Characterisation, Measurement & Analysis
+44(0)1582 764334

News

  • Optical Reflectometers – How Do They Compare?

    Measuring the return loss along a fibre optic network, or within a photonic integrated circuit, is a common and very important technique when characterising a network’s or device’s ability to efficiently propagate optical signals. Reflectometry is a general method of measuring this return loss and consists of launching a probe signal into the device or network, measuring the reflected light and calculating the ratio between the two.

    Spatially-resolved reflectometers can map the return loss along the length of the optical path, identifying and locating problems or issues in the optical path. There are three established technologies available for spatially-resolved reflectometry:

    • Optical Time-Domain Reflectometry (OTDR)
    • Optical Low-Coherence Reflectometry (OLCR)
    • Optical Frequency-Domain Reflectometry (OFDR)

    The OTDR is currently the most widely used type of reflectometer when working with optical fibre. OTDRs work by launching optical pulses into the optical fibre and measuring the travel time and strength of the reflected and backscattered light.These measurements are used to create a trace or profile of the returned signal versus length. OTDRs are particularly useful for testing long fibre optic networks, with ranges reaching hundreds of kilometres. The spatial resolution (the smallest distance over which it can resolve two distinct reflection events) is typically in the range of 1 or 2 meters. All OTDRs, even specialised ‘high-resolution’ versions, suffer from dead zones – the distance after a reflection in which the OTDR cannot detect or measure a second reflection event. These dead zones are most prevalent at the connector to the OTDR and any other strong reflectors. OLCR is an interferometer-based measurement that uses a wideband low-coherent light source and a tunable optical delay line to characterise optical reflections in a component. While an OLCR measurement can achieve high spatial resolution down to the tens of micrometers, the overall measurement range is limited, often to only tens of centimetres. Therefore, the usefulness of the OLCR is limited to inspecting individual components, such as fibre optic connectors.Finally, OFDR is an interferometer-based measurement that utilises a wavelength-swept laser source. Interference fringes generated as the laser sweeps are detected and processed using the Fourier transform, yielding a map of reflections as a function of the length. OFDR is well suited for applications that require a combination of high speed, sensitivity and resolution over short and intermediate lengths.Luna’s Optical Backscatter Reflectometers (OBRs) are a special implementation of OFDR, adding polarisation diversity and optical optimisation to achieve unmatched spatial resolution. An OBR can quickly scan a 30-meter fibre with a sampling resolution of 10 micrometers or a 2-kilometre network with 1-millimetre resolution.This graphic summarises the landscape of these established technologies for optical reflectometry. By mapping the measurement range and spatial resolution of the most common technologies, the plot illustrates the unique application coverage of OBR.

  • Lambda Photometrics are now the sole distributor for E.A. Fischione, Inc., for the UK and Ireland.

    A leading Manufacturer in the Electron Microscopy industry

    Eugene A. Fischione founded E.A. Fischione Instruments, Inc. in 1966. As a research machinist at the U.S. Steel Technical Centre (formerly U.S. Steel Research Centre) from 1956 to 1977, Eugene Fischione was involved with many of the early developments in electron microscopy. Today, Fischione strive to produce sophisticated electron microscopy sample preparation equipment shown by the trademarked names such as the PicoMill®  and NanoMill ®.

    The product range has developed a long way since 1966 and we can offer products from four different categories.

    Follow the hyperlinks to see more product related information:

    Conventional Sample Preparation

    Ion Beam Preparation

    Contamination Solutions

    TEM Holders

    To speak with a sales/applications engineers please call 01582 764334 or click here to email.

  • Vibration-Tolerant Interferometry

    QPSI™ Technology Shrugs Off Vibration from Common Sources

    When image stabilization became available on digital cameras, it vastly reduced the number of photos ruined by camera shake. The new technology eliminated the effects of common hand tremors, greatly improving image quality in many photo situations.

    Animated comparison of a PSI measurement with fringe print-through due to vibration, and the same surface measured with QPSI™ technology – free of noisy print-through.

