FTIR Spectrometer
Fibered Fourier-Transform Infrared Spectrometer (FTIR)

The FT-IR "Rocket" is a robust and small-footprint FTIR spectrometer. The FTIR Rocket can be used in a fiber connected version or a free space version. The device is very useful for IR measurements that needs fiber coupling or any other special arrangements like for IR light source characterization.
FT-IR "Rocket" offers high resolution and sensitivity thanks to its thermoelectrically cooled MCT (Mercury-Cadmium-Telluride) detector. Its permanentely aligned interferometer and its solid-state reference laser ensure the highest performance at every scan. The system has a good stability in both wavelength and intensity scales, which amkes it an ideal tool for highly reproducible chemiometrical analysis. The FT-MIR and FT-IR are also used by many of our customers for characterization of infrared lasers. Also Pulsed lasers with repetition rates above 10KHz can be measured.

Standard models of the FTIR-Rocket

FT-MIR Rocket 2-6μm

FT-IR Rocket 2-12μm

The FT Rocket infrared spectrometer is proposed in 2 standard versions: The FT-MIR 2 - 6μm, FT-MIR 1.5 - 8.5μm and the FT-IR 2 - 12μm. Both offer a resolution of 8cm-1, 4cm-1 or down to 2 cm-1. The main differences lie in the beamsplitter material (CaF2 or ZnSe) and the sensitivity of the detector: the narrower band 2-6μm detector has a much better sensitivity. On request we can fit the detector to your needs.

  • Compact (world Smallest FTIR)
  • High resolution 4cm-1 optionally up to 0.5 cm-1
  • Peltier cooled MCT detector
  • 3 spectral ranges: 5000-1700cm-1 (2-6μm), 6700-1200cm-1 (1.5 - 8.5μm) or 5000-830 cm-1 (2.5-12μm)
  • USB connectivity
  • Cost effective
How does it work?
Permanentely aligned interferometer

The heart of the FT-Rocket is dual corner-cube (retro-reflector) interferometer. The two corner-cubes are fixed to a common swinging arm, which rotates to create an optical path difference (with respect to the beam splitter) in the two arms of the interferometer.
This type of design is called a permanently aligned interferometer. This particular arrangement of the interfeormeter is known to be the most robust against vibrations and temperature drifts. It never has to be realigned.
The swinging arm of the interferometer rotates on wear-free flexure system, making this mechanical system extremely robust and durable.

Solid-state reference laser

For measuring the movement of the mirrors, a solid-state reference laser is coupled into the interferometer. Compared to classic HeNe lasers, the solid-state lasers that we use are more compact and have a much longer life-time. They have a very low temperature-induced wavelegnth drift and, when kept at constant temperature with a Peltier element, their wavelength can be stabilized to a few PPM, thus providing a very accurate and reproducible wavelength scale. This is crucial for ensuring a day-to-day and unit-to-unit consistency.

Model-dependent specifications

Models FT-MIR 2-6
FT-MIR 1.5-8.5
FT-IR 2-12
Beam-spliter material CaF2 CaF2 ZnSe
Spectral Range [cm-1] 5000 - 1700 6700 - 1200 5000 - 830
Spectral Range [μm] 2-6 1.5-8.5 2-12
Detector Type
D* [cm Hz1/2W-1]

MCT (2-TE cooled)


MCT (4-TE cooled)


MCT (4-TE cooled)


Signal-to-Noise (8cm-1 resolution and 1 min scan time) > 1:60'000 > 1:40'000 > 1:40'000
Recommended fiber
(usable wavelength range)

CIR (chalcogenide) fibers

CIR or PIR depending of the application PIR (polycrystalline) fibers
3-18 μm


Common specifications

Interferometer type

Permanentely aligned, double retro-reflector design

Resolution [cm-1 ]

4, 2, optionally 1 and 0.5

Wavenumber repetability

Scan frequency

1 spectrum/second
(in continuous aquisition mode)

optionally up to 8 spectra/second. Depends of resolution

Control laser

solid-state laser @850nm

A/D Converter 24 bit
Operating temperature 10°C-40°C
Free-space input Aperture Ø: 12.7mm
Acceptance full angle: 3.2°
Removable fiber-couplers Connector: SMA 905
Fiber core Ø: up to 1mm
NA=0.25 (lensed coupler) or NA=0.3 (reflective coupler)
Power requirement 12V / 8W
Communication Interface USB 2.0
Software Interface

Windows 7/10
API for controlling the instrument via our DLL

Dimensions 180mm x 160mm x 80mm
Weight 1800 g


Wavelength resolution

The resolution of Fourier-transform spectrometers is usually given in wavenumbers (ν), which are the inverse of wavelength (ν=1/λ). The conversion betwen wavenumber resolution and wavelength resolution is Δλ = λ2 · Δν and is shown in the graph below:

