With every new release of LabOne®, a range of additional functionalities expands your instrument's capabilities while maintaining the quality standards associated with Zurich Instruments. This page summarizes some of LabOne's most significant features.
Window functions for controlling spectral leakage
Spectral leakage often occurs when temporal signals are analyzed in the frequency domain using the Fourier transform. This is due to the limited signal span over the temporal axis and can be mitigated by tapering the signal with temporal window functions. Symmetric window functions such as the Rectangular, Hamming, Hann, and Blackman-Harris windows are used widely as they provide different levels of trade-off between dynamic range and frequency resolution. From LabOne 22.02 onwards the Flat Top window also features in the Scope, DAQ and Spectrum Analyzer tools of LabOne, thus adding one more choice for spectral-leakage control when analyzing a signal in the frequency domain. In particular, the Flat Top window minimizes scalloping loss, which is desirable if the amplitude of sine signals is obtained from their spectral components.
The GIF shows the Spectrum Analyzer of LabOne where different symmetric and asymmetric window functions can be selected to reach an optimal balance between dynamic range and frequency resolution.
Supporting 64-bit ARM processors
ARM-based processors are becoming more powerful and thus more important to consider among available computers. From release 21.08 onwards, LabOne supports 64-bit ARM processors (characterized by the AArch64 or ARM64 architecture). This means that users can control Zurich Instruments' hardware using ARM-based computers such as a Raspberry Pi with a 64-bit Linux distribution. In addition to the Data Server and the Web Server, LabOne 21.08 provides APIs for C and Python to support the ARM64 architecture. Further, with release 21.08 LabOne supports macOS through a universal binary that is build to be natively compatible with Apple Silicon M-series processors.
The image to the right shows how a Raspberry Pi computer runs the LabOne software to control the MFLI Lock-in Amplifier and acquire measurement data: while the LabOne Web Server prepares the oscilloscope data for the graphical user interface (GUI), the Python API gets the signals measured by the instrument’s demodulator.
Nyquist and Bode Plots
When measuring the frequency response of a sample, whether it is the transfer function of a resonator or the impedance of an electrical circuit, you are often interested in acquiring Bode and Nyquist plots in parallel. The Bode plot (see top figure) shows the amplitude and phase of the sample response as a function of the applied frequency, whereas the Nyquist plot (see bottom figure) displays the imaginary part of the sample response versus its real part. Simultaneous acquisition of the two plots allows you to relate the critical points in one plot to the corresponding points in the other. With release 21.02, the XY plot in the Sweeper tool of LabOne enables you to draw Nyquist plots in parallel with Bode spectroscopy figures. The Nyquist plot can be configured freely, and its scales can be locked with the so-called 'track feature' to display the Nyquist plot in a true 1:1 ratio.
When you need to extract features from the raw data you acquire and to follow the temporal evolution of a measured signal, postprocessing of your data is often the adopted strategy – and yet that does not occur in real-time, making it difficult to tune the experimental setup online while looking at the outcome. The Trends feature included in the LabOne 20.07 release allows you to visualize signal features from the raw measurements through real-time signal processing. For example, the Trends plot (see bottom graph) tracks the delay and the peak of a recorded pulse in the Scope (see top graph): this reveals a linear sweep (orange curve) for the delay and a quadratic trend (green curve) for the peak value. The Scope, Plotter, Spectrum Analyzer, and DAQ tools all benefit from this integrated Trends feature.
The low-pass filter within the demodulator of a lock-in amplifier allows you to remove undesired frequency components from your signal. If the filter bandwidth is too wide, the frequency components leak out of the filter and determine a bowl-shaped histogram for the signal described by an arcsine distribution. For a properly adjusted filter, the histogram follows a bell-shaped normal distribution. With the Histogram Fit tool included in LabOne 20.07, it is possible to fit the measured histogram to both arcsine and Gaussian distributions (see figure). This means that you can monitor the leakage through the filter and adjust the filter bandwidth to ensure that the histogram follows a normal distribution. The fitting errors in the Math tab indicate how close your measurement is to an ideal scenario.
It happens frequently that a noisy signal has a linear trend and you are interested to extract the slope and intercept of the trend out of the fluctuations. For instance, you may increase the intensity of light shining on a photodiode and measure its generated current to obtain its responsivity, given by the slope of the current as a function of power in the small-signal regime. Another example is that of a frequency component hidden in your signal, where the frequency is deduced from the slope of the measured phase versus time. In LabOne 20.01, the Sweeper and DAQ tabs are equipped with a linear fitting tool that computes the slope, intercept and quality of linearity (given by the coefficient of determination R2) as shown to the left.
Did you know that the statistical behavior of the signal amplitude R is captured by a Rice distribution, whereas the quadrature components X and Y follow a Gaussian (normal) distribution when the correct measurement is carried out? In LabOne 20.01, the measured histogram is fitted to the expected model to compare the outcome of your measurement with an ideal scenario. The real-time calculated parameters, especially the fitting error coefficient, indicate how well the instrument's settings (such as the filter time-constant) are adjusted. The measured histogram can also be saved as shown to the right.