    In precision interferometric metrology, a similar problem, environmental vibration, has ruined countless measurements, like the one in the animation shown at right. Vibration can significantly affect measurement results and spatial frequency analysis, and it is difficult to make high quality optics if you can not measure them reliably. Solving the vibration problem can be costly, requiring the purchase of a vibration isolation system or a special dynamic interferometer.

    ZYGO's QPSI™ technology is truly a breakthrough for many optical facilities because it eliminates problems due to common sources of vibration, providing reliable data the first time you measure. QPSI measurements require no special setup or calibration, and cycle times are typically within a second or two of standard PSI measurements.

    Key Features:

    • Eliminates ripple and fringe print-through due to vibration
    • High-precision measurement; same as phase-shifting interferometry (PSI)
    • Requires no calibration, and no changes to your setup
    • Easily enabled/disabled with a mouse click

    QPSI is available exclusively from ZYGO on Verifire™, Verifire™ HD, Verifire™ XL, and also on DynaFiz® interferometer systems that have the PMR option installed (phase measuring receptacle). These systems are easy-to-use, on-axis, common-path Fizeau interferometers – the industry standard for reliable metrology – making them the logical choice for most surface form measurements.

    QPSI™ Simplifies Production Metrology
    A ZYGO interferometer with QPSI technology is capable of producing reliable high-precision measurements in the presence of environmental vibration from common sources such as motors, pumps, blowers, and personnel. Unless your facility is free of these sources, your business will likely benefit from QPSI technology.

    While QPSI can completely solve many common vibration issues, environments that have extreme vibration and/or air turbulence may require the additional capability of DynaPhase® dynamic acquisition, which is included by default with ZYGO's DynaFiz® interferometer. DynaPhase® is also available as an option on most new Verifire systems from 2018 onwards.
    We can help determine the best solution for your particular situation.

    Click here to read further information on DynaPhase® Dynamic Acquisition for Extreme Environments Confidence in metrology, no matter the conditions.

    Please contact us for advice and a demonstration please call 01582 764334 or click here to email.

  • Dynamic Capability comes to (nearly) all new Zygo Verifire Interferometers

    DynaPhase® Dynamic Acquisition for Extreme Environments
    Confidence in metrology, no matter the conditions

    Fizeau Interferometry has become a trusted standard for precise metrology of optical components and systems. Traditionally, these instruments were required to be installed in lab environments, where conditions were carefully controlled, to ensure high precision measurements were not compromised. However, today a growing number of applications demand easy, cost-effective solutions for the use of interferometry in environments where metrology has been difficult or impossible in the past.

    Challenge
    Often, optical systems must be tested in locations that simulate their end-use environment. These environments can present challenges due to factors like large vibration and air turbulence, which can negatively affect or prevent the ability to acquire reliable optical measurements. Many of these challenges are addressed with less than optimal solutions, often suffering from drawbacks and issues related to usability, speed, reliability and precision.

    Solution
    ZYGO's patented DynaPhase® data acquisition technology offers many differentiated benefits, without the limitations associated with alternative methods. Key attributes of DynaPhase include:

    • Highest vibration tolerance in a Fizeau interferometer, enabled by the ZYGO-manufactured high-power laser* and fast acquisition speeds
    • Patented in-situ calibration enables the highest precision, lowest measurement uncertainty measurements, and excellent correlation to temporal phase shifting interferometry (PSI)
    • Simple setup and calibration compared to alternative approaches
    • Cost-effective solution; available on nearly all ZYGO laser interferometers

    Comparison of Measurement Techniques Using an Identical Measurement Cavity


    DynaPhase offers the versatility and performance to address a wide range of challenging optical testing environments and applications, including:

    • Cryogenic and vacuum chamber testing
    • Telescope components and complex optical systems
    • Large tower, workstations and complex or unstable test stands

    Features
    DynaPhase is available on nearly all ZYGO laser interferometers. Features vary by model and enable users the flexibility to use capabilities that enhance efficiency in Production Mode, enable fast system alignment with LivePhase, or reveal temporal changes in data with Movie Mode.


