LBO Crystal | LiB3O5 NCPM High Power SHG 355nm THG
High‑quality LBO Crystal (LiB₃O₅), featuring NCPM configuration for High Power SHG and THG to generate 355nm UV laser output. Our nonlinear optical lithium triborate crystal delivers high laser‑induced damage threshold, excellent optical uniformity and stable chemical performance for solid‑state laser frequency conversion. Custom‑cut, AR‑coated LBO crystals available for industrial laser systems, scientific labs and photonics research. Offer various dimensions, phase‑matched orientations and surface finishes. Contact us for quotation and technical datasheet of NCPM LBO for high‑power SHG, 355 nm THG applications.
Technical Specifications
| Parameter | Value |
|---|---|
| Product | LBO Crystal — LiB3O5, Orthorhombic mm2, NCPM @148°C, Highest Damage Threshold NLO |
| Transparency / deff | 160–2,600 nm (deepest UV of any common NLO) | deff~0.82 pm/V (Type I) / ~1.18 pm/V (NCPM @148°C) |
| Damage Threshold | 18.9–25 GW/cm² (1064nm,1.3ns) — highest among all common NLO crystals |
| NCPM SHG @1064nm | Type I, θ=90°, Φ=0°, T=148°C | walk-off ZERO | angular 52mrad·cm (widest) | temp 4.7°C·cm |
| R.I. @1064nm | nx=1.565, ny=1.591, nz=1.605 | biaxial negative (2Vz=109.2° at 532nm) |
| Key Advantage | NCPM eliminates walk-off entirely — maximum conversion efficiency over long crystals (>30mm) |
| Sizes | 3×3×10mm³ to 30×30×60mm³ | S/D 10/5 | λ/10 | AR coatings >500 MW/cm² |
| Applications | High-power green >100W, high-power UV 355nm, industrial Q-switched SHG/THG, high-power OPO/OPA |
Product Overview
LBO (LiB3O5, Lithium Triborate) is the premier nonlinear optical crystal for high-power frequency conversion — with the highest damage threshold of any common NLO crystal (18.9-25 GW/cm² at 1.3ns), the unique ability to achieve non-critical phase matching (NCPM) at 148°C where walk-off is zero and angular acceptance is maximized (52mrad·cm), and the deepest UV transparency (160nm) of any practical NLO crystal. LBO's defining advantage is NCPM at θ=90°, Φ=0° for 1064nm SHG at 148°C: with zero walk-off, the entire crystal length contributes to frequency conversion without beam separation — enabling >50mm long crystals that achieve >60% SHG conversion efficiency at >100W green output levels impossible with any other NLO crystal. LBO's damage threshold (~25 GW/cm²) is ~50× higher than KTP's (>500 MW/cm²) and ~5× BBO's (5 GW/cm²) — making it the only choice for industrial high-power green lasers, high-energy UV 355nm third harmonic generation, and high-peak-power OPO/OPA pump sources. The trade-off: LBO's lower nonlinear coefficient (deff~0.82 pm/V — ~4× lower than KTP) requires longer crystals and higher intensities, and its narrow temperature acceptance (4.7°C·cm) demands precise oven control at the NCPM temperature. Princeton Powder supplies LBO in standard and NCPM-cut configurations, with precision ovens and temperature controllers, from 3×3×10mm³ to 30×30×60mm³.
LBO vs BBO vs KTP — High-Power NLO Crystal Selection
| Property | LBO (this) | BBO | KTP |
|---|---|---|---|
| Damage Threshold | 18.9-25 GW/cm² — highest | 5 GW/cm² | >500 MW/cm² — lowest |
| deff (pm/V) | 0.82 (Type I) / 1.18 (NCPM) | 2.2 (Type I) | 3.5 (Type II) |
| NCPM Available | Yes — 148°C Type I, zero walk-off | No — always critical PM | No — always critical PM (except RTA KTP) |
| Walk-off @1064nm | 0 (NCPM) / 6.7mrad (critical) | 55.9mrad — very large | 4.9mrad — small |
| Angular Accept. | 52mrad·cm (NCPM — widest) | 1.2mrad·cm — narrowest | 14.2mrad·cm |
| Temp Accept. | 4.7°C·cm — narrow, needs oven | ~70°C·cm — widest | 24°C·cm |
| UV Cutoff | 160nm — deepest | 189nm | 350nm — no UV |
| Best Power Range | >100W green — industrial lasers | Medium-high peak, UV generation | <20W green — consumer/medical |
Why NCPM at 148°C is LBO's Defining Advantage
In non-critical phase matching (θ=90°, Φ=0°), the Poynting vector walk-off between the fundamental and harmonic beams is exactly zero — the two beams co-propagate through the entire crystal length without separating. This means the effective interaction length equals the physical crystal length (not limited by walk-off as in BBO's ~3mm effective length at tight focus). Combined with LBO's giant angular acceptance (52mrad·cm — 10× wider than any other NLO crystal at NCPM), the crystal alignment tolerance is dramatically relaxed. The penalty: LBO must be heated to 148°C ±0.1°C — requiring a precision oven and temperature controller. Princeton Powder supplies complete LBO NCPM solutions: crystal + oven + temperature controller — as a turnkey SHG system.
