Multi-stage Amplification Research Articles

Optimized design of a compact multi-stage displacement amplification mechanism with enhanced efficiency

Mechanically amplifying micro-stroke of actuators such as piezoelectric stacks through compliant mechanisms is an effective solution for use in micro/nano manipulation, precision positioning, gripping and manufacturing with large enough workspaces. This paper proposes a novel type of hybrid three-stage compliant displacement amplifier with a compact structure by synthesizing bridge-type and lever-type compliant mechanisms. A new index is introduced to measure its displacement amplification efficiency by considering the whole size and input stiffness. To facilitate design, the dynamic stiffness model is also derived to capture its kinetostatics and dynamics on both time and frequency domain. Then, the key structural parameters are efficiently optimized with the Pareto multi-objective optimization strategy. The capacity curve in terms of the resonance frequency, displacement amplification ratio and load capacity (output stiffness) is provided as well in a form of the Pareto optimal solution set. Experimental tests of two prototypes indicate a high displacement amplification efficiency of the current design, of which one prototype exhibits the output displacement of 0.7 mm and the resonance frequency of 874 Hz with a compact size of only 57 mm × 50 mm × 10 mm.

A smartphone-assisted microarray immunosensor coupled with GO-based multi-stage signal amplification strategy for high-sensitivity detection of okadaic acid

Okadaic acid (OA) is one of the main virulence factors of diarrheal shellfish toxins (DSP), which can cause acute carcinogenic or teratogenic effects after ingestion of contaminated shellfish. Therefore, high-sensitivity and fast detection of OA is a key to preventing the occurrence of safety accidents. In this paper, we effectively established a smartphone-assisted microarray immunosensor combined with an indirect competitive ELISA (iELISA) for quantitative colorimetric detection of OA. To further improve the detection sensitivity and match the smartphone imaging, a novel graphene oxide (GO) composite probe was developed to realize the multi-stage signal amplification. The system exhibited a wide linear range for the detection of OA (0.02–33.6 ng ·mL−1) with low detection limit of 0.02 ng ·mL−1. The recovery of OA in spiked shellfish samples was in the range of 80%–103.5%, which indicates the good applicability of this biosensor. The whole detection system has advantages of simplicity, low cost, high sensitivity and portability, which is expected to be a powerful alternative tool for on-site detecting and early warning of the pollution of marine products.

Design and Analysis of a 2-D Piezoelectric Platform Based on Three-Stage Amplification and L-Shaped Guiding

In piezoelectric micro-positioning platforms, the displacement amplification mechanism can solve the small output displacement of the platform; the displacement coupling will also increase when the displacement is amplified. To solve the problem of multistage displacement amplification and displacement coupling after multistage displacement amplification, this study proposes a two-dimensional piezoelectric platform based on three-stage amplification and L-shaped guiding. First, the structure of the two-dimensional piezoelectric platform is designed and its working principle is described. Next, the two-dimensional piezoelectric platform is analyzed theoretically, and the static and dynamic characteristics of the structure are analyzed by the finite element method. Finally, a prototype of the two-dimensional piezoelectric platform is fabricated, and the theoretical and simulation results are analyzed experimentally. The experimental results reveal that the platform has a motion range of 31.8 μm × 41 μm. The multistage displacement amplification ratio is 21.8, and the displacement coupling error is less than 4.2%. The positioning error of the closed-loop control platform is less than 0.5%, and the trajectory tracking error is less than 1.6%. Compared with the traditional piezoelectric micro-positioning platform, the three-stage amplification and L-shaped guiding mechanism can effectively improve the displacement magnification and decoupling performance of the piezoelectric micro-positioning platform as well as the positioning ability and trajectory tracking ability of the platform under closed-loop control, which is expected to be utilized in fields such as multi-stage amplification micro-positioning platforms and dynamic optical systems.

Development of Ultrasonic Elliptical Vibration Cutting Device with Multi-stage Amplification Function

Development of Ultrasonic Elliptical Vibration Cutting Device with Multi-stage Amplification Function

Review of the Yb3+:ScBO3 Laser Crystal Growth, Characterization, and Laser Applications

Passive Q-switching is an effective approach for generating pulsed lasers, owing to its compact and additional modulation-free design. However, to compare favorably with active Q-switching and multi-stage amplification, the output energy needs to be enhanced for practical applications. Kramers Ytterbium ion (Yb3+)-doped borate crystals, with their excellent energy storage capacity, have been proven to be high-potential laser gain mediums for achieving pulsed lasers with moderate and high output energy using passive Q-switching technology. In this study, the growth, characterization, and laser generation of one Yb3+-doped borate crystal, the Yb3+:ScBO3 crystal, are systematically reviewed. The continuous-wave and passive Q-switching laser characteristics are presented in detail, and the self-pulsations derived from intrinsic ground-state reabsorption are also demonstrated. The specific characteristics and experiments confirm the potential of the Yb3+:ScBO3 crystal for future pulsed laser applications with moderate or even high energy output.

