Transmitting or reflecting volume Bragg gratings for spectral beam combining

BragGrate™ Combiner is a transmitting or reflecting volume Bragg grating (or set of gratings) enabling Spectral Beam Combining (SBC). It combines laser radiation from numerous sources into a single, nearly diffraction-limited beam with increased energy brightness. SBC by means of our BragGrate Combiners is a simple and robust technique for combining high-power laser radiation with a record spectral brightness. Excellent mechanical properties and a refractive index that is independent of temperature enables the Combiners to withstand high-power laser radiation, thus making them the ideal elements for high-powered SBC.


  • Diffraction Efficiency (DE): 90-99%
  • Spectral Bandwidth: 50 pm to 20 nm
  • Operating Range λ: 400-2700 nm
  • Grating Thickness: 0.50-10 mm
  • Apertures: up to 50×50 mm2
  • Angular Selectivity: 0.5-10 mrad
  • Deflection Angles: 5-45 deg

Standard Parameters

  • Center Wavelength: 930-980, 1030-1100 nm
  • Spectral Bandwidth (FWHM): 0.2-0.5 nm
  • Diffraction Efficiency 95-99%
  • Lateral Dimensions: 15×15, 20×20 mm2

Advantages & Features

  • High power operations up to 10 kW
  • High energy operations up to 5 J/cm2
  • Unrestricted lifetime; no degradation of parameters has been detected for 10 years
  • Very high angular selectivity (TBG)
  • Very high spectral selectivity (RBG)
  • Superior environmental stability
  • No polarization dependence at small incident angles
  • Nearly diffraction-limited beam quality


High power spectral beam combining Latest achievements: 5-beam combining with total output power of 780 W, combining efficiency of > 90%, channel spacing 0.25 nm.


Spectral beam combining scheme with 4 BragGrate™ Combiners


Spectrum of spectrally-combined output beam with a total power of 780 W and channel spacing of 0.5 nm