Jump to Content
View Cart
Top 20 Most Read Articles
February 2008
The 20 articles with the most full-text downloads during the month, in descending order.
 |
WSXM: A software for scanning probe microscopy and a tool for nanotechnology Rev. Sci. Instrum. 78, 013705 (2007); http://dx.doi.org/10.1063/1.2432410 (8 pages) Online Publication Date: 31 January 2007
Full Text:
Read Online (HTML)
|
Download PDF
|
|||
|
Show Abstract
In this work we briefly describe the most relevant features of WSXM, a freeware scanning probe microscopy software based on MS-Windows. The article is structured in three different sections: The introduction is a perspective on the importance of software on scanning probe microscopy. The second section is devoted to describe the general structure of the application; in this section the capabilities of WSXM to read third party files are stressed. Finally, a detailed discussion of some relevant procedures of the software is carried out.
|
||||
|
Show PACS
|
||||
|
|
Novel instrument for surface plasmon polariton tracking in space and time Rev. Sci. Instrum. 79, 013704 (2008); http://dx.doi.org/10.1063/1.2825463 (10 pages) Online Publication Date: 10 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
|||||||||||||
|
Show Abstract
We describe the realization of a phase-sensitive and ultrafast near-field microscope, optimized for investigation of surface plasmon polariton propagation. The apparatus consists of a homebuilt near-field microscope that is incorporated in Mach-Zehnder-type interferometer which enables heterodyne detection. We show that this microscope is able to measure dynamical properties of both photonic and plasmonic systems with phase sensitivity.
|
||||||||||||||
|
Show PACS
|
||||||||||||||
|
|
Rev. Sci. Instrum. 79, 011101 (2008); http://dx.doi.org/10.1063/1.2823259 (16 pages) Online Publication Date: 23 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
|||
|
Show Abstract
An overview of the developments postcirca 1980s in the instrumentation and application of charge exchange neutral particle diagnostics on magnetic fusion energy experiments is presented. First, spectrometers that employ only electric fields and hence provide ion energy resolution but not mass resolution are discussed. Next, spectrometers that use various geometrical combinations of both electric and magnetic fields to provide both energy and mass resolutions are reviewed. Finally, neutral particle diagnostics based on utilization of time-of-flight techniques are presented.
|
||||
|
Show PACS
|
||||
|
|
Compact electron beam ion sources/traps: Review and prospects (invited) Rev. Sci. Instrum. 79, 02A703 (2008); http://dx.doi.org/10.1063/1.2804901 (5 pages) Online Publication Date: 6 February 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
The Dresden electron beam ion trap (EBIT)/electron beam ion source (EBIS) family are very compact and economically working table-top ion sources. We report on the development of three generations of such ion sources, the so-called Dresden EBIT, Dresden EBIS, and Dresden EBIS-A, respectively. The ion sources are classified by different currents of extractable ions at different charge states and by the x-ray spectra emitted by the ions inside the electron beam. We present examples of x-ray measurements and measured ion currents extracted from the ion sources at certain individual operating conditions. Ion charge states of up to Xe48+ but also bare nuclei of lighter elements up to nickel have been extracted. The application potential of the ion sources is demonstrated via proof-of-concept applications employing an EBIT in a focused ion beam (FIB) column or using an EBIT for the production of nanostructures by single ion hits. Additionally we give first information about the next generation of the Dresden EBIS series. The so-called Dresden EBIS-SC is a compact and cryogen-free superconducting high-B-field EBIS for high-current operation.
|
|||
|
Show PACS
|
|||
|
|
Cantilever transducers as a platform for chemical and biological sensors Rev. Sci. Instrum. 75, 2229 (2004); http://dx.doi.org/10.1063/1.1763252 (25 pages) Online Publication Date: 21 June 2004
Full Text:
|
Download PDF
|
||
|
Show Abstract
Since the late 1980s there have been spectacular developments in micromechanical or microelectro-mechanical (MEMS) systems which have enabled the exploration of transduction modes that involve mechanical energy and are based primarily on mechanical phenomena. As a result an innovative family of chemical and biological sensors has emerged. In this article, we discuss sensors with transducers in a form of cantilevers. While MEMS represents a diverse family of designs, devices with simple cantilever configurations are especially attractive as transducers for chemical and biological sensors. The review deals with four important aspects of cantilever transducers: (i) operation principles and models; (ii) microfabrication; (iii) figures of merit; and (iv) applications of cantilever sensors. We also provide a brief analysis of historical predecessors of the modern cantilever sensors. © 2004 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
Phase-locked laser system for use in atomic coherence experiments Rev. Sci. Instrum. 79, 013104 (2008); http://dx.doi.org/10.1063/1.2823330 (8 pages) Online Publication Date: 11 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
|||||||||||
|
Show Abstract
We describe a phase-coherent laser system designed for use in experiments involving coherently prepared atomic media. We implement a simple technique based on a sample-and-hold circuit together with a reset of the integrating electronics that makes it possible to scan continuously the relative frequency between the lasers of over tens of gigahertz while keeping them phase locked. The system consists of three external-cavity diode lasers operating around 795 nm. A low-power laser serves as a frequency reference for two high-power lasers which are phased locked with an optical phase-locked loop. We measured the residual phase noise of the system to be less than 0.04 rad2. In order to show the application of the system towards atomic coherence experiments, we used it to implement electromagnetically induced transparency in a rubidium vapor cell and obtained a reduction in the absorption coefficient of 92%.
