About Us

BBT-Materials Processing Ltd. is a small private technological company dedicated to development and production of high performance mid-IR and TIR polarization birefringent optics  (up to 17 microns) and Acousto-Optical components for a wide range of applications.

The company is a worldwide leader in crystal growth and processing of high purity Calomel (mercurous chloride) crystals applied in mid-IR optics. The unique properties of this optical material make it a great candidate for manufacturing of different types of components such as polarizers, depolarizers, savart plates, AO cells, birefringent components for interferometry and FTIR spectroscopy, custom substrates, and others applied from VIS to mid-IR spectral region.

Besides IR optics, BBT is also active in the field of Acousto-Optical devices and hyperspectral imaging systems. Thanks to Calomel’s exceptionally high figure of merit M2, the material is suitable for manufacturing of AO units, targeting particularly the MWIR and LWIR region, where no other competitive material is available.

Mercurous chloride monocrystals seems to be also a very promising material for THz optics (retardation plates, polarizers, etc.) as the material is also transparent in THz spectral region.

As a long-term (since 1969) participant in several different R&D space activities, BBT represents a skilled and experienced partner in the field of primary and applied research in space and microgravity conditions using the unique optical material of Calomel.


TITUS space facility with German astronauts Hans-Dieter Schlegel and Reinhold Ewald

CSK-1C furnace with astronauts Pedro Duque (Spain) and Ulf Merbold (Germany)

CSK-1C space furnace – German astronaut Klaus-Pieter Flade (Project MIR’92, Photo DLR, Germany)

  • 2020: Investigation of components for birefringent interferometry and FTIR spectroscopy
  • 2019: Commercial versions of Glan-Foucault and Wollaston polarizers for mid-IR
  • 2016: Research project dedicated to study of calomel based AOTF (ESA)
  • 2014: First large Calomel crystal grown (35mm diameter)
  • 2014: First Calomel infrared polarizer tested (MIR and LWIR region)
  • 2012: Calomel qualified for use in space environment (ESA)
  • 2008: Beginning of continuous cooperation with ESA in the field of infrared optics and acousto-optics
  • 2008: New crystal growth and processing facility installed / Entry of new shareholder (Fastlite-FR)
  • 2001-2005: Advanced TITUS – multi-purpose platform – developed for ISS.
  • 2001Termination of MIR (CSK furnace 17 years and TITUS crystallizer 6 years non-stop on board MIR)
  • 1995-2001: Material space experiments on board MIR using TITUS crystallizer
  • 1995: BBT-Materials Processing Ltd. company was established
  • 1992-1995: Material space experiments on board MIR using CSK-1C furnace
  • 1991: “Čestmír Barta, BBT – Materials Processing, Crystal Science and Technology institute” established by Čestmír Barta jr.
  • 1976-1988: Material space experiments on board Salyut 6 – Sojuz and MIR (within Inst. of Physics, CAS)
  • 1969 – Discovery of Calomel as an optical material by Čestmír Barta sen.

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  • To offer high quality and high performance infrared polarization components and AO components for spectroscopy and optical systems, research and scientific teams, chemistry and industry manufacturers and others worldwide.
  • To continuously develop and offer new products to enable novel solutions and applications for customers


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  • To become a stable market supplier of unique optical components with high performance properties in MWIR and LWIR optics.
  • To apply innovative calomel products in space and commercial applications.
  • To build a first LWIR hyperspectral imager based on Calomel AOTF for the exploration of Earth (and other space objects) from space.



Čestmír Barta


barta(at) bartabbt(at)

Founder and CEO of the BBT – Materials Processing. Project leader of number of scientific and technological projects in the field of crystal growth, material sciences in space and development of high-tech space related facilities (for ESA, DLR MUSC, CNES, Energija – for MIR and ISS).

Lukáš Chroust

Project manager – IR optics


Senior research fellow and experienced material engineer. Several years of experience in the R&D projects, IR optics production and materials processing technologies. Responsible for marketing and business development activities.