- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Tailoring Single-Frequency VECSELs for Quantum Technology Applications
摘要： Many quantum technology applications, such as quantum information processing, precision metrology, and atomic clocks, rely on lasers at many different wavelengths with demanding characteristics in terms of power, linewidth, beam quality, and intensity noise. These lasers are typically used to detect or change the quantum states of neutral atoms and ions. Besides the need for precisely defined features fitting a specific atom/ion system, there is an increasing need to make such lasers more affordable, as well as easier to use and tailor, in order to ensure faster transit from lab to real applications. Vertical-External-Cavity Surface-Emitting Lasers (VECSELs, aka. OPSLs or SDLs) are optically pumped semiconductor lasers that combine the benefits of semiconductor quantum well -lasers; the wavelength versatility and the wide pump absorption bandwidth, with the benefits of diode-pumped solid-state lasers; the high output power and excellent beam quality. The external cavity geometry of VECSELs enables the insertion of intracavity wavelength selective elements for tunable single-frequency operation, and the insertion of nonlinear crystals for efficient intracavity frequency conversion. These features make VECSELs very promising candidates to address the needs of quantum technology and other high impact applications. We present compact turnkey single-frequency VECSELs tailored for quantum technology applications, for generation and manipulation of trapped ions for quantum computing. Our previous demonstration was focused on VECSEL-based systems at 279.6 nm for Doppler cooling and at 285.3 nm for photoionization of magnesium ions. Here, we focus on wavelength extension and tailoring the single-frequency operation for use with several other promising ions, such as beryllium at 313 nm and 235 nm. We present very recent results of Watt-level single-frequency emission at challenging 1252 nm and 940 nm wavelengths, which are prerequisites for high power emission at 313 nm and 235 nm, as well as recent developments on the laser platform. We believe that VECSELs can potentially replace many of the laser systems currently in use and enable new quantum technology applications.
关键词： single-frequency lasers,VECSELs,quantum computing,quantum technology,trapped ions
更新于2025-09-12 10:27:22
-
Production of highly charged ions of rare species by laser-induced desorption inside an electron beam ion trap
摘要： This paper reports on the development and testing of a novel, highly efficient technique for the injection of very rare species into electron beam ion traps (EBITs) for the production of highly charged ions (HCI). It relies on in-trap laser-induced desorption of atoms from a sample brought very close to the electron beam resulting in a very high capture efficiency in the EBIT. We have demonstrated a steady production of HCI of the stable isotope 165Ho from samples of only 1012 atoms (～300 pg) in charge states up to 45+. HCI of these species can be subsequently extracted for use in other experiments or stored in the trapping volume of the EBIT for spectroscopic measurements. The high efficiency of this technique extends the range of rare isotope HCIs available for high-precision atomic mass and spectroscopic measurements. A first application of this technique is the production of HCI of the synthetic radioisotope 163Ho for a high-precision measurement of the QEC-value of the electron capture in 163Ho within the “Electron Capture in Holmium” experiment [L. Gastaldo et al., J. Low Temp. Phys. 176, 876–884 (2014); L. Gastaldo et al., Eur. Phys. J.: Spec. Top. 226, 1623–1694 (2017)] (ECHo collaboration) ultimately leading to a measurement of the electron neutrino mass with an uncertainty on the sub electronvolt level.
关键词： high-precision atomic mass measurements,highly charged ions,spectroscopic measurements,rare isotopes,electron beam ion trap,laser-induced desorption
更新于2025-09-12 10:27:22
-
Fabrication & Characterization of Simple Structure Self-Assembled Graphene Oxide Based Heavy Metal Ion Sensor
摘要： The simple structure and high robustness of heavy metal sensors were developed by implementing a GO/Au/FR4 Substrate configuration. In this study, the sensing characteristics of an in-house fabricated heavy-metal-ion sensor (HMS) with graphene oxide (GO) as the sensing element was presented. The HMS employed a three electrodes configuration architecture, while GO of various concentrations ranging from 0.1 to 1 mg/ml would serve as the sensing medium. The surface of the working electrode was decorated with GO through drop-casting technique. Several types of heavy metal ions such as lead (Pb), mercury (Hg), and cadmium (Cd) were used in this study. The concentration of each was prepared according to the maximum exposure limit imposed by the World Health Organization, with Pb (10 ppm), Hg (1 ppm), and Cd (5 ppm). The sensing performance was found to be proportionate to GO concentration when the sensor was exposed to 10 ppm of Pb. On selectivity test using 1 mg/ml of GO, the sensor exhibited superior sensitivity towards 10 ppm of Pb, ～ 1666.6%; followed by 5 ppm of Cd, ～ 512.8%, while 1 ppm of Hg being the least detected, ～ 10.5%. This signified GO shows greater affinity towards Pb ions detection in comparison to others.