|
||||||||||||
|
Show PACS
|
||||||||||||
|
|
Femtosecond pulse shaping using spatial light modulators Rev. Sci. Instrum. 71, 1929 (2000); http://dx.doi.org/10.1063/1.1150614 (32 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
We review the field of femtosecond pulse shaping, in which Fourier synthesis methods are used to generate nearly arbitrarily shaped ultrafast optical wave forms according to user specification. An emphasis is placed on programmable pulse shaping methods based on the use of spatial light modulators. After outlining the fundamental principles of pulse shaping, we then present a detailed discussion of pulse shaping using several different types of spatial light modulators. Finally, new research directions in pulse shaping, and applications of pulse shaping to optical communications, biomedical optical imaging, high power laser amplifiers, quantum control, and laser-electron beam interactions are reviewed. © 2000 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
Calibration of atomic‐force microscope tips Rev. Sci. Instrum. 64, 1868 (1993); http://dx.doi.org/10.1063/1.1143970 (6 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
Images and force measurements taken by an atomic‐force microscope (AFM) depend greatly on the properties of the spring and tip used to probe the sample’s surface. In this article, we describe a simple, nondestructive procedure for measuring the force constant, resonant frequency, and quality factor of an AFM cantilever spring and the effective radius of curvature of an AFM tip. Our procedure uses the AFM itself and does not require additional equipment. |
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 79, 013101 (2008); http://dx.doi.org/10.1063/1.2827517 (4 pages) Online Publication Date: 2 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
We discuss a simple time of flight technique for measurement of temperature of a cold cloud in a magneto-optical trap (MOT). The technique is based on spatiotemporal fluorescence imaging of the cloud that is allowed to undergo one-dimensional expansion in the presence of the orthogonal two-dimensional configuration of laser beams by temporal modulation of a pair of counterpropagating trapping beams in the MOT. We show that, in the time scale 0 ⩽ t<5 ms, the expansion of the cloud is ballistic and the temperature can be extracted from the time variation of the rms size of the cloud in the expansion direction. The reliability of the technique has been established by comparing the results with release and recapture method, and also by fitting them to the known temperature scaling law.
|
|||
|
Show PACS
|
|||
|
|
A simple method for producing flattened atomic force microscopy tips Rev. Sci. Instrum. 79, 016103 (2008); http://dx.doi.org/10.1063/1.2834875 (2 pages) Online Publication Date: 18 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
We describe a simple and reliable procedure for obtaining a flat plateau on top of standard silicon nitride atomic force microscopy tips by scanning them over the focus of a high-numerical-aperture objective illuminated by near-infrared ultrashort laser pulses. Flattened tips produced this way exhibit a plateau that is parallel to the substrate when the cantilever is mounted. They represent a valid and cost-effective alternative to commercially available plateau tips.
|
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 79, 025102 (2008); http://dx.doi.org/10.1063/1.2839019 (7 pages) Online Publication Date: 7 February 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Our previous study of the particle mass sensor has shown a large ratio (up to thousands) between the spring constants of a rectangular cantilever in higher mode vibration and at the static bending or natural mode vibration. This has been proven by us through the derived nodal point position equation. That solution is good for a cantilever with the free end in noncontact regime and the probe shifted from the end to an effective section and contacting a soft object. Our further research shows that the same nodal position equation with the proper frequency equations may be used for the same spring constant ratio estimation if the vibrating at higher mode cantilever’s free end has a significant additional mass clamped to it or that end is in permanent contact with an elastic or hard measurand object (reference cantilever). However, in the latter case, the spring constant ratio is much smaller (in tens) than in other mentioned cases at equal higher (up to fourth) vibration modes. We also present the spring constant ratio for a vibrating at higher eigenmode V-shaped cantilever, which is now in wide use for atomic force microscopy. The received results on the spring constant ratio are in good (within a few percent) agreement with the theoretical and experimental data published by other researchers. The knowledge of a possible spring constant transformation is important for the proper calibration and use of an atomic force microscope with vibrating cantilever in the higher eigenmodes for measurement and imaging with enlarged resolution.
