Lasers Crystals


KTP, short for Potassium Titanyl Phosphate, is widely used in SHG(second harmonic generating) of Nd-doped laser for green/red output. Is shows excellent nonlinear, electro-optical and acoustooptical properties.

CPG optics has 213 sets furnaces, and we could provide the super large size crystals as well for your special application.

KTP crystal is a standard with the parameters mostly used in extracavity configuration when the single pass through the crystal is required. By using extracavity KTP SHG, over 80% conversion efficiency and 700mJ green laser were obtained with a 900 mJ injection-seeded Q-switched Nd:YAG laser.

Another application for KTP crystals s the OPO/OPA, as a lot of research job was finished, it is quite popular for in this field, but for production, it requires a higher standard crystals quality as well. Why CPG optics developed the large size crystal grown, is now obviously.

CPG also cooperated with our China local research center for the quality confirmation from our production line set up in 2007. And we successfully won the local market as well as the international market.

  • Large nonlinear optical coefficient
  • Wide angular bandwidth and small walk-off angle
  • Broad temperature and spectral bandwidth
  • High electro-optic coefficient and low dielectric constant
  • Large figure of merit
  • No hydroscopic, chemically and mechanically stable
  • High thermal conductivity
  • Moisture free
  • Minimum mismatch gradient
  • Low cost compare with BBO and LBO

KTP Specifications:

  • Transmitting wavefront distortion: less than l/4 @ 633 nm
  • Dimension tolerance: (W ± 0.1 mm) x (H ± 0.1 mm) x (L + 0.2 mm/-0.1mm)
  • Clear aperture: > 90% central area
  • Flatness: l/8 @ 633 nm
  • Scratch/Dig code: 10/5 to MIL-O-13830A
  • Parallelism: better than 20 arc seconds
  • Perpendicularity: 5 arc minutes
  • Angle tolerance: Dq < ±0.5°, Df < ± 0.5°
  • AR coating: R< 0.2% at 1064nm and R<1.0% at 532 nm.
  • Quality Warranty Period: one year under proper use.

CPG OPTICS offers:

  • KTP crystal size up to 10010090 mm
  • Singleband and dualband AR and BBAR coatings
  • R&D of the new applications
  • Laser system design or OPO/OPA system design
  • Technical consulting


LBO crystal, Lithium Triborate, LiB3O5, is a nonlinear optical crystal. For frequency doubling (SHG) / tripling (THG) of Nd:YAG, Nd:YLF, Nd:YVO4 lasers, it is one of the most useful nonlinear optical materials in ultraviolet and visible laser applications.

Unique features of LBO crystal:

  • Broad transparency range from 160nm to 2600nm; SHG range from 550nm to 2600nm.
  • High optical homogeneity ( δν =€10-6/cm) and free of inclusion.
  • Relatively large effective SHG coefficient. (about three times that of KDP)
  • Excellent for high power and stable second-harmonic generation. (minimal thermal lensing compared to KTP)
  • High damage threshold. (18.9 GW/cm2 for a 1.3ns laser at 1053nm;25 GW/cm2 for a 10 ns laser at 1064 nm)
  • Wide acceptance angle and small walk-off.
  • Type I and type II non-critical phase matching (NCPM) in a wide wavelength range.
  • Spectral NCPM near 1300nm. LBO Crystal Applications:
  • Frequency doubling (SHG) and tripling (THG) of high power pulsed of Nd:YAG , Nd:YVO4, Nd:YLF, Ti:Sapphire and Dye lasers.
  • Optical parametric amplifiers (OPA) and oscillators (OPO) of both Type 1 and Type 2 phase-matching pumped by Excimer lasers and harmonics of Nd:YAG lasers.
  • Non-critical phase-matching (NCPM) for SHG 1064nm of laser.


Beta-barium borate (BBO) has the following exceptional properties that make it a very important nonlinear crystal.

BBO is grown with the flux method. It is a negative uniaxial crystal, with ordinary refractive-index (no) larger than extraordinary refractive-index (ne).

  • SHG phase-matching range from 410 nm to 2100 nm
  • Transmission from 190 nm to 3500 nm
  • Large effective nonlinear coefficient
  • High damage threshold
  • Wide temperature-bandwidth of about 55°C


BBO is of particular importance in the visible and far UV. A wide variety of phase-matching applications are possible, including the following:

  • Second, third, fourth and fifth harmonic generation of Nd doping lasers.
  • Frequency-doubling, -tripling and -mixing of Dye lasers.
  • Second, third and fourth harmonic generation of Ti:Sapphire lasers.
  • Optical parametric amplifier (OPA) and optical parametric oscillators (OPO).


  • BBO has a low susceptibility to the moisture. The user is advised to provide dry conditions for both the use and preservation of BBO.
  • BBO is relatively soft and therefore requires precautions to protect its polished surfaces.
  • When angle adjusting is necessary, keep in mind that the acceptance angle of BBO is small


Nd:YAG is the most important laser crystal. It is widely used in industrial, medical, military and scientific fields. CPG has been growing Nd:YAG laser crystal formore than 10 years. The advanced technique, highest volume capacity and complete capabilities for growing, fabrication, polishing and coating make CPG the leading manufacturer of Nd:YAG laser crystal in China.


  • High Gain, Low Threshold, High Efficiency
  • High damage threshold
  • High thermal conductivity
  • Low Loss at 1.06 um, High Optical Quality
  • Good Mechanical Properties

Nd:YAG Specifications:

  • Nd dopant level: 0.1- 2.5(+/-0.1)atm%
  • Orientation : <111> or <100>
  • Diameter: 1-30(+0/-0.05)mm
  • Length: 10-220(+/-0.5)mm(upon customer’s request)
  • Wavefront distortion: <λ/10 per inch@632.8nm
  • Chamfer: <0.1mm@45°
  • Chips: <0.1mm
  • Damage threshold: >750MW/cm2@1064nm 10ns 10HZ
  • Clear aperture: >95%
  • Flatness: λ/10 per inch@632.8nm
  • Scratch/Dig: 10-5 @MIL-0-13830A
  • Barrel finish: 50-80 micro-inch(RMS)
  • Chips: <0.1mm
  • Extinction ratio: >30dB(depends on actual sizes )
  • Perpendicularity: <5 arc minutes
  • Parallelism: <10 arc seconds
  • Anti-Reflection coating: R<0.15%@1064nm per surface