%0 Journal Article %T Semiconductor Disk Lasers: Recent Advances in Generation of Yellow-Orange and Mid-IR Radiation %A Mircea Guina %A Antti H£¿rk£¿nen %A Ville-Markus Korpij£¿rvi %A Tomi Leinonen %A Soile Suomalainen %J Advances in Optical Technologies %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/265010 %X We review the recent advances in the development of semiconductor disk lasers (SDLs) producing yellow-orange and mid-IR radiation. In particular, we focus on presenting the fabrication challenges and characteristics of high-power GaInNAs- and GaSb-based gain mirrors. These two material systems have recently sparked a new wave of interest in developing SDLs for high-impact applications in medicine, spectroscopy, or astronomy. The dilute nitride (GaInNAs) gain mirrors enable emission of more than 11£¿W of output power at a wavelength range of 1180¨C1200£¿nm and subsequent intracavity frequency doubling to generate yellow-orange radiation with power exceeding 7£¿W. The GaSb gain mirrors have been used to leverage the advantages offered by SDLs to the 2¨C3£¿¦Ìm wavelength range. Most recently, GaSb-based SDLs incorporating semiconductor saturable absorber mirrors were used to generate optical pulses as short as 384£¿fs at 2£¿¦Ìm, the shortest pulses obtained from a semiconductor laser at this wavelength range. 1. Introduction Conceptually, the idea of an optically pumped semiconductor disk laser (OP-SDLs) was suggested already in 1966 by Basov et al. in a paper describing lasers with radiating mirrors [1]. However, it was not until the 1990s that the concept was acknowledged and the first working devices were reported [2¨C6]. In its essence, the concept of an OP-SDL is based on using an optically pumped semiconductor gain structure (i.e., gain mirror) with vertical emission. We note here that in addition to OP-SDL, also acronyms like OP-VECSEL (optically pumped vertical external-cavity surface-emitting laser) and OPSL (optically pumped semiconductor laser) are commonly used in literature to describe the same type of laser. The laser resonator is typically formed between the gain mirror and one or more external-cavity mirrors. In many ways, this laser architecture is similar to that of traditional solid state disk lasers. An essential difference is that in traditional solid state lasers the emission wavelength is dependent on certain fixed atomic transitions in a host material, whereas in an SDL the wavelength can be specifically tailored in a wide range by engineering the composition of the semiconductor material. This added wavelength versatility is one of the key factors that have made SDLs successful also commercially. Technically speaking, the OP-SDL can be considered as a brightness and wavelength converter; it converts low brightness light from multimode diode pump lasers into a high brightness single mode beam at a wavelength that is longer than the pump %U http://www.hindawi.com/journals/aot/2012/265010/