Lithium triborate

Lithium triborate
Identifiers
CAS number	12007-41-9 Y
Properties
Molecular formula	B3LiO5
Molar mass	119.37 g mol−1
Appearance	Colorless crystalline solid
Density	2.747 g/cm3
Melting point	834 °C, 1107 K, 1533 °F
Refractive index (nD)	1.5656
Structure
Molecular shape	Orthorhombic
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Lithium triborate (LiB₃O₅) LBO is a non-linear optics crystal. It has a wide transparency range, moderately high nonlinear coupling, high damage threshold and desirable chemical and mechanical properties. This crystal is often used for second harmonic generation (SHG, also known as frequency doubling) of Nd:YAG lasers (1064 nm → 532 nm). LBO can be both critically and non-critically phase-matched. In the latter case the crystal has to be heated or cooled depending on the wavelength.

Lithium triborate is an excellent nonlinear optical crystal discovered and developed by Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences. It has been patented.

Chemical properties

• Point group: mm2
• Lattice parameters: a=8.4473 Å, b=7.3788 Å, c=5.1395 Å
• Mohs hardness: 6
• Transmission range: 0.16 – 2.6 μm
• Damage threshold: 25 J/cm² (1064 nm, 10 ns pulses)
• Thermal expansion coefficients: x: 10.8×10⁻⁵/K, y: −8.8×10⁻⁵/K, z: 3.4×10⁻⁵/K
• Specific heat: 1060 J/kg·K
• Melting point: 834 °C

Applications of Lithium Triborate (LBO) Crystal

Lithium Triborate (LBO) crystals are applicable in various nonlinear optical applications:

• Frequency doubling (SHG) and frequency tripling of high peak power pulsed Nd doped, Ti:Sapphire lasers and Dye lasers
• NCPM (non-critical phase matching for frequecy conversion of CW and quasi CW radiation
• OPO (Optical Parametric Oscillators) of both Type 1 and Type 2 phase-matching

External links

• LBO Crystal (Lithium Triborate) at www.redoptronics.com