Federal State Budgetary Institution of Science
"Scientific and Technological Centre of Unique Instrumentation"
of the Russian Academy of Sciences

Acousto-optic spectrometer for Infra-red (IR-AOS)

IR-AOS detects spectral characteristics of optical radiation of infra-red range. It can be used in measurements based on emission spectroscopy and absorption differential spectroscopy.


  • Out-of-door measurements: atmosphere gas analysis, express-analysis.
  • Industrial applications: quality testing, plastics identification.
  • Laboratory investigations: scientific researches, spectral analysis, spectral identification algorithms development, spectral data base accumulation.

Characteristic features:

  • Fast random spectral access.
  • Insensitivity to shocks, impacts, vibration.
  • Applicability to out-of-door environment.
  • Small overall dimensions, compact design of optical head.
  • High throughput combined with rather high spectral resolution.
  • Operation mode variability. Programmability. Background operation.

Technical characteristics:

  • Spectral range 2.1 – 4.4 mcm
  • Bandwidth 10 nm at 3.39 mcm (9 cm-1)
  • Aperture 2°* 2° 12* 12 mm
  • Sizes:control unit  24.5*12*21.5 cm3 4 kg
  • optical head 36*14*6 cm3 2 kg
  • Temperature interval 3¸35°C

Brief description:

The basic part of spectrometer is a monochromator comprising a pair of acousto-optic tunable filters. Each filter contains a TeO2 crystal cell, in which a bulk periodic refractive structure is generated by ultrasound wave. The structure serves as a phase diffracting grating for incident radiation. The grating alters the polarization and the wavefront of a certain spectral component of incident radiation and a system of diaphragms separates it. As the wavelength of selected spectral component is defined by the grating period, the acousto-optic filter is tuned by varying the frequency of the signal supplied to the acoustic source. Due to polarization principle of separation used by acousto-optic filters, only one polarization component of incident radiation (horizontal) is detected.

Acousto-optic spectrometer consists of small-size optic head and control unit based on Compact PC system box. The spectrometer is programmable and allow short-time random spectral access. Spectrometer can be controlled from any IBM-compatible computer via serial port. Device can be used as a separate computer-controlled instrument.