Cr: Forsterite crystal is a new tunable laser material that fills the spectral void in the near-IR region.  The tuning range covers the important spectral range from 1130nm to 1367nm, which provides a minimal dispersion in optical fibers.  The Cr: Forsterite laser eventually explores its niche applications for semiconductor characterization, eye-safe ranging, medical, industrial and scientific research.  Both pulsed, continuous-wave (CW) and fs laser operation have been obtained when pumped with 532, 578, 629 and 1064nm.  It can be also used as a passive Q-switch for solid state lasers, such as ruby laser, Alexandrite, Cr: LiSAF, etc.

Dream Lasers has developed the state of the art technology in growing the Cr: Forsterite crystal with the Czochralski method.  The standard Cr: Forsterite crystal with the dimensions of φ(3-10)×(10-30)mm are steadily available.  Other specifications, AR-coatings can be provided to meet your specific requirements.

Physical, Thermal and Optical Properties

Chemical Formula Cr: Mg2SiO4
Structure Orthorhombic, Pbnm
Gain Cross Section ~2×10-19 cm2
Corresponding Coefficient α=1.1, 1.5, 2.3cm-1@1064nm; 
α=8, 10, 12cm-1@733nm
Melting Point 1890℃
Density 3.22g/cm3
Mohs Hardness 7
Thermal Expansion Coefficient 9.5×10-6/K
Thermal Conductivity Gain Cross Section
Loss Coefficient <0.02 cm-1
Refractive Index 1.635
Surface damage threshold 9.5J/cm2 @ 6ns; 4.4J/cm2 @ 0.6ns


Spectroscopic and Laser Properties

Major Pumping Bands 850-1200, 600-850, 350-550nm
Fluorescence Band 680-1400nm
Room-temperature Fluorescence Lifetime ~3μs
Lasing Wavelength (center) 1235nm (pulsed), 1244nm (CW)
Typical Slope Efficiency 23% (pulsed), 38% (CW)
Tuning range 1130-1367nm
Gain Cross Section ~2×10-19 cm2
Absorption Section ~1.3×10-19 cm2