ROCKET: ARCoptix FTIR Spectrometer
Compact and versatile Infrared Fourier transform spectrometer

The "Rocket" is a robust and small-footprint FT-IR spectrometer. The FTIR Rocket can be used for free-space measurement, or alternatively for fibered applications thanks to a removable fiber adapter (included). The device is particularly useful for IR measurements that need fiber coupling or any other special arrangements such as IR light source characterization. The ARCoptix FTIR "Rocket" offers high resolution and sensitivity thanks to its 4 stage thermoelectrically cooled MCT (Mercury-Cadmium-Telluride) detector. Its permanently aligned interferometer and its solid-state reference laser ensure the highest performance at every scan. The system displays excellent stability in both wavelength and intensity scales, which makes it an ideal tool for highly reproducible chemometric analysis. The FTIR " Rocket" is also used by many of our customers for characterization of infrared lasers, including pulses sources with repetion rate >10 kHz.

FTIR Rocket with TE or LN2 cooling MCT detector

FTIR Rocket 2-12μm

FTIR Rocket 2-16μm with LN2 cooled MCT detector

The FTIR Rocket can accommodate various detectors, each displaying specific characteristics. Besides pryoelectric detectors (DLATGS), we offer a selection of thermoelectrically cooled (TEC) MCT detectors that enable achieving unprecented performances while keeping the instrument extremely compact. The FTIR Rocket can also be mounted with a liquid nitrogen (LN2) cooled MCT detector for demanding applications that require high signal-to-noise ratio (SNR) or specific setups with very low optical throughput. In its standard configuration, the FTIR Rocket can reach a resolution of 2cm-1 while our high resolution modules (available on request) can deliver up to 0.5cm-1.

Example of application using the ARCoptix FTIR spectrometer


  • Compact (world Smallest FTIR)
  • High resolution 4cm-1 optionally up to 0.5 cm-1
  • Peltier cooled MCT detector available
  • 4 spectral ranges: 5000-1660cm-1 (2-6μm), 6600-1200cm-1 (1.5 - 8.5μm), 5000-830 cm-1 (2-12μm) or 5000-650 cm-1 (2-16μm)
  • USB connectivity
  • Cost effective
How does it work?
Permanently 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

Product code FTIR-L1-060-4TE
Beam-spliter material CaF2 ZnSe
Spectral Range [cm-1] 5'000 - 1'660 6'600 - 1'200 5'000 - 830 5000 - 650
Spectral Range [μm] 2.0-6.0 1.5-8.5 2.0-12.0 2.0-16.0
Detector Type MCT (4-TE cooled) MCT (LN2 cooled) DLATGS
D* [cm Hz1/2W-1] >1x10E11 >8x10E9 >4x10E9 >5x10E10 >2.5x10E8
Signal-to-Noise (4cm-1 resolution, 1 min scan time) > 80'000:1 > 40'000:1 > 70'000:1 > 8'000:1
Recommended fiber) CIR (chalcogenide) fibers CIR or PIR depending of the application PIR (polycrystalline) fiber


Common specifications

Interferometer type

Permanently aligned, double retro-reflector design

Resolution [cm-1 ]

4, 2, optionally 1 and 0.5

Wavenumber repetability

Scan frequency

>4 Hz @ 4cm-1

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 7/10/11
API for controlling the instrument via our DLL

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


Frequently Asked Questions
What is the equivalent wavelength resolution of my FT-IR?

Owing to its operating principle, a FT-IR delivers a spectrum uniformly sampled over a given spectral range in wavenumbers (ν), with units of cm-1. The wavenumber is simply defined as the inverse of the wavelength (λ). The resolution of an FT-IR is constant in wavenumber (Δν), but varies with wavelength (Δλ) due to the inverse relationship between these two units. The conversion betwen wavenumber resolution and wavelength resolution is Δλ=λ2 · Δν and is shown in the graph below:

How to choose the best detector for my application ?

The choice of a detector is a most sensitive one as it contributes to a large extent to the overall quality of your measurement. ARCoptix offers several types and models of detectors, namely extended InGaAs detectors (2 stage thermo-electric cooling), HgCdTe (MCT) detectors with either thermoelectric cooling (4 stages) or liquid nitrogen cooling as well as pyroelectric (DLATGS) detectors. Selection of a given detector is application driven, and depends on the spectral signatures that you are willing to analyze. In order to deliver a faire comparison between various types of photodetectors (or thermal detectors), the most widespread metric is the specific detectivity (labelled D*), which is given in the figure below for all of our available detectors.

ARCoptix Digital Acquisition Acquisition system: AoDAQ

The AoDAQ is a multi-threading, cross-platform and versatile software that simultaneously takes care of:

  • (1) Handling communication with the FT-IR via USB
  • (2) Processing raw signals to deliver the spectrum
  • (3) Running a TCP ethernet server

The AoDAQ can be installed on all sorts of computers, from desktop machines to embedded, low-power single board computers. Thanks to the hosting of a TCP server, the instrument data and parameters can be accessed locally and/or remotely. All communication with the instrument eventually reduces to a set of TCP/IP commands that allow to quickly acquire data, adjust parameters, monitor the instrument status etc. using the programming environment of your choice.

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

Optical fibers

ARCoptix offers two types of optical fibers for the mid-infrared:

  • Chalcogenide-IR (CIR) fibers transmit IR-radiation in the spectral range of 1-6μm (10000 - 6500cm-1). CIR fibers have an NA of 0.28 and are available with core diameters of 500 µm. These fibers ideally match the range of our spectrometers using 2-6 µm MCT detectors.
  • polycrystalline infrared (PIR) fibers transmit IR-radiation in the spectral range of 4-18μm. PIR fibers have an NA of 0.25 and are available with core diameters of 900 µm. These fibers ideally match the range of our spectrometers using 2-12 µm MCT detectors.
  • DOWNLOADdescription of NIR/CIR/PIR optical fibers

    Fibered reflection probes

    ARCoptix offers two types of optical fiber reflection probes for the mid-infrared:

  • Chalcogenide-IR (CIR) reflection probes transmit IR-radiation in the spectral range of 1-6μm (10000 - 6500cm-1). The bundle consists in 6, 600µm core CIR fibers and a single 600µm core CIR fiber for readout that are held in a ¼" ferrule. These probes ideally match the range of our spectrometers using 2-6 µm MCT detectors.
  • polycrystalline infrared (PIR) reflection probes transmit IR-radiation in the spectral range of 4-18μm. The bundle consists in 6, 600µm core CIR fibers and a single 600µm core CIR fiber for readout that are held in a ¼" ferrule. These fibers ideally match the range of our spectrometers using 2-12 µm MCT detectors.
  • DOWNLOADpdf description of optical fibered probess

    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

    South Korea
    Switzerland and
    Rest of the world