Monolithic Setup Research Articles

Software engineering architecture and its promising opportunities

The evolution of software architecture has witnessed the transition from monolithic to microservices, offering enhanced scalability, maintainability, and flexibility. With the rise of Microservices Architecture (MA), containerization has emerged as a pivotal technology to encapsulate microservices in isolated environments, ensuring consistent deployment. This paper delves into the intricate relationship between Microservices Architecture and containerization, focusing on the benefits, challenges, and practical implications of integrating both. Through a comprehensive experimental setup simulating an e-commerce platform, we quantitatively evaluate the performance metrics of a containerized microservices system versus a traditional monolithic setup. Our findings accentuate the performance gains achieved through MA and containerization, while also shedding light on areas that demand caution and further research. The insights presented serve as a beacon for organizations aiming to transition to or optimize their microservices and containerization practices.

Femtosecond laser assisted selective etching of microchannels in lithium niobate.

Here, we report on the fabrication of cm-long microchannels in LiNbO3 by selective etching of femtosecond laser inscribed tracks using hydrofluoric acid. We achieved a 1 cm long microchannel after 300 h of etching a single track inscribed into the volume along the optical axis of LiNbO3. Furthermore, we investigated the dependence of the etching behavior on various writing parameters. Highly selective etching with a selectivity up to 104 was achieved and a functional relationship between the etched depth and time was found. Thus, our results set the first milestone for future fabrication of 3D-hollow microstructures in the volume of LiNbO3 combining its outstanding physical properties such as the strong nonlinearity as well as the acousto- and electrooptic properties with both microfluidic and photonic structures in a monolithic setup.

Remote Raman Sensing Using a Single-Grating Monolithic Spatial Heterodyne Raman Spectrometer: A Potential Tool for Planetary Exploration.

Advances in Raman instrumentation have led to the implementation of a remote dispersive Raman spectrometer on the Perseverance rover on Mars, which is used for remote sensing. For remote applications, dispersive spectrometers suffer from a few setbacks such as relatively larger sizes, low light throughput, limited spectral ranges, relatively low resolutions for small devices, and high sensitivity to misalignment. A spatial heterodyne Raman spectrometer (SHRS), which is a fixed grating interferometer, helps overcome some of these problems. Most SHRS devices that have been described use two fixed diffraction gratings, but a variance of the SHRS called the one-grating SHRS (1g-SHRS) replaces one of the gratings with a mirror, which makes it more compact. In a recent paper we described monolithic two-gratings SHRS, and in this paper, we investigate a single-grating monolithic SHRS (1g-mSHRS), which combines the 1g-SHRS with a monolithic setup previously tested at the University of South Carolina. This setup integrates the beamsplitter, grating, and mirror into a single monolithic device. This reduces the number of adjustable components, allows for easier alignment, and reduces the footprint of the device (35 × 35 × 25 mm with a weight of 80 g). This instrument provides a high spectral resolution (∼9 cm-1) and large spectral range (7327 cm-1) while decreasing the sensitivity to alignment with a field of view of 5.61 mm at 3m. We discuss the characteristics of the 1g-mSHRS by measuring the time-resolved remote Raman spectra of a few inorganic salts, organics, and minerals at 3 m. The 1g-mSHRS makes a good candidate for planetary exploration because of its large spectral range, greater sensitivity, competitively higher spectral resolution, low alignment sensitivity, and high light throughput in a compact easily aligned system with no moving parts.

Preserving Nearly Diffraction-Limited Beam Quality Over Several Hundred Meters of Transmission Through Highly Multimode Fibers

The influence of the core diameter and the fiber length on the beam quality of the transmitted beam was investigated theoretically and experimentally for highly multimode step-index fibers with a numerical aperture of 0.22 using a fully monolithic setup. We show that it is possible to maintain a nearly diffraction-limited beam quality ( M $^{2}\boldsymbol{\approx }$ 1.3) through 100 m long multimode fibers. For a core diameter of $60\,\boldsymbol{\mu}$ m and a fiber length of 380 m one can still deliver a beam with an M $^{2}$ value of 2.1. The high-power suitability of this approach was shown by transmitting 1 kW of power through a 100 m long fiber with a core diameter of $60\,\boldsymbol{\mu}$ m without the onset of stimulated Raman scattering while maintaining a nearly diffraction-limited beam quality ( M $^{2} \boldsymbol{\approx }$ 1.3).

A finite element model for fluid–structure interaction problems involving closed membranes, internal and external fluids

In this paper we propose a Finite Element model for analyzing closed membranes (“bags”) interacting with internal and external (surrounding) fluids. The approach is based on embedding a Lagrangian monolithic model describing the membrane containing an internal fluid into an Eulerian external fluid model. The combination of kinematic frameworks allows us to accurately track the location of the membrane and naturally represent flow variables discontinuities across it. In order to obtain stable coupling for membrane materials with low density, a slight fluid compressibility is assumed. The coupling between the membrane and the internal fluid is automatically accounted for by a monolithic set-up. The filled membrane and the external fluid are coupled in a Dirichlet–Neumann fashion. The model is validated in several numerical examples and its potential application to a civil engineering problem of coast protection via water-filled bag reefs is shown.

