NLIR
Nonlinear Infrared Sensors
MIR UP-convertion Spectrometers
NLIR - MIDWAVE Spectrometer
The NLIR MIDWAVE Spectrometers cover a broad part of the MIR spectrum where the spectral fingerprints of many C-H bonds of gases are located together with those of a number of other common gases. Many plastics (independent of color) also absorb in this MIR region, which makes indentification easily accessible.
Spectrometer Details
Developers in both industry and research use mid-infrared (MIR) spectrometers for non-invasive characterization of gases, liquids, and solids as well as characterization of light sources. NLIR’s MIDWAVE Spectrometer is a fast, portable, and versatile tool for measuring mid-infrared light in the 2.0 – 5.0 μm range. Designed for applications requiring high-speed and accurate spectral measurements, it captures full spectra in milliseconds, making it ideal for both in and out of the lab.
NLIR’s MIDWAVE Spectrometer has high sensitivity of -80 dBm/nm or better, and the full-spectrum readout rate of 400 Hz! The spectrometer enables the characterization of light sources and measuring spectral content from chemical processes with a time resolution of 10 µs.
Powered by NLIzeR Software
MIDWAVE Spectrometer comes with an NLIzeR Software for easy spectral analysis. With NLIzeR, you get:
Adjustable exposure time, averaging, gain, and offset, Live data stream, external trigger mode, background capture,
transmission view, data saving, and many more features
API interfaces for MATLAB, Python, and C (via DLLs), enabling seamless integration into custom workflows or automated processes.
Key applications:
- Black plastic sorting
- Gas concentration measurements
- Polymer identification
- Petrochemical analysis
- Broadband IR coating quality control
- MIR super-continuum light measurements
Key features
- Up to 130 kHz full-spectrum readout rate
- -80 dBm/nm sensitivity
- 2.0 – 5.0 μm bandwidth
- Fiber-coupled input
- Plug-n-play
NLIR - CUSTOM Spectrometer
Developers in both industry and research use mid-infrared (MIR) spectrometers for non-invasive characterization of gases, liquids, and solids as well as characterization of light sources. NLIR specializes in manufacturing 2.0 – 5.0 µm spectrometers based on a novel measurement scheme that upconverts the MIR light to near-visible light. Silicon-based near-visible light detectors are far superior to MIR light detectors in terms of detectivity, speed, and noise. The NLIR upconversion technology, therefore, brings these attractive features and the advantages that follow, to the MIR regime.
NLIR can customize their standard spectrometer to optimize performance in the wavelength range that suits your application the best. Generally, a narrower wavelength range gives higher response and possibly better resolution.
NLIR - BUNDLE Spektrometer
Developers in both industry and research use mid-infrared (MIR) spectrometers for non-invasive characterization of gases, liquids, and solids as well as characterization of light sources. NLIR is glad to present unprecedented upconversion technology, which can power VIS/NIR spectrometeres with MIR spectra readout in real time.
By combining NLIR’s upconversion solution — the SPEKTRUM Wavelength Converter — with high-end, commercially available VIS/NIR spectrometers in a BUNDLE Spectrometer configuration, powerful mid-infrared analysis becomes both accessible and efficient. The Wavelength Converter shifts the MIR light to the VIS/NIR range, allowing standard silicon-based spectrometers to detect it. The two devices are simply connected via an optical fiber — no additional components or setup required.
NLIR- SPEKTRUM Wavelength Conversion Modul
The core of NLIR’s technology is the wavelength conversion module, which upconverts mid-infrared wavelengths to the near-visible range, enabling the use of Si and GaAs detectors. The conversion is driven by a high-power, continuous-wave 1064 nm laser inside a lithium niobate crystal. Everything is integrated and no alignment is necessary.
The SPEKTRUM Wavelength Converter offers broad-range wavelength conversion from 1.9 – 5.3 µm in the mid-infrared to 682 – 886 nm in the visible/near-infrared. All wavelengths within this range are converted simultaneously, without time lag or any scanning elements. The output can be analyzed using a conventional fiber-coupled grating spectrometer or detector with silicon-based sensors.
Only the vertical polarization component is upconverted, which may reduce the amount of signal converted but correspondingly it also reduces the converted noise to half. After conversion, efficient spectral filtering below 695 nm and above 886 nm cuts away residual noise.
The translation to near-visible wavelengths gives further advantages than lower noise-equivalent power. Higher detection speed than conventional MIR detectors is readily available by just plugging the output fiber into a GHz GaAs detector; 10 GHz or even 25 GHz detectors are available off-the-shelf. Even further, standard near-visible light detectors often come pre-amplified with a response of up to GV/W, which eases the measurement of the electrical output.