High-stability, high-beam-quality, and pulse-width-tunable 1319 nm laser system for VISAR applications in high-power laser facilities.

A high-energy, high-beam-quality, and pulse-width-tunable Nd:YAG laser system, pumped by vertical cavity surface emitting laser arrays and laser diodes, is demonstrated and applied to a velocity interferometry system for any reflector (VISAR) application in a high power laser facility. A multistage multipass amplification structure is used to fully extract the amplifier energy and obtain a high-energy pulse. The temporal waveform is compensated to provide a square waveform, with a flatness less than 8% (peak-to-peak value). The peak power is greater than 100 kW with a frequency-doubling efficiency of 25% for a 50 ns pulse width. The laser operates as a single shot with 1-5 Hz repetition frequency and 0.7% rms energy stability.

Comparative Simulation Study of Multi Stage Hybrid All Optical Fiber Amplifiers in Optical Communications

Abstract This study clarifies the comparison between hybrid all optical fiber amplifiers in single-stage and multi-stage amplification. EDFA/Raman, Raman/EDFA/Raman, and EDFA/Raman/EDFA configurations are employed for upgrading optical communication systems. Single-stage Raman amplifiers clarifies very better performance than single-stage EDFA amplifier. Multi-stage Raman/EDFA/Raman also outlines very better performance than other hybrid configuration up to 475 km distance. Single-stage Raman amplification has outlined maxi. Q factor up to 218.392 for 250 km distance and 11.937 up to 475 km propagation range. So hybrid all optical amplifiers are essentially for upgrading optical system performance efficiency.

Mass spectrometric quantification of microRNAs in biological samples based on multistage signal amplification

This work describes a novel method for quantification of miRNAs based on multistage signal amplification (MSA) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The multistage signal amplification involves hybridization enrichment of miRNA targets with a DNA probe-magnetic bead conjugate, target recycling amplification with a duplex-specific nuclease, and acid hydrolysis of the reporter molecules producing free nucleobases. Nucleobases thus generated are quantified by LC-ESI-MS/MS with specificity and repeatability. Taking miR-21 as the model target, biological samples such as serum and cell cultures were analyzed by using the present protocol. The analytical results indicate that facile and cost-effective quantifications of miRNA targets can be achieved by using the popular LC-ESI-MS/MS technique, and very importantly, without an isolation of total RNAs from the sample prior to the quantitative assay. The assay for miR-21 detection had a linear calibration curve in the range from 0.2 pM to 0.25 nM with a limit of detection of 60 fM. Analysis of MCF-7 cells treated with toremifene (a potent inhibitor of breast cancer cell growth) revealed that the content of miRNA-21 decreased by ca. 50%, and the decrease was dose-dependent.

Achievable Rates and Signal Detection for Photon-Level Photomultiplier Receiver Based on Statistical Non-Linear Model

We characterize the practical receiver in a wide range of signal intensity for optical wireless communication, from discrete pulse regime to continuous waveform regime. We first propose a statistical non-linear model based on the photomultiplier tube (PMT) multi-stage amplification and Poisson channel, and then derive the optimal and tractable suboptimal duty cycle with peak-power and average-power constraints for on-off key (OOK) modulation in linear regime. Subsequently, a threshold-based classifier is proposed to distinguish the PMT working regimes based on the non-linear model. Moreover, we derive the approximate performance of mean power detection with infinite sampling rate and finite over-sampling rate in the linear regime based on small dead time and central-limit theorem. We also fomulate a signal model in the non-linar regime. Furthermore, the performance of mean power detection and photon counting detection with maximum likelihood (ML) detection for different sampling rates is evaluated from both theoretical and numerical perspectives. We can conclude that the sample interval equivalent to dead time is a good choice, and lower sampling rate would significantly degrade the performance.

Design of a Novel Two-Directional Piezoelectric Energy Harvester With Permanent Magnets and Multistage Force Amplifier.