关键词： graphene oxide,sensors and working electrode,Electrochemical,IDE,heavy metal ions
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Development of an XUV Frequency Comb for Precision Spectroscopy of Highly Charged Ions
摘要： Highly charged ions (HCI) have a few tightly bound electrons and many interesting properties for probing fundamental physics and developing new frequency standards [1, 2]. Many optical transitions of HCI are located in the extreme ultraviolet (XUV) and conventional light sources do not allow to study these transistions with highest precision. For this reason, we are developing an XUV frequency comb by transfering the coherence and stability of a near infrared frequency comb to the XUV by means of high-harmonic generation (HHG) [3-4]. Reaching intensity levels necessary for HHG (～ 1013W/cm2), while operating at high repetition rates (100 MHz) for large comb line spacing, is challenging. Therefore, the laser pulses are ?rst ampli?ed in a rod-type ?ber to 70 W and compressed to sub-200 fs in a grating and prism compressor. Afterwards, pulses are resonantly overlapped in an astigmatism-compensated femtosecond enhancement cavity, which is locked to the frequency comb. To achieve high stability and low-noise performance, the cavity is built on a rigid titanium structure with vibrational decoupling from the vacuum pumps. High-harmonics will then be generated in a target gas in the tight focus of the cavity and coupled out of the cavity by minus-?rst order diffraction from a small-period grating etched into a high-re?ective cavity mirror [5]. Mirror degradation due to contamination and hydrocarbon aggregation is prevented by operating the whole cavity under ultra-high vacuum conditions. A differential pumping scheme will enable high target gas pressures in the laser focus without impairing the pressure elsewhere in the chamber [6]. Finally, the XUV light will be guided to trapped and sympathetically cooled HCI [7] in a cryogenic superconducting linear Paul trap to drive narrow transitions with individual comb lines. A schematic overview of the experiment is shown in Fig. 1. Recent progress and ?rst experiments with intra-cavity multiphoton ionization are presented.
关键词： femtosecond enhancement cavity,highly charged ions,precision spectroscopy,high-harmonic generation,XUV frequency comb
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Spectral Luminescence Properties of Ho <sup>3+</sup> Ions in Active Media Codoped with Tb <sup>3+</sup> , Pr <sup>3+</sup> and Yb <sup>3+</sup> for Mid-Infrared Laser Development
摘要： Lasers operating in mid-infrared spectral region specifically with 3 m wavelength attract a lot of attention due to their various applications in atmospheric monitoring, medical surgery, remote sensing and scientific research. Such laser can be used as an efficient and high-quality radiation source for optical parametric oscillators and converters to longer IR wavelengths. Laser active media doped with Ho3+ ions are of interest for obtaining the radiation in this spectral range. However the realization of the laser radiation at 5I6 → 5I7 optical transition in Ho3+ ions is a complicated task due to the lack of commercially available laser diodes for efficient pumping of Ho3+ ions. Yb3+ ion is known as an efficient sensitizer for Ho3+ ions in various laser active crystals. The scheme with the excitation transfer from Yb3+ to Ho3+ was realized in Cr:Yb:Ho:YSGG and Cr:Yb:Ho:Eu:YAP lasers with flash lamp pumping [1, 2] and Ho:Yb:GGG and Ho:Yb:YSGG lasers with diode pumping [3]. In addition 5I6 → 5I7 optical transition is known as a “self-terminating” one because the fluorescence lifetime of the lower laser level 5I7 is considerably larger than that of the upper laser level 5I6. Codoping of Ho3+ active media with Tb3+ or Pr3+ ions can accelerate the deactivation process of the lower laser level. The concentration set of CaF2 crystal doped with Ho3+, Yb3+, Tb3+, Pr3+ ions was grown using the Bridgman technique. The number of Gd2O3, Y2O3 single crystal fibers doped with the same ions was successfully obtained by laser-heated pedestal growth method. Absorption spectra of Yb:Ho:Gd2O3 and Yb:Ho:Pr:Gd2O3 crystals showed that Yb3+ doping increased the absorption coefficient within 850-1050nm spectral region and make Yb doped media suitable for efficient pumping by commercially available laser diodes. The fluorescence lifetime of 5I6 and 5I7 manifolds of Ho3+ ions was investigated in CaF2 crystals codoped with Tb3+ and Pr3+ ions. It was found that this codoping resulted in the depopulation of the lower laser level 5I7 in Ho3+ ions and at the same time had little influence on the upper laser level 5I6 (Table 1). The lifetime of the lower laser level reduced from 17.5 ms for Yb:Ho:CaF2 crystal to 0.75 ms for Yb:Ho:Tb:CaF2. Deactivation effect of lower laser level 5I7 in Ho3+ was also observed in Yb3+:Ho3+:Pr3+:Gd2O3 and Yb3+:Ho3+:Tb3+:Gd2O3 single crystal fibers. The lifetime of the lower laser level 5I7 decreased from 8.25 ms to 1.04 ms and to 0.67 ms with a codoping of 0.5 at.