Features and benefits
Self-compensated Interferometer principle
  • Thanks to the self-compensated optical design, the interferometer remains stable with temperature variations and vibrations
  • Permanent alignment of the device
  • The solid-state internal reference reduces maintenance costs and avoid the need for high-voltage driving as for HeNe lasers
Simple operation
  • The spectrometer and software are designed for simple, plug-and-play operation
  • The small size and weight of the spectrometer allows easy hand carriage
  • Food, beverage & dairy
  • Pulsed laser measurement
  • Agriculture
  • Gas detection
  • Environmental monitoring
  • Security and defense
  • Cosmetics
  • Textile
  • Plastics
  • Process control (solar cells characterization, chemical monitoring, pharmaceutical manufacturing).
  • ... And many others
Free GUI basic software

The FTIR Rocket is delivered with a free Windows 7 & Windows 10 compatible graphical user interface (GUI) program.

The free basic software package allows the user to:

  • Configure hardware measurement parameters (amplifier gain, averaging, ...).
  • Display real-time spectral measurement results.
  • Set reference spectra (white, dark) and choose among raw spectra, transmission or reflection mode.
  • Usual features such as save, open, zoom, rescale...
  • Some specific features related to Fourier transform spectrometry: choose among spectrum or interferogram averaging, apodization, look and save the interferograms, etc.
Free API & Examples

The FTIR Rocket is also delivered with a free API that allows you to control the spectrometer with custom code via our DLLs. Examples are available for the following languages:

  • C++
  • C#
  • Labview
  • Matlab
Advanced data processing & analysis software
In collaboration with Labcognition GmbH in Germany we also offer additional Panorama software packages:
Math Add-on module

contains a set of standard manipulation operations used in spectroscopy, like normalization, derivative, baseline correction, peak picking and more. In addition some special operations are available, like multiplicative scatter correction, thickness correction or standard normal variate correction and others.

Quantity Add-on module
is an expert in multivariate data analysis with quantitative methods like PLS and MLR. A convenient and intuitive wizard guides you through all steps of calibration model development. Complex statistical methods become very easy to use even for non-experienced users.
Search Add-on module
is an ideal add-on to archive your spectroscopic data and related information. It includes spectrum and full text search functionality on spectral libraries of various different library formats or directly on data in the file system.
IRAnalyze software package

is a highly sophisticated IR spectrum interpretation tool. Based on an IR spectrum, it provides you with automatic results for IR bands to functional group correlations and their characteristic frequencies. Furthermore, it is a comprehensive electronic dictionary to browse frequiencies for correlated IR bands.


ArcLight MIR infrared light source

The ARCoptix ArcLight MIR is a versatile lamp optimized for mid-IR (1-25µm). The lamp features a high-end stabilized electronic power supply and a variable mechanical attenuator. It is supplied with a removable fiber coupler enabling free-space of fiber-coupled operations.

DOWNLOADpdf description of ArcLight sources

CIR optical fibers for 1-6 microns range

Chalcogenide-IR (CIR) fibers transmit IR-radiation in the spectral range of 1-6μm (10000 - 6500cm-1). They fill the gap between fused silica fibers (0.2-2.4μm) and polycrystalline infrared (PIR) fibers (4-18μm).

CIR fibers have an NA of 0.28 and are available with core diameters up to 500 µm. These fibers ideally match the range of our spectrometers using 2-6 µm MCT detectors.


PIR optical fibers for 4-18 µm range

Polycrystalline infrared (PIR) fibers transmit IR-radiation in the upper mid-IR range over 4-18μm (2500 - 550cm-1).

PIR fibers have an NA of 0.25 and are available with core diameters up to 900 µm.

DOWNLOADpdf description of NIR/CIR/PIR optical fibers
Bk7/CaF2 fiber coupler/collimator

Lens-based coupler provides a cost-effective solution for fiber coupling& collimation. Bk7 couplers are fine for the NIR range and up to 4 µm. CaF2 couplers are a good solution for the NIR and and MIR up to 8 microns. Standard fiber connectors are SMA-905, but FC/PC connectors or other types are available on request


Reflective fiber coupler/collimator

Reflective couplers/collimators are needed for the upper MIR range above 8 microns. These couplers use an off-axis parabolic mirror for optimal coupling performance throughout NIR & MIR. Standard fiber connectors are SMA-905, but FC/PC connectors or other types are available on request.

Non-exclusive Distributor list for spectrometers:
For OEM Business: contact Arcoptix directly. FTIR OEM Business
France, Germany
Italy, UK

Russia, Moscow FTIR Russia

South Korea
Switzerland and
Rest of the world
DOWNLOADpdf Description of FTIR-Rocket
DOWNLOADpdf Tutorial about Fourier Spectrometry
DOWNLOADpdf Solar cell characterization
DOWNLOADpdf Pulsed laser characterization
DOWNLOADpdf MIR Laser characterization