ABSTRACT
This chapter provides an overview of the physics of these new all-solid-state ultrafast lasers. Shorter pulse durations, down to 6fs, were achieved only through additional amplification and fibre-grating pulse compression at much lower repetition rates. The development of higher average-power diode lasers in the 1980s stimulated a strong interest in diode-pumped solid-state lasers. Diode laser pumping provides dramatic improvements in efficiency, lifetime, size and other important laser characteristics. The concept is that the ultrashort pulses from the oscillator are temporarily stretched, usually using a pair of suitably oriented diffraction gratings. A homogeneously broadened laser normally tends to oscillate in only one axial mode when far above the laser threshold. The physics of laser pulse generation is very well explained with Haus’s master equation formalism. In the case of an ideal fast saturable absorber we assume that the loss q recovers instantaneously and therefore shows the same time dependence as the pulse envelope.
