title: Spectral characteristics of quantum-cascade laser operating at 10.6 μm wavelength for a seed application in laser-produced-plasma extreme UV source.
abstract: In this Letter, we investigate, for the first time to our knowledge, the spectral properties of a quantum-cascade laser (QCL) from a point of view of a new application as a laser seeder for a nanosecond-pulse high-repetition frequency CO(2) laser operating at 10.6 μm wavelength. The motivation for this work is a renewed interest in such a pulse format and wavelength driven by a development of extreme UV (EUV) laser-produced-plasma (LPP) sources. These sources use pulsed multikilowatt CO(2) lasers to drive the EUV-emitting plasmas. Basic spectral performance characteristics of a custom-made QCL chip are measured, such as tuning range and chirp rate. The QCL is shown to have all essential qualities of a robust seed source for a high-repetition nanosecond-pulsed CO(2) laser required by EUV LPP sources.
authors.affiliation: Gigaphoton, Inc., 400 Yokokura Shinden, Oyama 323-8558, Japan. kroptics@gmail.com
authors.forename: Krzysztof M
authors.initials: KM
authors.lastname: Nowak
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohta
authors.forename: Takashi
authors.initials: T
authors.lastname: Suganuma
authors.forename: Toshio
authors.initials: T
authors.lastname: Yokotsuka
authors.forename: Junichi
authors.initials: J
authors.lastname: Fujimoto
authors.forename: Hakaru
authors.initials: H
authors.lastname: Mizoguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Endo