|
|||
|
Show PACS
|
|||
|
|
Two-axis probing system for atomic force microscopy Rev. Sci. Instrum. 79, 023705 (2008); http://dx.doi.org/10.1063/1.2841805 (5 pages) Online Publication Date: 14 February 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
A novel two-axis probing system is proposed for multiaxis atomic force microscopy (AFM). It employs a compliant manipulator that is optimally designed in terms of geometries and kinematics, and is actuated by multiple magnetic actuators to simultaneously control tip position and change tip orientation to achieve greater accessibility of the sample surface when imaging surfaces having large geometric variations. It leads to the creation of a multiaxis AFM system, which is a three-dimensional surface tool rather than a two-dimensional planar surface tool. The use of the system to scan the bottom corner of a grating step is reported.
|
|||
|
Show PACS
|
|||
|
|
Methods of single-molecule fluorescence spectroscopy and microscopy Rev. Sci. Instrum. 74, 3597 (2003); http://dx.doi.org/10.1063/1.1589587 (23 pages) Online Publication Date: 23 July 2003
Full Text:
|
Download PDF
|
||
|
Show Abstract
Optical spectroscopy at the ultimate limit of a single molecule has grown over the past dozen years into a powerful technique for exploring the individual nanoscale behavior of molecules in complex local environments. Observing a single molecule removes the usual ensemble average, allowing the exploration of hidden heterogeneity in complex condensed phases as well as direct observation of dynamical state changes arising from photophysics and photochemistry, without synchronization. This article reviews the experimental techniques of single-molecule fluorescence spectroscopy and microscopy with emphasis on studies at room temperature where the same single molecule is studied for an extended period. Key to successful single-molecule detection is the need to optimize signal-to-noise ratio, and the physical parameters affecting both signal and noise are described in detail. Four successful microscopic methods including the wide-field techniques of epifluorescence and total internal reflection, as well as confocal and near-field optical scanning microscopies are described. In order to extract the maximum amount of information from an experiment, a wide array of properties of the emission can be recorded, such as polarization, spectrum, degree of energy transfer, and spatial position. Whatever variable is measured, the time dependence of the parameter can yield information about excited state lifetimes, photochemistry, local environmental fluctuations, enzymatic activity, quantum optics, and many other dynamical effects. Due to the breadth of applications now appearing, single-molecule spectroscopy and microscopy may be viewed as useful new tools for the study of dynamics in complex systems, especially where ensemble averaging or lack of synchronization may obscure the details of the process under study. © 2003 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 78, 121301 (2007); http://dx.doi.org/10.1063/1.2821148 (15 pages) Online Publication Date: 12 December 2007
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Experimental and theoretical aspects of obtaining the magnetic information carried by laser beams diffracted from an array of micro- or nanosized magnetic objects are reviewed. We report on the fundamentals of vector magneto-optic Kerr effect (MOKE), Bragg-MOKE, and second-order effects in the Kerr signal in longitudinal Kerr geometry as well as on an experimental setup used for vector and Bragg-MOKE experiments. The vector and Bragg-MOKE technique in combination with micromagnetic simulation is a reliable tool for measuring the complete magnetization vector and for characterizing the reversal mechanism of lateral magnetic nanostructures. We discuss the Bragg-MOKE effect for three standard domain configurations during the magnetization reversal process and present the expected behavior of the magnetic hysteresis loops.
|
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 79, 013107 (2008); http://dx.doi.org/10.1063/1.2834877 (9 pages) Online Publication Date: 24 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
We describe an ultrasensitive pump-probe spectrometer for transient absorption measurements in the gas phase and in solution. The tunable UV pump and the visible (450–740 nm) probe pulses are generated by two independently tunable noncollinear optical parametric amplifiers, providing a temporal resolution of 20 fs. A homebuilt low gain photodetector is used to accommodate strong probe pulses with a shot noise significantly lower than the overall measurement noise. A matched digitizing scheme for single shot analysis of the light pulses at kilohertz repetition rates that minimizes the electronic noise contributions to the transient absorption signal is developed. The data processing scheme is optimized to yield best suppression of the laser excess noise and thereby transient absorbance changes down to 1.1×10−6 can be resolved. A collinear focusing geometry optimized for a 50 mm interaction length combined with a heatable gas cell allows us to perform measurements on substances with low vapor pressures, e.g., on medium sized molecules which are crystalline at room temperature. As an application example highlighting the capability of this instrument, we present the direct time-domain observation of the ultrafast excited state intramolecular proton transfer of 2-(2′-hydroxyphenyl)benzothiazole in the gas phase. We are able to compare the resulting dynamics in the gas phase and in solution with a temporal precision of better than 5 fs.