In superconducting quantum computing, the state of measured qubits is often represented in the complex plane: the real axis shows the in-phase component I, whereas the imaginary axis displays the quadrature component Q of the readout signals. As shown to the left, LabOne 20.01 can visualize complex data on the I/Q plane and carry out rotation, translation and dilation operations on the measured points to provide better visibility and facilitate complex thresholding.
Waterfall Display and Triggered Spectrum Analysis
The LabOne Spectrum Analyzer is a powerful tool to analyze measurement signals in the frequency domain, helping in the measurement of sidebands, in quantifying multiple signal components, or in characterizing various noise sources. You can zoom into sub-Hertz features even on signals in the hundreds of MHz.
This widely applicable tool notably features a waterfall display or spectrogram, facilitating the analysis of spectra that evolve over time. In addition, it is possible to perform triggered acquisitions of multiple spectra with precise timing and display the results as 2-dimensional color plots. The triggered data acquisition is provided by the LabOne Data Acquisition (DAQ) tool, which was originally reworked from a previous module called Software Trigger.
These features are of great relevance to measurements of transient phenomena such as free induction decay (FID) in NMR spectroscopy. Triggered acquisition is particularly useful on the UHFLI with the UHF-AWG Arbitrary Waveform Generator option installed. Such a system combines pulse generation, synchronized acquisition, and powerful software for time- and frequency-domain analysis, making it the perfect tool for pulsed measurements.
Q-factor Extraction from Sweeper Data
In applications such as MEMS, AFM, gyroscopes, sensors, etc., the Q-factor of resonators is required to establish a closed-loop control system such as a PLL following the resonance track of a tuning fork. Moreover, the Q-factor determines the damping characteristics of oscillators such as lasers and clock generators. Therefore, it is essential to extract the resonator Q-factor rapidly and accurately from its measured frequency response. The Sweeper module in LabOne offers a mathematical tool for Q-factor extraction. By measuring the frequency response of a resonator, it is possible to set the cursors around the peak and add the resonance parameters in the Math tab. As depicted in the figure, the tool fits the measured curve (solid line) to a Lorentzian model (dashed line) and extracts the resonator parameters including the quality factor, resonance frequency, -3 dB, or FWHM bandwidth for both amplitude and phase independently.
Multi-Device Synchronization (MDS)
Starting with LabOne release 17.06, users operating several Zurich Instruments products simultaneously can synchronize their instruments and use them through a single instance of LabOne.
Applications requiring multiple synchronized signal input and signal output channels benefit from multi-device synchronization (MDS), which provides clock synchronization and time-stamp alignment. MDS also enables you to orchestrate the entire instrument assembly through a single user interface or API session.
The following signal generation and data acquisition tools are MDS-ready:
- AWG: control the output channels of several AWG devices from a single sequencer along with sample-wise synchronization of all output waveforms.
- Sweeper: sweep a parameter on one instrument, and acquire and plot data from multiple instruments in a single figure simultaneously.
- Plotter: align and analyze the measurements performed on multiple instruments in a single Plotter window.
- Data Acquisition: trigger on any signal and acquire shots of aligned data from multiple instruments into a single image construction window.
- Continuous recording of aligned data: acquire fully synchronized lock-in, boxcar, PID, Arithmetic Unit and Scope data from multiple instruments.
Imaging with the Data Acquisition Module
Imaging is one of the most important applications for our customers working in Scanning Probe Microscopy (SPM) and non-linear imaging (with CARS, SRS, and THz spectroscopy being prominent examples).
The imaging mode converts any of the measurement signals into images and provides:
- A clear definition of a "line", based on a starting event detected by the line trigger and a user-defined duration.
- The resampling of the recorded data samples to the required number of pixels with a suitable interpolation and/or averaging.
- To store the matrix-like data in a grid data structure, based on the number of defined lines.
All this is implemented in the LabOne Data Acquisition tool (DAQ), and is available in the user interface as well as on the APIs. With the power to stream up to a sustainable 800 kSa/s over multiple channels in a triggered fashion (depending on product category), the LabOne server architecture is strong in its data acquisition capability: even video rates (512*512 pixel/s) are well below the transfer rate limit.
Graphical Lock-in Tab – Functional Block Diagram
Thanks to the functional block diagram for every demodulator in the LabOne user interface, it is possible to intuitively understand the signal processing pathways.
For LabOne users, the File Manager brings the advantage of a quick and easy access to measurement files, settings files, and log files on the local PC. Moreover, MFLI users can manage files on the instrument's flash drive as well as on storage devices attached to one of the two USB connectors.
The UHFLI and the MFLI can be programmed to start up in a user-defined state of operation. This is particularly interesting for applications where the same instrument configuration is always needed, and results are mainly taken out from the auxiliary outputs. Typical examples are imaging applications with analog interfacing to the main controller.
Check the LabOne Compatibility page before proceeding with an installation or a software update.