    Summary
    Get the most from your metrology investment with the unique capabilities and unmatched versatility of DynaPhase, now available on the entire interferometer line from ZYGO.
    Complete range of vibration tolerant metrology - check out ZYGO's patented QPSI vibration tolerant temporal phase shifting data acquisition enables metrology in the presence of common shop floor vibrations without the need for calibration.

    DynaPhase is inherent in the DynaFiz interferometer - and available as an optional extra software module on the new Verifire (1200 x 1200 pixel camera), Verifire HD and HDx systems. This means you can have DynaPhase capability on the entry level Verifire interferometer, which is pretty well specified to start with as it includes QPSI technology also.

    Click here to read further information on QPSI™ Technology Shrugs Off Vibration from Common Sources.

    To speak with a Sales & Applications Engineer please call 01582 764334 or click here to email.

  • SEM automation guidelines for small script development: simulation and reporting

    Scripts are small automated software tools that can help a scanning electron microscope (SEM) user work more efficiently. In my previous blogs, I have explained how we can use the Phenom SEM with the Phenom programmable interface (PPI) to automate the process of acquiring, analysing and evaluating images. In this blog, I will add the Phenom PPI simulator to that and explain how you can generate and export reports using PPI.

    First, I’ll explain how to create a Phenom SEM Simulator in PPI and how to use it to acquire images. The Simulator mimics the behaviour of the Phenom and is a great tool to develop code without needing to have to access to a Phenom SEM.

    After that, I will demonstrate how you can analyse these images using an external module and how you can generate a report using PPI.

    The Phenom PPI Simulator

    The Simulator can be created by calling the Phenom class in PPI and passing empty strings for the Phenom ID, username, and password. In code it looks like this:

    Acquiring images works in exactly the same way as I explained in my first blog on guidelines for script making.

    We create a class of ScanParams and fill it with the desired settings. In this case, we want to acquire an image with a resolution of 1024x1024, using the BSD detector, 16 frames to average, 8-bit image depth, and a scale of 1. The image is then obtained using phenom.SemAcquireImage(). The image is displayed in a matplotlib figure. The code for this is:

    The resulting image from the Simulator are repeating diagonal gradients, which is shown in Figure 1.

    Figure 1.Phenom Simulator image

    Analyse using an external module 

    In my previous blogs on script development and automated image analysis, I have shown how an image can be analysed and evaluated using external libraries. In this blog, we will use an external module and determine the peak to peak distance on a circular cross section of the image. To determine this distance we will import a great little module called detect_peaks.

    Using the detect_peaks module we can determine local peaks based on its characteristics. Importing an external module is as easy as downloading the .py file and putting it in the root directory of your script and then adding the following line to your import statements:

    We extract a circular path because it is a little more exciting than using just a straight line, where all the peaks would be equidistant, and the results would be rather dull. To create a circle with points spread by 1 degree, a radius of 300 pixels, and positioned in the middle of the acquired image:

    In this script we force the numbers to remain integers, otherwise, we cannot use them to extract a cross-section. This is done with astype(np.uint16), the numbers are now unsigned integers with a bit-range of 16 bits (i.e. from 0 to 65,535).

    Extracting the circle and peaks can now be easily done by:

    The mpd parameter in detect peaks is the minimum spread between the peaks and the mph is the minimum peak height.

    To plot the results, we create a new image. In the left-hand plot, we will show the acquired image with a circle indicating where we took the cross section and red crosses to show where the peaks were found. In the right-hand image, we will plot the value of the cross section with red crosses where the peaks were found. We will add titles and labels to the plot and save it to a jpeg file in order to be able to use it in the report later on.

    The resulting image will be displayed in the report we will generate in the next section.

    PPI reporting

    To powerfully report the results to a user of a script, PPI has its own PDF-reporting tool. It is based on libHaru. Creating a pdf is fairly easy, once you know which steps to take. The first step is to create a document in Python:

    In the document, we need to create a page. This is done by:

    All positioning of text and objects is done with reference to the bottom left corner of the page. The positions are given in points and the default resolution is 72 dpi, thus the default size for A4 is: 595x842 pixels. The size of the paper is saved into the height and width variables.

