Appl. Phys. Lett. 103, 051114 (2013)
There is a pressing need to find convenient and effective ways to generate deep ultraviolet light for techniques such as photoemission spectroscopy and semiconductor lithography. Frequency conversion of the output of continuous-wave diode and solid-state lasers is one approach, but reaching wavelengths shorter than 200 nm has proved problematic because of the limitations of nonlinear crystals. Now, Matthias Scholz and co-workers from Germany and China have produced a continuous-wave laser source that can achieve a high output power of over 15 mW at 193 nm. Their scheme quadruples the frequency of the 772-nm output of a diode laser in two stages; both stages consist of an enhancement cavity containing a crystal — a lithium triborate crystal in the first stage and a potassium fluoro-beryllo-borate crystal in the second stage. The researchers demonstrate that this laser can produce a stable output of 8 mW over a period of 80 h and that its short-term noise characteristics are superior to those of excimer lasers by one order of magnitude. It is thus a promising replacement for ArF excimer lasers for both scientific and commercial applications, potentially offering superior coherence properties, spectral density, reliability and ease of use.
Rights and permissions
About this article
Cite this article
Pleasants, S. Excimer replacement. Nature Photon 7, 763 (2013). https://doi.org/10.1038/nphoton.2013.264
Published:
Issue Date:
DOI: https://doi.org/10.1038/nphoton.2013.264