Generation of Red Light Femtosecond Pulses from an Intra-Cavity Frequency-Doubled Cr 4+ : Forsterite Laser

We demonstrate the generation of red light femtosecond laser pulses from an intra-cavity frequency-doubled Cr 4+ :forsterite laser. An average output power of 75 mW is obtained at the central wavelength of 647 nm with a pulse width of 55 fs by inserting a 500-μm-thick BBO crystal in the laser cavity. The bandwidth of the spectrum of second harmonic pulses is 9 nm, corresponding to a time-bandwidth product of 0.355.