Ultrafast dynamics of non-epitaxially grown semiconductor-doped silica film saturable absorbers

Summary form only given. Semiconductor saturable absorbers are a widely used technology for generating femtosecond pulses in solid state lasers, providing advantages such as self-starting operation and the potential for compact laser cavities. The most common semiconductor saturable absorber devices are fabricated by molecular beam epitaxy (MBE) and have been used for both saturable absorber modelocking and initiation of Kerr lens modelocking (KLM) in many solid state laser systems. However, MBE has disadvantages including high complexity and cost as well as lattice matching constraints that limit material choice. Recently, we have developed non-epitaxially grown saturable absorber devices and applied them to self-starting KLM in a Ti:Al/sub 2/O/sub 3/ laser. The devices consist of InAs nanocrystallites doped into SiO/sub 2/ films and deposited on sapphire substrates using a non-magnetron radio frequency (RF) sputtering system. The current work focuses on methods for reducing the saturation fluence in these devices.