title: Intra-cavity gain shaping of mode-locked Ti:sapphire laser oscillations.
abstract: The gain properties of an oscillator strongly affect its behavior. When the gain is homogeneous, different modes compete for gain resources in a 'winner takes all' manner, whereas with inhomogeneous gain, modes can coexist if they utilize different gain resources. We demonstrate precise control over the mode competition in a mode locked Ti:sapphire oscillator by manipulation and spectral shaping of the gain properties, thus steering the competition towards a desired, otherwise inaccessible, oscillation. Specifically, by adding a small amount of spectrally shaped inhomogeneous gain to the standard homogeneous gain oscillator, we selectively enhance a desired two-color oscillation, which is inherently unstable to mode competition and could not exist in a purely homogeneous gain oscillator. By tuning the parameters of the additional inhomogeneous gain we flexibly control the center wavelengths, relative intensities and widths of the two colors.
authors.affiliation: Department of physics and BINA Center of nano-technology, Bar-Ilan university, Ramat-Gan 52900, Israel.
authors.forename: Shai
authors.initials: S
authors.lastname: Yefet
authors.forename: Na'aman
authors.initials: N
authors.lastname: Amer
authors.forename: Avi
authors.initials: A
authors.lastname: Pe'er
mesh_terms: D000537:Aluminum Oxide; D000669:Amplifiers, Electronic; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005246:Feedback; D007834:Lasers; D009991:Oscillometry / Q000295:instrumentation*
chemical_list: D000537:Aluminum Oxide