Ultra-Short Pulse Ho:YAG Slab Amplifier for Laser Processing of Infrared Optical Materials

Silicon is of significant interest for widely used opto-electronics components [1]. While there are a number of well-established manufacturing techniques for Si, there remains a gap in capabilities: i.e. laser-written internal modification. Such a capability would enable new techniques e.g. selective etching, waveguide inscription and ultra-short pulse (USP) laser welding. The gap is due to a lack of suitable USP lasers at relevant, 2.0-2.2 μm wavelengths [2]. Commercial mode-locked fibre lasers in this wavelength range are typically limited to ps pulses with a few hundred mW average power, at MHz repetition rates, i.e. 10-100's ofnJ pulses whereas <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu \mathrm{J}$</tex> pulses are required for such processes. The output power and pulse energy necessary for these applications [3] hence requires development of solid-state lasers capable of producing an average output in the 10 to 100 W range.