This article presents the design and testing of a novel two-directional (2-D) piezoelectric stack-based energy harvester for capturing the mechanical energy from the human footstep. The uniqueness of the harvester lies in the fact that the energy of 2-D excitation is scavenged by a single piezoelectric stack transducer, which can reduce the loss of harvestable energy. The harvester is constructed by the integration of permanent magnets, position protection plates, and multistage force amplification frame. The input force and input displacement are restricted to guarantee the device's safety. The reported multistage force amplification frame with leverage mechanism and bridge-type amplifier enlarges the force acting on the piezoelectric stack, which further improves the power output. A linear guiding mechanism based on leaf flexure is applied to minimize the impact of input forces in other than moving directions. Through analytical modeling, the main architectural parameters of the device are determined. Simulation study with finite-element analysis is conducted to optimize the device parameters for achieving the largest force amplification ratio with a high safety factor. A prototype harvester is fabricated for experimental study. Results demonstrate the feasibility of the developed 2-D piezoelectric stack-based energy harvester.

Design and analysis of a large-range precision micromanipulator

This paper proposes the design of a novel flexure-based micromanipulator dedicated to micro/nano manipulation and assembly tasks. The micromanipulator can provide a millimeter-scale operation range with high accuracy by the piezoelectric actuation. It is mainly enabled by a novel mechanical structure with a multi-stage amplification mechanism and a dual-stage grasping end-effector. Strain-type position and force sensors are integrated to detect the output motion and grasping force of the micromanipulator, respectively. Analytical models are established to predict the kinematic, static and dynamic characteristics, with further verification through finite element analysis. Finally, the principle prototype is fabricated, with which strain-gauge calibration and performance tests are conducted. Experimental results demonstrate that the micromanipulator has an operation range of 1 mm, high displacement/force resolution, and large grasping force. All of the results indicate the excellent characteristics of the developed micromanipulator that is expected to be applied into practical industrial applications.

Conceptual Design of a Laser Driver for a Plasma Accelerator User Facility

The purpose of the European project EuPRAXIA is to realize a novel plasma accelerator user facility. The laser driven approach sets requirements for a very high performance level for the laser system: pulse peak power in the petawatt range, pulse repetition rate of several tens of Hz, very high beam quality and overall stability of the system parameters, along with 24/7 operation availability for experiments. Only a few years ago these performances were considered unrealistic, but recent advances in laser technologies, in particular in the chirped pulse amplification (CPA) of ultrashort pulses and in high energy, high repetition rate pump lasers have changed this scenario. This paper discusses the conceptual design and the overall architecture of a laser system operating as the driver of a plasma acceleration facility for different applications. The laser consists of a multi-stage amplification chain based CPA Ti:Sapphire, using frequency doubled, diode laser pumped Nd or Yb solid state lasers as pump sources. Specific aspects related to the cooling strategy of the main amplifiers, the operation of pulse compressors at high average power, and the beam pointing diagnostics are addressed in detail.

An alternative view of coherent synchrotron radiation induced microbunching development in multibend recirculation arcs

Abstract Coherent synchrotron radiation (CSR) induced microbunching instability has been one of the most challenging issues in the design of modern accelerators. We recently developed a semi-analytical Vlasov solver and applied it to the investigation of the physical processes associated with microbunching amplification for several types of recirculation arc lattices. In this study, we build on the concept of stage gain, proposed by Huang and Kim (2002), and develop an alternative view to characterize CSR microbunching development in terms of stage orders. The stage orders enable a fair and quantitative comparison of the impact of lattice optics on the microbunching development for different lattices under similar initial beam parameters. The multibend arcs considered in this study have a distinguishing feature of multistage amplification. The CSR microbunching gain grows as a six-stage amplification for the presented recirculation arcs with a total of 24 dipoles, while two-stage amplification was previously concluded for a three-dipole bunch compressor chicane. We also attempt to relate the lattice optics pattern with the obtained stage gain functions through a physical interpretation. The investigation in this paper may serve as a complementary discussion to our previous work (Tsai et al., 2017).

The Design of the Biomagnetic Field Sensor without Magnetic Shielding

Due to the extremely weak intensity of the biomagnetic field and the serious interference from the environmental magnetic field, the detection of the biomagnetic field becomes such challenging work. After analyzing the deficiencies in the current biomagnetic field sensors, this paper proposes and realizes a high-sensitivity magnetic field sensor, based on the giant magneto-impedance (GMI) effect. Taking advantage of the miniaturized magnetic probe, the multistage multiple amplification and the multiband interference suppression, our sensor mainly makes three achievements: the pT level magnetic resolution, the ability to detect the muscle magnetic field without the magnetic shielding and the resistibility to a small-range wobbling in the state of working, which makes it possible to detect the biomagnetic field by wearable sensors under natural conditions.

High-Power Femtosecond Soft X Rays from Fresh-Slice Multistage Free-Electron Lasers.

