BragGrate™ Deflector

Transmitting Volume Bragg Grating for angular selection and magnification

BragGrate™ Deflector is a transmitting volume Bragg grating recorded in a bulk of photosensitive silicate glass. The Deflector acts as a very narrow band mode selector in angular and spectral spaces and, therefore, enables spectrally selective beam steering and angular magnification. The spectral filtering is as narrow as 0.1 nm and can easily achieve deflection angles of up to 45 degrees. The grating is embedded inside the glass material and is stable to light powers exceeding 1 kW, temperatures >400°C, and is fully environmentally stable.

Schematics of a spectral and angular filters with BragGrate™ Deflector. Narrow spectral or angle selection is rejected from the incident beam.

Specifications

• Diffraction Efficiency (DE): 5-99%
• Spectral Bandwidth: 0.5 nm to 100 nm
• Operating Range λ: 400-2700 nm
• Grating Thickness: 0.50-10 mm
• Apertures: up to 50×50 mm²
• Angular Selectivity: 0.1-100 mrad
• Total Deflection Angles: <120 deg

Standard Parameters

• Center Wavelength: 532, 1064, 1550 nm
• Spectral Bandwidth (FWHM): 10 nm
• Diffraction Efficiency: > 97%
• Lateral Dimensions: 12.5×12.5, 25×25, 35×35 mm²

Angular magnification with BragGrate™ Deflector in electro-optic switches (Courtesy of Fujitsu Ltd. IEEE Phot. Tech. Lett., vol. 19, p. 701 (2007))

Advantages & Features

• High powered operations over 1 kW
• High energy operations up to 5 J/cm²
• No degradation over lifetime
• Superior environmental stability
  
• Very high angular selectively

• No polarization dependence at small incident angles
• Near-diffraction-limited beam quality
• Possible multiplexing of different angular selectors in one volume
• Low wavefront aberrations

Applications

• 3D beam steering
• Angular magnification in fast switches
• Transmitting spectral and angular selector
• Beam combining
• Beam shaping and filtering