Related link: LBO Crystal Components
LBO Crystal Basic Properties
LBO Crystal Physical Properties
Crystal Structure 
Orthorhombic, Space group Pna2_{1}, Point group mm2 
Lattice Parameter 
a=8.4473Å, b=7.3788Å , c=5.1395Å , Z=2 
Melting Point 
About 834℃ 
Mohs Hardness 
6 
Density 
2.47 g/cm^{3} 
Thermal Conductivity 
3.5W/m/K 
Thermal Expansion Coefficient 
a_{x}=10.8x10^{5}/K, a_{y}= 8.8x10^{5}/K, a_{z}=3.4x10^{5}/K 
LBO Optical and Nonlinear Optical Properties
Transparency Range 
1602600nm 
SHG Phase Matchable Range 
551 ~ 2600nm (Type I), 
Thermoptic Coefficient (°C, λ in μm) 
dnx/dT=9.3X10^{6}, 
Absorption Coefficient 
<0.1%/cm at 1064nm, 
Angle Acceptance 
6.54mrad/cm (φ, Type I,1064 SHG), 
Temperature Acceptance 
4.7°C/cm (Type I, 1064 SHG), 
Spectral Acceptance 
1.0nm/cm (Type I, 1064 SHG), 
Walkoff Angle 
0.60° (Type I 1064 SHG), 
NLO Coefficients 
d_{eff}(I)=d_{32}cosΦ (Type I in XY plane), 
Nonvanished NLO susceptibilities 
d_{31}=1.05 ± 0.09 pm/V, d_{32}= 0.98 ± 0.09 pm/V, d_{33}=0.05 ± 0.006 pm/V 
Sellmeier Equations(λ in μm) 
n_{x}^{2}=2.454140+0.011249/(λ^{2}0.011350)0.014591λ^{2}6.60x10^{5}λ^{4}, 
LBO's Harmonic Generation Applications:
SHG conversion efficiencies of more than 70% for pulse and 30% for cw Nd:YAG lasers, and THG conversion efficiency over 60% for pulse Nd:YAG laser have been observed by using high quality LBO crystal.
More than 480mW output at 395nm is generated by frequency doubling a 2W modelocked Ti:Sapphire laser (<2ps, 82MHz). The wavelength range of 700900nm is covered by a 5x3x8mm3 LBO crystal.
Over 80W green output is obtained by SHG of a Qswitched Nd:YAG laser in a type II 18mm long LBO crystal.
The frequency doubling of a diode pumped Nd:YLF laser (>500µJ @ 1047nm, <7ns, 010KHz) reaches over 40% conversion efficiency in a 9mm long LBO crystal.
The VUV output at 187.7 nm is obtained by sumfrequency generation.
2mJ/pulse diffractionlimited beam at 355nm is obtained by intracavity frequency tripling a Qswitched Nd:YAG laser.
LBO's NonCritical PhaseMatching
Table 3. Properties of type I NCPM SHG at 1064nm 

NCPM Temperature 
148°C 
Acceptance Angle 
52 mradcm^{1/2} 
Walkoff Angle 
0 
Temperature Bandwidth 
4°Ccm 
Effective SHG Coefficient 
2.69 d_{36}(KDP)Bottom of Form 
AS shown in table 3, NonCritical PhaseMatching (NCPM) of LBO is featured by no walkoff, very wide acceptance angle and maximum effective coefficient. It promotes LBO to work in its optimal condition. SHG conversion efficiencies of more than 70% for pulse and 30% for cw Nd:YAG lasers have been obtained, with good output stability and beam quality.
Type I and type II noncritical phasematching can be reached along xaxis and zaxis at room temperature, respectively.(The assembly of oven and temperature controller is recommended for NCPM applications).
By using LBO crystal,over 11W of average power at 532nm was obtained by extracavity SHG of a 25W Antares modelocked Nd:YAG laser (76MHz, 80ps).
By using LBO crystal,20W green output was generated by frequency doubling a medical, multimode Qswitched Nd:YAG laser. Much higher green output is expected with higher input.
LBO’s OPO and OPA
LBO is an excellent NLO crystal for OPOs and OPAs with a widely tunable wavelength range and high powers. These OPO and OPA that are pumped by the SHG and THG of Nd:YAG laser and XeCl excimer laser at 308nm have been reported. The unique properties of type I and type II phase matching as well as the NCPM leave a big room in the research and applications of LBO’s OPO and OPA. Fig.4 shows the calculated type I OPO tuning curves of LBO pumped by the SHG, THG and 4HG of Nd:YAG laser in XY plane at the room temperature. And Fig. 5 illustrates type II OPO tuning curves of LBO pumped by the SHG and THG of Nd:YAG laser in XZ plane.
A quite high overall conversion efficiency and 5401030nm tunable wavelength range were obtained with OPO pumped at 355nm.
Type I OPA pumped at 355nm with the pumptosignal energy conversion efficiency of 30% has been reported.
Type II NCPM OPO pumped by a XeCl excimer laser at 308nm has achieved 16.5% conversion efficiency, and moderate tunable wavelength ranges can be obtained with different pumping sources and temperature tuning.
By using the NCPM technique, type I OPA pumped by the SHG of a Nd:YAG laser at 532nm was also observed to cover a wide tunable range from 750nm to 1800nm by temperature tuning from 106.5°C to 148.5°C.
By using type II NCPM LBO as an optical parametric generator (OPG) and type I critical phasematched BBO as an OPA, a narrow linewidth (0.15nm) and high pumptosignal energy conversion efficiency (32.7%) were obtained when it is pumped by a 4.8mJ, 30ps laser at 354.7nm. Wavelength tuning range from 482.6nm to 415.9nm was covered by increasing the temperature of LBO or rotating BBO.
LBO’s Spectral NCPM
Not only the ordinary noncritical phase matching (NCPM) for angular variation but also the noncritical phase matching for spectral variation (SNCPM) can be achieved in the LBO crystal. As shown in Fig.2, the phase matching retracing positions are λ1=1.31μm with θ =86.4°, φ=0° for Type I and λ2=1.30μm with θ=4.8°, φ=0° for Type II. The phase matching at these positions possess very large spectral acceptances Δλ. The calculated Δλ at λ1 and λ2are 57nmcm1/2 and 74nmcm1/2 respectively, which are much larger than the other NLO crystals. These spectral characteristics are very suitable for doubling broadband coherent radiations near 1.3μm, such as those from some diode lasers, and some OPA/OPO output without linewidthnarrowing components.
The crystal holder(free) and oven & Temperature Controller (for NCPM,OPO,OPA applications) are available for BBO & LBO.