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  • Alexandrite Laser Crytstals
  • Alexandrite Laser Crytstals
  • Alexandrite Laser Crytstals
  • Alexandrite Laser Crytstals
  • Alexandrite Laser Crytstals
  • Alexandrite Laser Crytstals

Alexandrite Laser Crytstals

  • Eminent for long pulsed, Q-swithed or pico second 755nm laser
  • High damage threshold (capable of withstanding >1.5 million pulses
  • High thermal shock resistance and wide wavelength emission range
  • Refurbishing service (re-polishing and re-coating) for used alexandrite rods
  • DKDP 755nm Pockels Cells available
Inquire Us  

Typical modules:

Dia5x115mm,  Dia7x110mm,  Dia7x125mm

Dia6.35x120mm,  Dia8x130mm,  Dia9.53x117mm 


Specifications:

Size Tolerance Diameter (+0/-0.05 mm) x Length (+1/-0 mm)
Surface Quality 10/5 S/D Parallelism <10”
Allowed Chips <0.1mm Perpendicularity <5'
Flatness λ/10@633nm Clear Aperture ≥98%
Coating Options 1- Normal : AR@755nm on both ends 2- Mirror coating: HR@755nm(S1) & PR@755nm(S2)
Optional End Forms of Rod 1- Plano-Plano 2- Convex-Plano
Damage Threshold > 1.5 Million pulses ( tested by third party)


Material Properties:

Fomula Cr3+:BeAl2O4
Lattice Constants (Angstrom)​ 5.476(a) x 9.404(b) x 4.427(c)
Molecular weight 127.01 g/mole
Hardness (Mohs) 8.5
Lasing wavelength 710 - 800 nm
Crystal System Orthorhombic
Refractive Index (@750 nm) 1.7367(a) x 1.7241(b) x 1.7346(c)
Thermal Expansion Coefficient (x 10^-6/K) 5.9(a), 6.1(b), 6.7(c)
Vickers Hardness(kg/mm^2) 2000
Melting Point 1870 °C
Thermal Conductivity 0.23 W/cm•K
Density 3.7 g/cm^3
Young's Modulus (GPa) 469
Thermal Shock Resistance (W/cm) 35 - 74
dn/dT 8x10^-6/K

Alexandrite (chromium-doped beryllium aluminate, Cr3+:BeAl2O4) is a kind of crystalline laser gain medium grown in monocrystalline form using the improved Czochralski method, and the laser-active Cr3+ ions are doped in the host crystal. Alexandrite laser crystal is capable of generating wide wavelength range emissions, a tuning range of 710nm to 800nm is possible under optimum operating conditions, the most extensively applied wavelength being around 755nm, where maximum efficiency could be attained. Alexandrite laser crystal is a topical material currently for applications in various industrial fields including Dermatology, Atmospheric Lidar, or Spectroscopy (which exploits the wavelength tunability of Alexandrite), etc. And is especially advantageous for Medical Laser Devices (e.g. Hair Removal Lasers). Additionally, attributing to highly anisotropic structure, combined with its significant birefringent property, it is possible to achieve linearly polarized emission of low depolarization loss with Alexandrite laser.

Hangzhou Shalom offers customized Alexandrite laser crystals favorable for 755nm long pulsed,  Q-switched or pico second lasers,  with high damage threshold, high thermo-optical quality and competitive price. We also provide refurbishing service (re-polishing and re-coating for used laser rods). Incidentally,  You could get the complementary DKDP 755nm Pockels Cells for your Alexandrite laser in Shalom EO, fast delivery is guaranteed for your requirements. 

Features and applications of Alexandrite Laser Crystal:

  • High thermal shock resistance

Alexandrite not only endure high temperature, but even achieve higher laser gain and efficiency under elevated temperature . The Alexandrite provided possesses excellent thermo-mechanical and thermo-optical properties. Comparing to Nd:YAG, the thermal shock resistance of Alexandrite is five times higher.

  • High damage threshold

The Alexandrite rod provided by Shalom EO have a high damage threshold that enables the rod to withstand >1.5million pulses.

  • Excellent for 755nm long pulsed, Q-Switched or pico second lasers

Hangzhou Shalom offers customized Alexandrite laser crystals favorable for 755nm long pulsed,  Q-switched or pico second lasers, you could also get the DKDP 755nm Pockels Cells in Shalom EO. This wavelength could be thoroughly absorbed by the hairs as well as melanin, making it favorable for aesthetic laser systems.

  • Hair removal machines or Tattoo removal systems

In the Case of hair removal, Alexandrite laser is a better choice than diode laser for people with lighter skin, however for people with dark skin tone diode laser might be the only option since Alexandrite laser has a higher potential of causing damage to darker skin.Comparing to Nd:YAG laser, Alexandrite laser is advantageous for poeple with lighter hair, and in terms of tolerability, it is generally found to be less painful than the Nd:YAG.

Tattoos can be removed by applying light which can be absorbed by the used ink, which is then chemically transformed and subsequently removed by the body. Q-switched short pulse Alexandrite laser is favorable for small ink particles.

Curves:

1. Absorption Curves of Alexandrite Crystals



2. Transmission Curves of High Reflection and Partial Reflection Coatings for Alexandrite Rods

1). Typical Transmission Rates of High Reflection (HR) Coatings


 


2). Typical Transmission Rates of Partial Reflection (PR) Coatings