Fiber chirped pulse amplification system for micromachining

Chirped Pulse Amplification (CPA) is widely used for generating high-energy femtosecond pulses. This is most commonly done with a solid-state Ti:Sapphire crystal through a free-space optical path. The high energy density in the crystal and the precise optical path required with the use of bulk optics make it difficult to design a simple system with good stability and beam quality over the environmental conditions typically encountered in the manufacturing environment. A CPA system using fiber architecture reduces the need for precise beam guiding since the light follows the fiber. The pump energy is more evenly distributed along the length of the amplifier fiber, reducing the thermal dissipation that is required (no water chiller is required) and improving the overall efficiency. The fiber architecture also produces a superior quality beam that does not require great care to maintain. IMRA's latest FCPA μJewel uses the inherent advantages of the FCPA architecture, along with extensive engineering, to produce a compact and stable femtosecond fiber laser system. Its high repetition rate and stable performance enables applications that were difficult to achieve previously. This paper will review the general design architecture of the FCPA μJewel and discuss several applications.