    In this document, I will show how you can make headings, write large sections of text, make tables, and include figures. We start by adding text. I added three different types of text, first a big and bold header, then a smaller italic header, and a section with a large string that runs over multiple lines.

    To create text we begin with page.BeginText(). After that, we set the font with page.SetFontAndSize(). Then we position the text to the top left of the document with a margin of 50 pixels (about 2 cm in the document) with page.MoveTextPos(). To insert text we add a line with page.ShowText(). To move to the next line we only have to set the relative movement over the page with page.MoveTextPos().

    The first time you call page.MoveTextPos() the starting point is the bottom left corner of the document, and the second time it is a relative change to the new position. Typically, if you have a long text it is a hassle to find where every line break should be. To automatically find where a line break should be a text box can be made. This text box automatically does the line breaks and alignments of the text for you.

    It can be called with page.TextRect(), and the following attributes are passed: a PPI rectangle giving the absolute position of the text box, the string with the text that should be printed in the report, and the alignment. You can also see that I have changed the font three times to be able to distinguish between headers and sub-headers and normal text.

    To make a table, normal text is used but is displayed in a structured manner. First a header is made using text spaced in a regular horizontal pattern. Below this header we want a single line. However, drawing is not allowed between page.BeginText() and page.EndText() parts, so we have to close the text part to draw and then reopen it again.

    To draw the line we move the position to the start location and use the page.LineTo() to define the line. The real drawing is done by page.Stroke(). After that we iterate over the items we want to put in the table and put them all in the right column, with the same spacing. The table ends with a double underlining. The code to do this is:

    To save the pdf pdf.SaveToFile() is used. To open the pdf the subprocess library can be used:

    The resulting PDF is:

    This blog concludes my series of blogs with guidelines for small script development, I hope you have enjoyed it. If you would like to learn more about PPI and automation you can download the PPI specification sheet below:

    Click here to learn more about SEM automation and the Phenom Programming Interface.

    Topics: Scanning Electron Microscope Software, Automated SEM Workflows,  Automation,  Automation, PPI

    About the author:

    Wouter Arts is Application Software Engineer at Thermo Fisher Scientific, the world leader in serving science. He is interested in finding new smart methods to convert images to physical properties using the Phenom desktop SEM. In addition, he develops scripts to help companies in using the Phenom desktop SEM for automated processes.

  • Keysight’s Truevolt Digital Multimeters (DMMs)

    Keysight’s Truevolt Digital Multimeters (DMMs) offer a full range of measurement capabilities and price points with higher levels of accuracy, speed, and resolution.

    Get more insight quickly
    Truevolt DMM's graphical capabilities such as trend and histogram charts offer more insights quickly. Both models also provide a data logging mode for easier trend analysis and a digitizing mode for capturing transients.

    Measure low-power devices
    The ability to measure very low current, 1 µA range with pA resolution, allows you to make measurements on very low power devices.

    Maintain calibrated measurements
    Auto calibration allows you to compensate for temperature drift so you can maintain measurement accuracy throughout your workday.

