Laser Applications | Spectrum
The unique characteristic of laser light is that it is highly coherent. High spatial coherence means that laser beams can be focused into small spots and collimated beams can travel vast distances with minimal dispersion. Lasers can also produce light that is high in temporal coherence. This means the emitted light has a narrow spectrum or is of a single color. Temporal coherence also makes it possible to produce pulses that are narrow, with the fastest lasers being able to produce pulses that go down into the femtosecond range. The unique quality of laser light has resulted in lasers now being used in an increasing number of applications. This includes fields as diverse as science, medicine, communications, chemistry, printing, data storage, imaging, welding, robotics, surveying, mapping, guidance and cutting.
To convert laser light into an electrical signal a sensor or detector is typically needed. Depending on the application, these sensors can be photo-diodes, photo-multipliers, detectors using scintillation techniques and CCD's, or some other other photo-voltaic device. For situations that require fast and accurate capture of the electrical signals Spectrum has a range of digitizers that can be employed. For example, 8 bit digitizers are available that offer up to 5 GS/s sampling rates and 1.5 GHz bandwidth. These products are ideal for making timing measurements, or capturing and analyzing pulses, that go down into the nano-second and sub-nanosecond region. When large dynamic range and maximum sensitivity is required high-resolution 14 and 16 bit digitizers are available for the capture and analysis of signals that go as high as 250 MHz in frequency. These high-resolution products deliver outstanding signal-to-noise ratio's (up to 72 dB) and spurious free dynamic range (of up to 90 dB) so that small signal variations can be detected and analyzed.
The digitizers are also equipped with ultra-fast trigger circuits, complete with trigger time stamping, so that the dead-time between acquisitions can be extremely small (down to as little as 16 ns). Together with large on-board memories (up to 4 Gsamples/card) and advanced streaming and readout modes this makes the digitizers ideal for applications where long and complex signals need to be captured and analyzed. Data can be stored in the on-board memory or streamed in FIFO mode over the fast PCIe bus of the digitizer to a PC. By streaming data to a RAID based storage array it's even possible to seamlessly store hours of information. To help with data analysis and data reduction Spectrum's M4i series of digitizers also feature on-board FPGA based processing functions that can be perform on-the-fly Averaging and Peak detection routines.
Each digitizer card can have from one to four channels and up to eight cards can be linked together with Spectrum's StarHub system to create instruments with up to 32 fully synchronous channels, making them perfect for applications where multiple sensors and large sensor arrays are deployed.
Typical laser applications include laser ranging, 3D modeling, LIDAR and LADAR, LDA/PDA, time interval measurements for printers and optical components, data storage, laser absorption spectroscopy, medical imaging (including optical coherence tomography), mass spectroscopy, interferometry, guidance systems, fiber optic communications, optical backscatter reflectometry and distributed temperature and strain measurement.
Spectrum Product Features
- 5 GS/s Sampling Rates with high Bandwidth
- 14 and 16 Bit Resolution
- Fast Trigger and Read-Out rates
- On-board Block Statistics (Peak Detect)
- On-Board Block Average
Matching Card Families
- M4i.22xx: 8 bit 5 GS/s to 1.25 GS/s digitizer
- M3i.21xx: 8 bit 1 GS/s to 250 MS/s digitizer
- M2i.20xx: 8 bit 200 MS/s to 50 MS/s digitizer
- M4i.44xx: 14/16 bit 500 MS/s to 130 MS/s digitizer
- M3i.48xx: 16 bit 180 MS/s to 65 MS/s digitizer
Modular digitizers allow accurate, high resolution data acquisition that can be quickly transferred to a host computer. Signal processing functions, applied in the digitizer or in the host computer, permit the enhancement of the acquired data or the extraction of extremely useful information from a simple measurement.
The VivoSight® OCT scanner uses the technique of swept-source Optical Coherence Tomography (SS-OCT) for cross-sectional imaging of skin. This is a significant new tool to assist in diagnosis and treatment of skin cancers and other skin conditions.