β phase metabarium metaborate (BBO) crystal can transmit a wide range of wavelengths (190-3500nm), especially the ultraviolet band has good transmission, the disadvantage is that it has a small receiving angle and a large divergence angle, BBO crystal has a high damage domain value, suitable for high power, good optical uniformity, is a highly efficient nonlinear crystal.

It can be widely used in different types of lasers such as dye lasers, ultrafast pulse lasers, titanium sapphire, argon ion lasers and copper vapor lasers, such as 1064nm and 800nm two, third and quadruple frequency, in addition, the OPO and OPA systems of BBO crystals can also be used to produce a wide range of tunable coherent optical output from ultraviolet to infrared, with good electro-optical effect, and are also a kind of electro-optical crystal that is most commonly made into electro-optical Q-modulation and modulation devices.

General parameters

Form Tolerance(mm)	±0.1	Length tolerance(mm)	±0.2
Effective aperture	>90%	Face	＜λ/8@633nm
Through wavefront distortion	＜λ/4@633nm	Eccentricity	＜20〞
Side verticality	＜5ˊ	Finish	20/10
Chamfering	Protective＜0.1mm×45°	End face coating	Both end faces are coated with anti-reflection film, and the residual reflectivity on one side is residual R＜0.5%@532&1064nm

Peculiarity

Very superior physical and mechanical properties
Wide band range for phase matching (410-3500nm)
Wide light transmission range (190-3500nm)
High frequency doubling conversion efficiency (6 times KDP)
High damage threshold
Good optical uniformity
Wide temperature reception angle (55°)

Physical and optical properties

Crystal structure		Trigonal crystal system, space group R3c
Lattice parameters		a=b=12.532Å, c=12.717Å, Z=6
Melting point		1095±5℃
Curie Point		925±5℃
Optical uniformity		10^-6/cm
Mohs hardness		4.5
Density		3.85g/cm³
Linear absorption coefficient		＜0.1%/cm (at 1064 nm)
Deliquescence		Low
Resistivity		＞10¹¹ ohm/cm
Relative dielectric constant		e^T₁₁/e₀: 6.7, e^T₃₃/e₀: 8.1 Tan d, ＜ 0.001
Warm light coefficient(25-900℃)		⊥c, 4 x 10^-6/K; \|\|c, 36 x 10^-6/K
Thermal conductivity		⊥c, 1.2 W/m/K; \|\|c, 1.6 W/m/K
Transmission range		189-3500 nm
Thermophotovoltaic coefficient		dn_o/dT=-9.3x10^-6/⁰C; dn_e/dT=-16.6x10^-6/⁰C
Nonlinear coefficients		d₁₁=5.8xd₃₆(KDP) d₃₁=0.05xd₁₁, d₂₂<0.05xd₁₁
Electro-optical coefficient		g₁₁=2.7 pm/V, g₂₂, g₃₁<0.1 g₁₁
Half-wave voltage		48 KV (at 1064nm)
Frequency doubling phase matching band		189-1750nm
Damage threshold	@1.064um	5 GW/cm² (10 ns); 10 GW/cm² (1.3 ns)
	@0.532um	1 GW/cm² (10 ns); 7 GW/cm² (250 ps)
	@0.266um	120 MW/cm² (8ns)
Sellmeier equation (λ in um)		n_o²(λ)=2.7359+0.01878/(λ²-0.01822)-0.01354λ² n_e²(λ)=2.3753+0.01224/(λ²-0.01667)-0.01516λ²

Size（mm）	5×510×104×4
Length （mm）	7100.10.3-0.512
θ(°)	22.847.629.2
Coating	两面增透@532&1064nm两面增透@266&532nm两面增透@400&800nm
Application	SHG@1064,Type I4HG@1064,Type ISHG@800,Type I