The NLIR wavelength conversion module is an extremely versatile tool for any mid-infrared laboratory. Flexibility in mid-infrared measurement equipment is often desirable but expensive to buy. With the wavelength conversion module many different affordable detectors and spectrometers become available, and in many cases, it even gives better performance than using expensive conventional mid-infrared detectors.
WAVELENGTH CONVERSION TECHNOLOGY EXPLAINED
The size of the bandwidth in SPEKTRUM Wavelength Converter has a significant impact on the efficiency of photon conversion. For the smallest bandwidths of around 50 nm, the conversion efficiency can reach up to 0.1, enabling extremely sensitive measurements. Meanwhile, wider simultaneous conversion such as 3.3 µm to 5.3 µm results in a conversion efficiency of approximately 0.005, and even wider conversion from 1.9 µm to 5.3 µm has a conversion efficiency of 0.0002.
The ideal combination of bandwidth and conversion efficiency varies depending on many factors, but even the lower conversion efficiencies offer new possibilities for measuring, particularly in spectroscopic applications. Higher conversion efficiencies, coupled with the right visible-light detector, can provide some of the fastest and most sensitive infrared measurement methods available.
Compared to traditional mid-infrared spectrum analyzers, even affordable visible/near-infrared spectrometers provide significantly higher speed and sensitivity. The SPEKTRUM Wavelength Converter leverages these advantages, bringing visible-light spectrometer performance to mid-infrared measurements. Additionally, fast and sensitive photodetectors can be easily connected for real-time mid-infrared signal analysis in the time domain.
NLIR - TUNE Wavelength Converter
Details
The core of NLIR’s technology is the wavelength conversion module, which upconverts mid-infrared wavelengths to the near-visible range, enabling the use of Si and GaAs detectors. The conversion is driven by a high-power, continuous-wave 1064 nm laser inside a lithium niobate crystal. Everything is integrated and no alignment is necessary.
The TUNE Wavelength Converter is designed to maximize conversion efficiency within a narrow bandwidth, ensuring the highest possible sensitivity for mid-infrared light measurements.
It operates in the 2.3 – 4.2 µm range, allowing users to precisely tune the conversion to the desired the wavelength. The converted light is shifted to the 727 – 849 nm range, making it compatible with any fiber-coupled detector operating at these near-infrared wavelengths.
Applications
TUNE Wavelength Converter is best suited for detecting narrowband signals that are either weak or vary rapidly over time. It is particularly effective for measuring weak pulsed signals using time-gated PMT or SPAD detectors, while rapidly fluctuating signals can be captured with APDs or high-speed PIN photodiodes.
The conversion efficiency¹ is typically 3 %.
¹ Conversion efficiency measured with a 100 µm core size 0.2 NA InF₃ input fiber. With optional free-space input, the conversion efficiency can be 10 % with optimally aligned input.
NLIR Light Source FIBER
Thermal light directly in a fiber
FIBER LIGHT SOURCE
- Optical Bandwidth 1.2 - 8.0 µm
- Source 1375 °C Silicon Carbide
- Output Power * >5 mW
- Optical Output SMA-905 Fiber Connector
Product Details
High-temperature mid-infrared (MIR) light sources are relatively cheap and require only simple electronics; they emit light of high power and are stable and robust. However, due to the nature of the warm emitter, the light is incoherent and emitted in all directions, which makes it difficult to guide and focus the light onto a sample with high intensity.
NLIR’s FIBER Light Source makes it easy to bring MIR light to a sample either by positioning the fiber tip close to the sample or by using commercially available fiber-probes.
The light source is plug-and-play, turns on in a few seconds, and is actively temperature stabilized, and no parts are too warm to be touched.
INTERFACES
NLIR Interface I TOUCH
The NLIR TOUCH Interface is a measurement instrument that helps easily bring light to and from a sample when performing reflection measurements. It has a built-in wide-band light source, and after being reflected on the sample, the light is coupled into a connected fiber to conveniently bring it anywhere. The TOUCH Interface is designed to work with differently shaped sample surfaces while at the same time minimize background signal.
NLIR - Interface REFLECTION
NLIR’s REFLECTION Interface is an optical system designed to reflect and direct infrared (1.0 – 10.0 µm) light efficiently. It is used in various applications where reflection-based optical pathways are needed.
It consists of two independent products AURALIS Light Source and SAMPLER Accessory. Designed to be fiber-coupled with MIDWAVE Spectrometer, this interface allows you to perform reflection measurements at a 15° angle, 150 mm distance. Mounting NLIR’s REFLECTION Interface on a stand in your production line allows you to perform reflection measurements at scale, in real time.