We demonstrate a novel multistage amplification scheme for self-amplified spontaneous-emission free electron lasers for the production of few femtosecond pulses with very high power in the soft x-ray regime. The scheme uses the fresh-slice technique to produce an x-ray pulse on the bunch tail, subsequently amplified in downstream undulator sections by fresh electrons. With three-stages amplification, x-ray pulses with an energy of hundreds of microjoules are produced in few femtoseconds. For single-spike spectra x-ray pulses the pulse power is increased more than an order of magnitude compared to other techniques in the same wavelength range.

High power LP11 mode supercontinuum generation from an all-fiber MOPA.

High power LP11 mode supercontinuum is generated from 25/250 large mode area (LMA) fiber. A mechanical long period grating (LPG) is utilized to control the transverse modes in the LMA fiber to realize the LP11 mode supercontinuum generation in a master oscillator power amplifier (MOPA) configuration. The generated LP11 mode supercontinuum covers the spectral range from ~900 nm to ~2100 nm with a -30-dB spectral width of ~1200 nm and 50% optical to optical conversion efficiency. The seed laser produces picosecond pulses with 1 MHz repetition rate at the wavelength of 1060 nm. After multi-stage amplification in ytterbium-doped fibers, the average output power is scaled to 54.51 W and 56.79 W respectively for LP11 and LP01 mode, accompanying supercontinuum generation. Obvious difference of supercontinuum generation between the LP01 and LP11 modes is experimentally observed due to the different dispersion characters.

Hybrid pumped gain-switched thulium fiber laser at a high repetition rate.

A gain-switched all-fiber thulium laser at 2μm with high repetition rate has been demonstrated under a hybrid pumping scheme combined of a pulsed pump at 1.56μm and CW pump at 793nm. The in-band pulsed pump at 1.56μm triggers the gain-switching pulses while the CW pump at 793nm facilitates the energy storage. Therefore, the seed cavity delivers high energy pulses allowing the elimination of multistage amplification. Such hybrid pump configuration is effective for generating gain-switched pulses of high average power with better slope efficiency and pulse width of a few hundreds of a nanosecond. The optimized cavity under such hybrid pump configuration provides output power of 5.92W from the gain-switched oscillator with slope efficiency of 60% and pulse width of 300ns at a repetition rate of 344kHz. Maximum pulse energy of 17.2μJ and peak power of 53.9W has been achieved at this repetition rate. Stable gain-switched pulses at reduced pump pulse energy have been achieved by the use of a CW pump at 793nm. This novel pump configuration facilitates gain switch at higher repetition rates where enough pump pulse energy may not be available. The gain-switched laser also operates at 520kHz and 1.3MHz repetition rate by changing the 1.56μm pulsed pump and cavity length.

Development of BCPDA-Eu3+-BAS labeled hepatitis B surface antibodies

The effect of the chelating agent 4,7-bis(chlorosulfophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BCPDA) labeled hepatitis B surface antibodies(HBsAb) on time-resolved fluoroimmunoassays(TRFIA) was investigated. The labeling detection method was established. The biotin-streptavidin(BAS) system was introduced, and the multi-stage amplification effect of the BAS system was analyzed. It is found that the BCPDA-Eu3+-HBsAb-BAS fluorescent marker can emit strong fluorescence. Compared to BCPDA-Eu3+-HBsAb, BCPDA-Eu3+-HBsAb-BAS demonstrates an enhanced fluorescence intensity by over 10 times. This study provides a guidance for the next generation non-radio immunoassays in clinical diagnosis.

Multi-GEM Detectors in High Particle Fluxes

Gaseous Electron Multipliers (GEM) are well known for stable operation at high particle fluxes. We present a study of the intrinsic limits of GEMdetectors when exposed to very high particle fluxes of the order of MHz/mm2. We give an interpretation to the variations of the effective gain, which, as a function of the particle flux, first increases and then decreases. We also discuss the reduction of the ion back-flow with increasing flux. We present measurements and simulations of a triple GEM detector, describing its behaviour in terms of accumulation of positive ions that results in changes of the transfer fields and the amplification fields. The behaviour is expected to be common to all multi-stage amplification devices where the efficiency of transferring the electrons from one stage to the next one is not 100%.

Adaptive pre-amplification pulse shaping in a high-power, coherently combined fiber laser system.

We report on the successful implementation of an adaptive pre-amplification pulse shaping technique in a high-power, coherently combined fiber laser system to achieve sub-300-fs pulse durations at 320W average power and 3.2mJ pulse energy. The pulse shaper is utilized to impose a gain flattening mask to increase the spectral width of the amplified pulse by 60%. Simultaneously, it pre-compensates the spectral phase acquired in the multi-stage amplification and subsequent compression including the eight-channel, coherently combined main amplification stage. This result does significantly enhance the performance of the fiber laser system and the subsequent nonlinear compression stages.