% Pr3+ and 0.5 at.% Tb3+ ions, respectively. The use of Yb3+, Tb3+ or Pr3+ codoping with Ho3+ to enhance the laser properties of Ho3+ ions at 5I6→5I7 optical transition at the wavelength of ~2.8-3 μm were investigated in the Gd2O3, Y2O3 single crystal fiber for the first time. Obtained results indicate that single crystal fiber Yb3+:Ho3+:Tb3+:Gd2O3 and CaF2 :Yb3+:Ho3+:Tb3+ crystal is a promising laser medium for developing compact LD-pumped lasers operating at the wavelength of 2.8-3 μm.
关键词： Pr3+ ions,Tb3+ ions,mid-infrared laser,fluorescence lifetime,laser active media,Ho3+ ions,Yb3+ ions
更新于2025-09-11 14:15:04
-
Internal Energy Deposition in Infrared Matrix-Assisted Laser Desorption Electrospray Ionization With and Without the Use of Ice as a Matrix
摘要： The internal energy deposited into analytes during the ionization process largely influences the extent of fragmentation, thus the appearance of the resulting mass spectrum. The internal energy distributions of a series of para-substituted benzyl pyridinium cations in liquid and solid-state generated by infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) were measured using the survival yield method, of which results were subsequently compared with conventional electrospray ionization (ESI). The comparable mean internal energy values (e.g., 1.8–1.9 eV at a collision energy of 15 eV) and peak widths obtained with IR-MALDESI and ESI support that IR-MALDESI are essentially a soft ionization technique where analytes do not gain considerable internal energy during the laser-induced desorption process and/or lose energy during uptake into charged electrospray droplets. An unusual fragment ion, protonated pyridine, was only found for solid IR-MALDESI at relatively high collision energies, which is presumably resulted from direct ionization of the pre-charged analytes in form of salts. Analysis of tissue with an ice layer consistently yielded ion populations with higher internal energy than its counterpart without an ice layer, likely due to a substantially enhanced number of IR absorbers with ice. Further measurements with holo-myoglobin show that IR-MALDESI-MS retains the noncovalently bound heme-protein complexes under both native-like and denaturing conditions, while complete loss of the heme group occurred in denaturing ESI-MS, showing that the softness of IR-MALDESI is equivalent or superior to ESI for biomolecules.
关键词： Ambient ionization,Survival yield method,Internal energy deposition,Mass spectrometry imaging,Thermometer ions,IR-MALDESI
更新于2025-09-11 14:15:04
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - UV Luminescence in Ho:ZBLAN Glasses
摘要： Compact, short-wavelength lasers are continuously considered as one of the most attractive among all coherent light sources. A very wide range of applications such as data storage, photolithography, medical diagnostics and sterilization motivates research and development on new active materials which can efficiently emit light in the UV spectral range. There are three general methods to achieve UV and visible light emission. The first are semiconductor-based LEDs and laser diodes - in the recent years a rapid progress in the field of semiconductor lasers has been observed resulting in a variety of commercially available short-wavelength laser diodes. These impressive devices, however, are not free from some disadvantages, like poor quality of the beam and limited output power. That’s why other sources continue to attract researchers’ attention. The second method deploys nonlinear crystals, which enable obtaining short wavelength emission by the frequency multiplication. The third way to achieve UV and visible light is to directly use the optical transitions within rare earth ions in solid state media [1-2]. This work is focused on this last method.
