LBO-Nonlinear crystal-Beijing Honour Optics Co., Ltd-Honour Optics Co., Ltd

LBO

Lithium Triborate (LBO) is unique in many aspects, especially its wide transparency range, moderately high nonlinear coupling, high damage threshold and good chemical and mechanical properties. LBO allows temperature-controllable non -critical phase-matching (NCPM) for 1.0-1.3 μm, Type I SHG, and also provides room temperature NCPM for Type II SHG at 0.8-1.1 μm. It possesses a relatively large angular acceptance bandwidth, reducing the beam quality requirements for source lasers.

Specifications:

* Dimension tolerance: (W±0.1mm)x(H±0.1mm)x(L+0.5/-0.1mm) (L≥2.5mm)
                                      (W±0.1mm)x(H±0.1mm)x(L+0.1/-0.1mm) (L<2.5mm)
* Clear aperture: central 90% of the diameter
* 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
* Scratch/Dig code: better than 10/ 5 to MIL-PRF-13830B
* Parallelism: better than 20 arc seconds
* Perpendicularity: ≤5 arc minutes
* Angle tolerance: Δθ≤0.25°, ΔΦ≤0.25°
* Damage threshold[GW/cm2 ]: >10 for 1064nm, TEM00, 10ns, 10HZ (polished only)
                                                     >1 for 1064nm, TEM00, 10ns, 10HZ (AR-coated)
                                                     >0.5 for 532nm, TEM00, 10ns, 10HZ (AR-coated)
* Quality Warranty Period: one year under proper use.

Table 1. Chemical and Structural properties of LBO

Crystal Structure	Orthorhombic, Space group Pna21, 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/cm3
Thermal Conductivity	3.5W/m/K
Thermal Expansion Coefficient	ax=10.8x10-5/K, ay= -8.8x10-5/K, az=3.4x10-5/K

Table 2. Optical and Nonlinear Optical Properties of LBO

Transparency Range	160-2600nm
SHG Phase Matchable Range	551 ~ 2600nm (Type I) 790-2150nm (Type II)
Therm-optic Coefficient (°C, λ in μm)	dnx/dT=-9.3X10-6 dny/dT=-13.6X10-6 dnz/dT=(-6.3-2.1λ)X10-6
Absorption Coefficient	<0.1%/cm at 1064nm <0.3%/cm at 532nm
Angle Acceptance	6.54mrad-cm (φ, Type I,1064 SHG) 15.27mrad-cm (q, Type II,1064 SHG)
Temperature Acceptance	4.7°C-cm (Type I, 1064 SHG) 7.5°C-cm (Type II,1064 SHG)
Spectral Acceptance	1.0nm-cm (Type I, 1064 SHG) 1.3nm-cm (Type II,1064 SHG)
Walk-off Angle	0.60° (Type I 1064 SHG) 0.12° (Type II 1064 SHG)
NLO Coefficients	deff(I)=d32cosΦ (Type I in XY plane) deff(I)=d31cos2θ+d32sin2θ (Type I in XZ plane) deff(II)=d31cosθ (Type II in YZ plane) deff(II)=d31cos2θ+d32sin2θ (Type II in XZ plane)
Non-vanished NLO susceptibilities	d31=1.05 ± 0.09 pm/V d32= -0.98 ± 0.09 pm/V d33=0.05 ± 0.006 pm/V
Sellmeier Equations(λ in μm)	nx2=2.454140+0.011249/(λ2-0.011350)-0.014591λ2-6.60x10-5λ4 ny2=2.539070+0.012711/(λ2-0.012523)-0.018540λ2+2.0x10-4λ4 nz2=2.586179+0.013099/(λ2-0.011893)-0.017968λ2-2.26x10-4λ4