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OMA V |
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From the NIR Leader
Researchers can now probe deeper into their sample materials using PI's OMA V detectors to discover hords of new data. Investigations in this spectral region are becoming increasingly vital in many research applications, including polymer and fuel research. Sensitivity in the 2.2 µm region is especially useful for analyzing moisture content, as well.
The InGaAs utilized in our newest OMA V systems has much less intrinsic dark noise than earlier generations of extended InGaAs. In many cases, PI OMA V 2.2 µm detectors provide ten times the sensitivity of previous extended-InGaAs detectors.
NIR Raman with Diode Laser Excitation
Raman spectrum of CCI4 acquired using OMA V (2.2-µm InGaAs)
785-nm excitation, 200-µm collection fiber
World's Finest NIR spectroscopy Detectors To-Date
PI's OMA V 16-bit InGaAs detection systems offer ulta-sensitive detectors perfect for collecting world-class spectral data. Offering the lowest readout noise and the highest dynamic range of any instrument of its kind, the OMA V 16-bit InGaAs is considered the best detection systems for NIR absorbance/reflectance, NIR Raman, laser photometry, or NIR fluorescence.
Best Overall Response
Our latest OMA V detectors utilize linear photodiode arrays (PDAs) designed to offer excellent near-infrared sensitivity from 1.0 µm to 2.2 µm. Detectors tailored to provide high sensitivity from 0.8 µm to 1.7 µm are also available.
Superior Resolution
Select a 1024-pixel format to achieve exceptional resolution with good spectral data rates or a 512-pixel format for excellent resolution with exceptional spectral data rates .
Resolution Comparison (OMA V 1.7-µm InGaAs Detectors)
(Section of Neon Spectrum)
In addition to the overall number of pixels in a detector, the size of each individual pixel is a determining factor in resolution. Our 512-pixel and 1024-pixel linear arrays have the same active area. However, because the 1024 format fits twice as many pixels in the same length, the smaller width of the pixels in the detector delivers superior resolution.
Outstanding Spectral Rates
The OMA V platform lets operators take 20 µsec snapshots for protocols requiring sustained high-speed data acquisition, supporting spectral data rates up to 1800 spectra/second (512 pixels) or 900 spectra/second (1024 pixels). Contact us to discuss customized models for even faster rates.
Excellent Cooling
Cryogenic cooling to -100C minimizes thermally-generated dark current in order to “stare longer” and preserves superb low-noise performance across the broadest possible spectral range.
PI's OMA V detection systems have been engineered to provide outstanding thermostating precision across a wide temperature range, enabling operators to tune their detector's wavelength sensitivity.
USB 2.0 for Fast and Easy Networking
For simple connection to desktop, laptop, and notebook PCs, all OMA V systems are offered with a USB 2.0 interface.
Outstanding Solutions
OMA V detectors are configured to mount directly to PI spectrographs. Adapters are also available for other popular spectrometers. Of course, high-performance spectroscopy solutions are easily controlled and monitored with our WinSpec software package (compatible with Microsoft® Visual Basic®), the SITK™ plug-in for National Instruments' LabVIEW™, and the Roper Scientific® PVCAM® application programming interface.
Equipment, Expertise, Experience: Everything for NIR spectroscopy Needs
NIR spectroscopy Fundamentals
Why Work in the NIR?
Working in the NIR gives spectroscopists several advantages, such as unwanted fluorescence background, which helps improve signal-to-noise ratio and is generally lower in the near-infrared region of the spectrum. NIR detectors can also probe deeper into sample surfaces.
About NIR Detectors
Because the silicon used in scientific-grade CCDs for UV-VIS spectroscopy cannot provide photosensitivity beyond 1.1 µm, a different material is required for working in the NIR.
Indium Gallium Arsenide (InGaAs) is a III-V compound semiconductor which affords excellent photosensitivity in the NIR. Changing this material's doping concentration alters its sensitivity. Unlike silicon, InGaAs is utilized in a PDA - a linear array of discrete photodiodes on an integrated circuit chip - rather than in a CCD.
Background Reduction
There are two types of backgrounds which must be suppressed when using an NIR spectroscopy detector. The first is the thermally generated dark charge associated with the operation of the detector. The second is the ambient background.
By cooling the detector, dark current can typically be reduced to the point where it is not a limiting factor. Ambient background can be minimized by cooling the detection system's optical path.
Temperature & Ambient Background Radiation
(Dark Counts vs. Temperature
100-sec integration, low-noise mode)
Temperature Tuning
Since the quantum efficiency of InGaAs shifts with deeper cooling, the temperature of the detector can actually function as a tunable filter, effectively narrowing the device's sensitivity to the wavelength of interest.
Cryogenically cooled OMA V models provide thermostating precision of ±0.05ºC across their entire temperature range (i.e., between -50 and -100ºC, or between -70 and -120ºC), allowing you to fine-tune detector sensitivity while screening out unwanted background.
Temperature & Quantum Efficiency
(Relative Response of InGaAs)
Cold Shield
PI has designed a cold "shield" for installation in a camera's vacuum chamber to assist in reducing the effects of thermal background radiation. This "cold shield" is installed onto every OMA V camera shipped from the factory.
Other Considerations
Light sources (such as YAG lasers and Xe light), spectrographs, optics, software, and accessories such as sample chambers, play a significant role in spectroscopy experiments. Our application engineers are happy to discuss all of your NIR spectroscopy requirements.