关键词： short-wavelength emission,Ho:ZBLAN glasses,optical spectroscopy,rare earth ions,UV luminescence
更新于2025-09-11 14:15:04
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Towards Continuous Variables Quantum Computing with Trapped Ions
摘要： The usually employed methods of using spin states of atomic-like systems for quantum information encoding suffer from scalability issues. For example, it becomes very challenging to control a large number of trapped atomic ions each representing a physical qubit. The alternative approach would be to exploit the large Hilbert space provided by a near-harmonic trapping potential and encode the information in the oscillator states. We use sideband-resolved addressing of motional states in a single trapped 171Yb ion to demonstrate a conditional beam splitter gate. The conditional beam splitter (CBS) Hamiltonian |e??e|(a?b + ab?) swaps the quantum states of two motional modes of a trapped ion, conditioned on the ion’s internal state. It thus can be viewed as a SWAP gate and we utilize it to demonstrate SWAP tests, implement single shot parity measurements, and generate maximally entangled NOON states of motion. We discuss the spurious phase shifts that prevent the gate to be dubbed as universal and show that with an addition of an ancilla vacuum mode, the conditional beam splitter gate in trapped ion system can be used to construct a universal exponential-SWAP gate that is required for practical algorithms such as matrix inversion and other interesting applications.
关键词： SWAP gate,conditional beam splitter gate,NOON states,quantum computing,trapped ions
更新于2025-09-11 14:15:04
-
A green luminescence of lemon derived carbon quantum dots and their applications for sensing of V5+ ions
摘要： A simple approach for the synthesis of luminescent carbon dots (C-dots) has been developed by the hydrothermal treatment of lemon juice as carbon precursor at 240 °C in 12 h. The obtained C-dots were found to emit bright green luminescence. Meanwhile, the C-dots exhibited excitation-dependence, photo-stability, and well dispersibility. The C-dots were used for detection of ion V5+ in water and serum, which was based on V5+ induced luminescence quenching of C-dots. The selectivity experiments revealed that the luminescent sensor was specific for V5+ ions even with interference by high concentrations of other metal ions. Detection limits for V5+ ions was 3.2 ppm. These results suggest that the present C-dots are potential application in optoelectronic, imaging and luminescent probing of V5+ ions.
关键词： Quantum dots,Nanoparticles,Luminescence,Metal ions,Carbon materials
更新于2025-09-11 14:15:04
-
Nd3+ Cluster Adjustment in Nd3+:CaNb2O6 by Co-doping La3+ Buffers for Improvement of Fundamental and Self-stimulated Raman Scattering Laser Operation: A Study Case from the Perspective of Defect Chemistry
摘要： The fluorescence quenching caused by Nd3+ clusters in Nd3+ doped crystal even at low Nd3+ concentration has restrained the performance of Nd3+ laser. In this work, Nd3+:CaNb2O6 and Nd3+:La3+:CaNb2O6 single crystals have been grown by the Czochralski method. RE3+ (RE3+=Nd3+, La3+) ion incorporation mechanisms, the formation of Nd3+ clusters, and the feasibility of La3+ ions as buffers in RE3+:CaNb2O6 crystal have been demonstrated and assessed by atomistic simulation methods. The spectral and laser properties of the Nd3+:CaNb2O6 and Nd3+:La3+:CaNb2O6 have been measured. All the results indicate the Nd3+ dimers with distances between Nd3+ close to the critical interaction distance have formed in the Nd3+:CaNb2O6 and the La3+ ions as buffers can alleviate the interaction of Nd3+ effectively in the Nd3+:La3+:CaNb2O6 as expected. Benefitting from the introducing of La3+ buffers, about 2.6 W fundament laser with slope efficiency of 36.5% and about 310 mW self-stimulated Raman scattering laser with conversion and slope efficiencies of 8.3% and 9.5%, respectively, which are superior to those of the Nd3+:CaNb2O6, have been achieved in the Nd3+:La3+:CaNb2O6.
关键词： laser,buffers ions,cluster adjustment,defect chemistry
更新于2025-09-11 14:15:04