|
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 76, 061101 (2005); http://dx.doi.org/10.1063/1.1927327 (12 pages) Online Publication Date: 26 May 2005
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Nanoelectromechanical systems (NEMS) are drawing interest from both technical and scientific communities. These are electromechanical systems, much like microelectromechanical systems, mostly operated in their resonant modes with dimensions in the deep submicron. In this size regime, they come with extremely high fundamental resonance frequencies, diminished active masses,and tolerable force constants; the quality (Q) factors of resonance are in the range Q ∼ 103–105—significantly higher than those of electrical resonant circuits. These attributes collectively make NEMS suitable for a multitude of technological applications such as ultrafast sensors, actuators, and signal processing components. Experimentally, NEMS are expected to open up investigations of phonon mediated mechanical processes and of the quantum behavior of mesoscopic mechanical systems. However, there still exist fundamental and technological challenges to NEMS optimization. In this review we shall provide a balanced introduction to NEMS by discussing the prospects and challenges in this rapidly developing field and outline an exciting emerging application, nanoelectromechanical mass detection.
|
|||
|
Show PACS
|
|||
|
|
Time‐of‐Flight Mass Spectrometer with Improved Resolution Rev. Sci. Instrum. 26, 1150 (1955); http://dx.doi.org/10.1063/1.1715212 (8 pages) Online Publication Date: 29 December 2004
Full Text:
|
Download PDF
|
||
|
Show Abstract
A new type of ion gun is described which greatly improves the resolution of a nonmagnetic time‐of‐flight mass spectrometer. The focusing action of this gun is discussed and analyzed mathematically. The validity of the analysis and the practicability of the gun are demonstrated by the spectra obtained. The spectrometer is capable of measuring the relative abundance of adjacent masses well beyond 100 amu. |
|||
|
|
A calibration method for lateral forces for use with colloidal probe force microscopy cantilevers Rev. Sci. Instrum. 79, 023701 (2008); http://dx.doi.org/10.1063/1.2836327 (11 pages) Online Publication Date: 1 February 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
A calibration method is described for colloidal probe cantilevers that enables friction force measurements obtained using lateral force microscopy (LFM) to be quantified. The method is an adaptation of the lever method of Feiler et al. [
A. Feiler, P. Attard, and I. Larson, Rev. Sci. Instum. 71, 2746 (2000)
] and uses the advantageous positioning of probe particles that are usually offset from the central axis of the cantilever. The main sources of error in the calibration method are assessed, in particular, the potential misalignment of the long axis of the cantilever that ideally should be perpendicular to the photodiode detector. When this is not taken into account, the misalignment is shown to have a significant effect on the cantilever torsional stiffness but not on the lateral photodiode sensitivity. Also, because the friction signal is affected by the topography of the substrate, the method presented is valid only against flat substrates. Two types of particles, 20 μm glass beads and UO3 agglomerates attached to silicon tapping mode cantilevers were used to test the method against substrates including glass, cleaved mica, and UO2 single crystals. Comparisons with the lateral compliance method of Cain et al. [
R. G. Cain, S. Biggs, and N. W. Page, J. Colloid Interface Sci. 227, 55 (2000)
] are also made.
|
|||
|
Show PACS
|
|||
|
|
Rev. Sci. Instrum. 75, 2787 (2004); http://dx.doi.org/10.1063/1.1785844 (23 pages) Online Publication Date: 2 September 2004
Full Text:
|
Download PDF
|
||
|
Show Abstract
Since their invention just over 20 years ago, optical traps have emerged as a powerful tool with broad-reaching applications in biology and physics. Capabilities have evolved from simple manipulation to the application of calibrated forces on—and the measurement of nanometer-level displacements of—optically trapped objects. We review progress in the development of optical trapping apparatus, including instrument design considerations, position detection schemes and calibration techniques, with an emphasis on recent advances. We conclude with a brief summary of innovative optical trapping configurations and applications. |
|||
|
Show PACS
|
|||
|
|
Calibration of rectangular atomic force microscope cantilevers Rev. Sci. Instrum. 70, 3967 (1999); http://dx.doi.org/10.1063/1.1150021 (3 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
A method to determine the spring constant of a rectangular atomic force microscope cantilever is proposed that relies solely on the measurement of the resonant frequency and quality factor of the cantilever in fluid (typically air), and knowledge of its plan view dimensions. This method gives very good accuracy and improves upon the previous formulation by Sader et al. [Rev. Sci. Instrum. 66, 3789 (1995)] which, unlike the present method, requires knowledge of both the cantilever density and thickness. © 1999 American Institute of Physics. |
|||
|
Show PACS
|
|||
This Publication
Scitation
Google Scholar
PubMed