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BBO, Z-Cut, 4x4x20mm, AR coating and Cr+Au electroded for EO applications

Code: 2041-002



Materials Betta BBO crystals Size (4±0.1mm)x(4±0.1mm)x(20+0.5/-0.1mm)
Cut Angle Z-Cut Clear Aperture central 90% or the diameter
Scattering of Crystals

No visible scattering paths or centers

when inspected by a 50mW green Laser

Flatness less than λ/8 @ 633nm
Transmitting Wavefront Distortion less than λ/8 @ 633nm Chamfer ≤0.2mmx45°
Chip ≤0.1mm Surface Quality better than 10/5 S/D (MIL-PRF-13830B)
Parallelism ≤20 arc seconds Perpendicularity ≤5 arc minutes
Angle Tolerance ≤0.25° Coating AR/AR@1064nm on both end surfaces
Cr-Au electrode on two side surfaces
Quarter-wave voltage@1064nm ~4.3kV Optical Transmission >98%
Typical capacitance 3pf Damage Threshold >500MW/cm^2 @1064nm, 10nS
Quality Warranty Period one year under proper use


  • High repetition rate
  • High peak power damage resistance
  • Low absorption
  • UV transmission
  • Low acoustic noise

BBO is one of the electro-optic material choices for high average power pockels cell applications. BBO has significant advantages over other materials in terms of laser power handling abilities, temperature stability, and substantial freedom from piezoelectric ringing. Because it relies on the electro optic effect, switching time - aided by the low capacitance of the pockels cell is very fast. The wide transparency range of BBO allows it to be used in diverse applications. Double crystal design is employed in order to reduce required voltages and allowing operation in half-wave mode with fast switching times. Hangzhou Shalom EO offers the BBO crystals used in the pockels cells with AR coating and Cr-Au electrodes, stocked crystals of standard specifications is provided, and the customized special crystals is available upon customer’s request.


  1. High repetition rate DPSS Q-switches
  2. High repetition rate regenerative amplifier control
  3. Cavity dumping
  4. Beam chopper

Application Notes:

Calculation of Quarter-wave Voltage

The voltage required to produce a retardance of π radians is called the halfwave voltage or simply Vπ. For an optical input linearly polarized 45o applying a halfwave voltage rotates the polarization by 90o. When the output wave is passed through a linear the resultant can be rapidly modulated from maximum intensity to minimum intensity by rapidly changing the voltage applied to the crystal from 0 volts to Vπ.

The halfwave voltage of BBO is dependent on the optical wavelength and is given by:

Where   λ=optical wavelength 
         d=electrode spacing 
         L=optical path length 
         r22=electro-optic coefficients 
no=ordinary indices of refraction


EO Q-Switch 1/4Wave Voltage Vs wavelength (3x3x20mm) 
1/4 Wave Voltage @1030nm : Vπ/2 =3388V

Beta BBO
4 weeks