    Key specifications 34460A 34461A 34465A 34470A
    Digits of resolution
    Basic DCV accuracy 75 ppm 35 ppm 30 ppm 16 ppm
    Max reading rate 300 rdgs/s 1,000 rdgs/s 5,000 rdgs/s std 5,000 rdgs/s std
    50,000 rdgs/s opt 50,000 rdgs/s opt
    Memory 1,000 rdgs 10,000 rdgs 50,000 rdgs std 50,000 rdgs std
    2 million rdgs opt 2 million rdgs opt
    Measurements
    DCV 100 mV to 1,000 V 100 mV to 1,000 V 100 mV to 1,000 V 100 mV to 1,000 V
    ACV (RMS) 100 mV to 750 V 100 mV to 750 V 100 mV to 750 V 100 mV to 750 V
    DCI 100 μA to 3 A 100 μA to 10 A 1 μA to 10 A 1 μA to 10 A
    ACI 100 μA to 3 A 100 μA to 10 A 100 μA to 10 A 100 μA to 10 A
    2- and 4-wire resistance 100 Ω to 100 MΩ 100 Ω to 100 MΩ 100 Ω to 1,000 MΩ 100 Ω to 1,000 MΩ
    Continuity, diode Y, 5 V Y, 5 V Y, 5 V Y, 5 V
    Frequency, period 3 Hz to 300 kHz 3 Hz to 300 kHz 3 Hz to 300 kHz 3 Hz to 300 kHz
    Temperature RTD/PT100, thermistor RTD/PT100, thermistor RTD/PT100, thermistor, thermocouples RTD/PT100, thermistor, thermocouples
    Capacitance 1.0 nF to 100.0 µF 1.0 nF to 100.0 µF 1.0 nF to 100.0 μF 1.0 nF to 100.0 μF
    Dual line display Yes Yes Yes Yes
    Display Color, graphical Color, graphical Color, graphical Color, graphical
    Statistical graphics Histogram, bar chart Histogram, bar chart, trend chart Histogram, bar chart, trend chart Histogram, bar chart, trend chart
    Rear input terminals No Yes Yes Yes
    IO interface
    USB Yes Yes Yes Yes
    LAN/LXI Core Optional Yes Yes Yes
    GPIB Optional Optional Optional Optional
  • What is an FFT Spectrum Analyser?

    FFT Spectrum Analysers, such as the SRS SR760, SR770, SR780 and SR785, take a time varying input signal, like you would see on an oscilloscope trace, and compute its frequency spectrum. Fourier's theorem states that any waveform in the time domain can be represented by the weighted sum of sines and cosines.The FFT spectrum analyser samples the input signal, computes the magnitude of its sine and cosine components, and displays the spectrum of these measured frequency components.

    Click here to download the full Application Note.

     

    If you would like more information, to arrange a demonstration or receive a quotation please contact us via email or call us on 01582 764334.

  • Nano Mechanical Imaging

    The nano mechanical imaging (NMI) mode is an extension of the contact mode. The static force acting on the cantilever is used to produce a topography image of the sample. Simultaneously, at each pixel force curves are produced and used to extract quantitative material properties data such as adhesion, deformation, dissipation...

    Click here to read the complete article.

     

    To speak with a sales/applications engineer please call 01582 764334 or click here to email

    Lambda Photometrics is a leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Electronic/Scientific and Analytical Instrumentation, Laser and Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics and Microscopy.

  • New Baumer LX Cameras now with integrated JPEG compression

    We are pleased to announce that we are now delivering an on-board image compression video camera, which is able to transmit high-quality images and reduce the data output in real-time.

    Baumer is supplementing the hugely popular LX series with 2, 4 and 25 megapixel cameras with integrated JPEG image compression and frame rates of up to 140 fps. With the GigE cameras, your savings are continual: from bandwidth through CPU load to storage space – this simplifies the system structure design and reduces integration costs.

    Why not give us a call now on 01582 764334 if you would like a free trial of the camera or click here to email.

    Further information on our Machine Vision camera series click here.

    Lambda Photometrics is a leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Electronic/Scientific and Analytical Instrumentation, Laser and Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics and Microscopy.

  • LED Lighting Techniques

    The future belongs to LED technology. The long lifetime and high energy efficiency of these devices form the main reason for changing over to this technology for illumination requirements in Machine Vision.

    Depending on what the requirements are in terms of price, performance and flexibility, the user can find the best solution in the market using this state-of-the-art technology.

    The user has a number of options available to them for target illumination.

    Click here for a useful guide to help you choose the right lighting for your Machine Vision application.

    Alternatively why not contact our Machine Vision specialists on 01582 764334 or click here to email.

    Lambda Photometrics is a leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Electronic/Scientific and Analytical Instrumentation, Laser and Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics and Microscopy.

Items 1 to 10 of 179 total

Page:
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. ...
  7. 18