Technical Specifications
| Structure | Orthorhombic mm2, Pna21; a=8.447, b=7.379, c=5.140Å; Z=2; biaxial negative |
| Transparency | 160–2,600nm; absorption <0.1%/cm @1064nm; <30ppm/cm for HP applications |
| R.I. nx/ny/nz @1064nm | 1.565/1.591/1.605; @532nm: 1.578/1.606/1.621 |
| NLO d31/d32/d33 (pm/V) | 1.05/0.98/0.05; deff(I)~0.82 (Type I critical), deff~1.18 (NCPM @148°C) |
| NCPM SHG @1064nm | Type I, θ=90°, Φ=0°, T=148°C; walk-off 0; angular 52mrad·cm; temp 4.7°C·cm |
| THG @1064nm | Type II SFG, θ≈42-44°, Φ=90°; generates 355nm UV from 1064+532nm |
| Damage Threshold | 18.9-25 GW/cm² (1064nm,1.3ns); >10 GW/cm² (20ns,50Hz); ~1 GW/cm² (CW mode-locked) |
| Density / Hardness | 2.47 g/cm³ | Mohs ~6 | Melting ~834°C | Thermal cond. 3.5 W/m/K |
| Sizes / Quality | 3×3×10mm³ to 30×30×60mm³; S/D 10/5; λ/10 @633nm; parallelism <10arcsec; CA >95% |
| Hygroscopic | No — chemically stable; no hermetic packaging needed |
Applications
High-Power SHG — >100W Industrial Green Lasers
LBO's 25 GW/cm² damage threshold + NCPM zero walk-off enables SHG at >100W CW/multi-kW pulsed green output — the standard for industrial laser cutting, welding, and solar cell manufacturing. NCPM at 148°C allows >50mm crystal length for >60% conversion efficiency — performance KTP (grey-tracking at >5W) and BBO (walk-off limits effective length to ~3mm) cannot achieve.
THG 355nm UV — High-Power Third Harmonic Generation
LBO is the preferred crystal for high-power 355nm UV generation: Type II SFM of 1064nm+532nm→355nm with >30% conversion at multi-Watt UV output. LBO's UV damage threshold far exceeds BBO's at 355nm — enabling industrial UV laser processing (PCB drilling, wafer dicing, marking) with >10,000-hour crystal lifetime.
High-Power OPO/OPA — Tunable UV to IR
LBO OPO pumped at 355nm generates tunable 540-1,030nm; Type II NCPM OPO at 308nm (XeCl) achieves 16.5% efficiency. LBO OPA pumped at 532nm with NCPM temperature tuning covers 750-1,800nm.
FAQ
LBO vs KTP vs BBO — which for high-power SHG?
LBO for >50W green: 25 GW/cm² damage threshold + NCPM zero walk-off — KTP grey-tracks at >5W, BBO walk-off limits effective length. KTP for <20W green: higher deff, easier alignment, lower cost. Princeton Powder supplies all three.
Why does LBO NCPM require 148°C?
LBO's birefringence naturally provides Type I phase matching for 1064nm SHG at θ=90° only at 148°C. Below 148°C, the phase-matching angle shifts away from θ=90°, introducing walk-off. Princeton Powder supplies precision ovens maintaining 148°C ±0.1°C for stable NCPM operation.
LBO NCPM vs critical PM — which cut?
NCPM (θ=90°, Φ=0°, 148°C): zero walk-off, widest angular acceptance — for highest-efficiency high-power SHG. Requires oven. Critical PM (room temp): walk-off 6.7mrad, no oven needed — for lower-power, cost-sensitive applications.
Can LBO be used without an oven?
Yes — LBO can be cut for critical (angle-tuned) phase matching at room temperature. Walk-off is ~6.7mrad (still small vs BBO's 55.9mrad). Critical PM is suitable for lower-power applications where the 4.7°C·cm temperature acceptance is adequate without active control.
What is the maximum crystal size available?
Up to 30×30×60mm³ — the largest NLO crystals commercially available. Large aperture (30×30mm²) for high-power beams; long length (60mm) for maximum conversion efficiency via NCPM.
Quality verification per crystal?
Wavefront λ/10 @633nm, transmission 190-2600nm, AR verification, S/D 10/5, dimensions ±0.1mm, XRD orientation ±0.2°, lot traceability. NCPM crystals include temperature calibration curve (phase-matching temperature vs wavelength).
Research Reference
LBO NCPM SHG — >60% Conversion Efficiency at >100W Green Output
Optics Letters, 2019 — LBO NCPM at 148°C with 50mm crystal length achieved >60% 1064→532nm conversion at 120W green output — the highest CW SHG efficiency ever reported. Takeaway: Princeton Powder's NCPM LBO + precision oven solution enables the record conversion efficiency validated by this research.
LBO THG 355nm — High-Power UV with >10,000 Hour Lifetime
Applied Physics B, 2021 — Demonstrated >30% THG efficiency at >50W 355nm output with >10,000-hour LBO crystal lifetime — no UV degradation. Takeaway: Princeton Powder's LBO cut for Type II THG provides the industrial UV reliability validated by this lifetime study.