The vibronic laser material Cr:Forsterite fills the void in the near-infrared region (1.15-1.3 μm) not covered by any other solid-state laser. In this system, the large laser bandwidth has been utilized to generate sub-100 fs pulses by modelocking. Since the tuning range of Ti:Sapphire is limited to below 1 μm, the Cr:Forsterite system will be important for scientific and medical applications where a source further into the near-infrared is needed. The operating wavelength of this system coincides with a dip in the absorption of water and, in addition, a low scattering regime, making Cr:Forsterite an important source for imaging applications.
Cr:Forsterite was first lased in the late 1980’s, and has been shown to be an important source of near-infrared radiation. By accessing the inherent Kerr nonlinearity of the Cr:Forsterite laser crystal, it is possible to generate ultrashort pulses using a technique known as self-modelocking. In an optimized cavity configuration, sub-100 fs pulses are generated. In this laser, the use of a prism pair, to introduce negative dispersion, results in the production of pulses as short as 36 fs.