study of the optical transmission matrix (TM) of a sample reveals important statistics of light transport through it. The accuracy of the statistics depends strongly on the orthogonality and completeness of the basis in which the TM is measured. While conventional experimental methods suffer from sampling effects and optical aberrations, we use a basis of Bessel modes of the first kind to faithfully recover the singular values, eigenvalues and eigenmodes of light propagation through a finite thickness of air.Metasurface based polarization multiplexing is usually conducted in two orthogonal-polarization states, e.g., linearly polarized along x/y axes, left/right-handed circularly polarized states, etc. Herein, we show metasurfaces can be employed to implement tri-channel polarization multiplexing in three non-orthogonal-polarization states, merely with a single-size nanostructure design approach. Specifically, nanostructured metasurfaces acting as nano-polarizer arrays can modulate the incident light intensity pixel-by-pixel by controlling the orientation angles of nanostructures, governed by Malus's law. Hence, by inserting a metasurface between a bulk-optic polarizer and an analyzer, and elaborately controlling their polarization combinations, we show that the Malus-assisted metasurface can simultaneously record a continuous gray-image and two independent binary-patterns in three different information channels. We experimentally demonstrate this concept by recording three independent gray-images right at the metasurface surface. 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. read more 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.