Position and time resolution measurements with a microchannel plate image intensifier: A comparison of monolithic and pixelated CeBr3 scintillators

To perform Four Dimensional Age Momentum Correlation measurements in the near future, where one obtains the positron lifetime in coincidence with the three dimensional momentum of the electron annihilating with the positron, we have investigated the time and position resolution of two CeBr3 scintillators (monolithic and an array of pixels) using a Photek IPD340/Q/BI/RS microchannel plate image intensifier. The microchannel plate image intensifier has an active diameter of 40mm and a stack of two microchannel plates in chevron configuration. The monolithic CeBr3 scintillator was cylindrically shaped with a diameter of 40mm and a height of 5mm. The pixelated scintillator array covered the whole active area of the microchannel plate image intensifier and the shape of each pixel was 2.5·2.5·8mm3 with a pixel pitch of 3.3mm. For the monolithic setup the measured mean single time resolution was 330ps (FWHM) at a gamma energy of 511keV. No significant dependence on the position was detected. The position resolution at the center of the monolithic scintillator was about 2.5mm (FWHM) at a gamma energy of 662keV. The single time resolution of the pixelated crystal setup reached 320ps (FWHM) in the region of the center of the active area of the microchannel plate image intensifier. The position resolution was limited by the cross-section of the pixels. The gamma energy for the pixel setup measurements was 511keV.

Single-mode monolithic fiber laser with 200 W output power at a wavelength of 1018 nm.

We report on an ytterbium-doped monolithic fiber laser at a wavelength of 1018 nm with an output power of 200 W in continuous wave operation. The optimal parameters for setting up such a high-power fiber laser with an ytterbium-doped fiber are investigated and discussed in detail. An in-house-developed pump light stripper and a single-mode fused fiber coupler were applied to use the fiber laser for core-pumping of ytterbium-doped high-power fiber amplifiers in a monolithic setup.

Crystalline Waveguide Lasers in the Visible and Near-Infrared Spectral Range

This paper summarizes our recent results on crystalline waveguides and waveguide lasers fabricated by the femtosecond-laser writing technique. Highly efficient waveguide lasers emitting in the near infrared spectral range based on ytterbium and neodymium doped Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> with slope efficiencies above 70% and continuous wave output powers of more than 5 W were demonstrated. Furthermore, pulsed laser operation of passively Q-switched Yb:YAG and Nd:YAG wavequide lasers was achieved by incorporating the saturable absorber Cr <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4+</sup> :YAG in a monolithic setup. Based on fs-laser written curved structures in Yb:YAG, efficient curved waveguide lasers could be demonstrated. Also, waveguide lasers in the visible spectral range were investigated. We achieved laser emission in the green, orange, red and deep-red spectral region and could demonstrate output powers of more than 1 W with waveguides based on praseodymium doped materials. Additionally, switchable and dual wavelength operation between the orange and red laser emission was achieved. By utilizing the nonlinear crystal KTiOPO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> as substrate material for fs-laser inscription, nonlinear waveguides were realized. With these devices, efficient second harmonic generation into the blue and green spectral range was achieved.

Monolithic Tm-Doped Fiber Laser at 1951 nm With Deep-UV Femtosecond-Induced FBG Pair

We report on a monolithic Tm-doped fiber laser emitting in the region <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\sim}{\rm 2}~\mu{\rm m}$</tex> </formula> . A pair of fiber Bragg gratings (FBGs) was written into the Tm-doped fiber using a two-beam interferometry and a deep ultraviolet (DUV) femtosecond laser source at 266 nm. Such a monolithic setup allows a simple setup of the laser made of a single fiber only. This configuration also offers greater reliability because fusion splices inside the resonator cavity could eventually generate failure in the laser cavity. To the best of our knowledge, this is the first rare-earth-doped fiber laser with an FBG pair written by DUV femtosecond laser radiation. Laser characteristics are presented as well as compared with the fiber laser with external FBGs conventionally spliced to the Tm-doped fiber. Dependence of the laser wavelength on the pump power is investigated in detail.

Tunable single frequency thulium:YAG microchip laser with external feedback

By use of the reflection of an uncoated external etalon, a diode-pumped thulium-doped YAG microchip laser was forced into a single-frequency mode. The wavelength of the single-frequency radiation was tunable over 15 nm simply by translation of the etalon relative to the laser. Output powers of 45 mW were achieved in a monolithic setup that is insensitive to vibrations. The origin of the single-frequency oscillation is the wavelength-dependent reflection of the etalon, which is coupled back into the laser resonator. This method permits the combination of inherently stable, single-frequency resonator geometries such as microchips with laser materials that have broad tuning ranges.

Evaluation of liquid properties using a silicon lamb wave sensor

Abstract The design and realization of a Lamb wave oscillator sensor system are described. Both the oscillation frequency and the amplifier gain level are monitored, giving information about the Lamb wave velocity and amplitude, respectively. The system is fabricated in two separate silicon chips (hybrid set-up) or in one chip (monolithic set-up), and can be used for different sensor applications, in liquid or gas environment. We demonstrate the sensor for detection of the density and viscosity of a liquid, and for sensing of the adsorption of human serum albumin (HSA) at the sensor surface.