BBO (Beta-Barium Borate) is a nonlinear crystal that is widely used in laser technology for frequency conversion. BBO has a high nonlinear coefficient, a broad transparency range, and a high damage threshold, making it an efficient material for second harmonic generation (SHG), sum frequency generation (SFG), and difference frequency generation (DFG).
In SHG, the frequency of a laser beam is doubled by passing it through a BBO crystal. This process is used to generate light in the ultraviolet range, which is useful in applications such as fluorescence microscopy and laser spectroscopy.
SFG involves combining two laser beams of different wavelengths to create a new beam with a frequency equal to the sum of the input frequencies. BBO is often used as the nonlinear crystal in SFG because of its high efficiency and low absorption. SFG is used in a range of applications, including in Raman spectroscopy and in the production of visible and ultraviolet light.
DFG produces a new frequency that is equal to the difference between two input frequencies. BBO can be used in DFG to generate tunable infrared radiation, which has applications in spectroscopy, sensing, and imaging.
BBO is also used in optical parametric oscillators (OPOs), which are devices that produce coherent light at a new frequency by using an input laser beam and a nonlinear crystal. OPOs using BBO crystals are useful for producing tunable infrared radiation, which has important applications in spectroscopy and imaging.
|Transparency range, nm||190 - 2600|
|Lattice parameters, Å||a = 12.532; c = 12.717 Å|
|at 1064 nm||ne = 1.5425; no = 1.6551|
|at 532 nm||ne = 1.5555; no = 1.6749|
|at 355 nm||ne = 1.5775; no = 1.7055|
|at 266 nm||ne = 1.6139; no = 1.7570|
|at 213 nm||ne = 1.6742; no = 1.8465|
|Non-linear coefficient, pm/V||d22 = 1.6; d31 = 0.08|
|Cut off SHG||Type I - 411 nm; Type II - 527 nm|
|Work off||Type I, 1064 nm - 3.2°|
|Temperature acceptance||Type I, 1064 nm - 55 °C "cm|
|Optical damage threshold||1 - 2 GW/cm2 (1064 nm, 10 ns)|
|Conversion efficiency, %||30 (1064 nm, 20 ns, 3 W)|
|35 (1780 nm, 20 ns, 20 Hz, 2 W)|
|20 (1064 nm, 20 ns, 50 Hz, 2 W)|