title: A compact, robust, and transportable ultra-stable laser with a fractional frequency instability of 1 × 10(-15.).
abstract: We present a compact and robust transportable ultra-stable laser system with minimum fractional frequency instability of 1 × 10(-15) at integration times between 1 and 10 s. The system was conceived as a prototype of a subsystem of a microwave-optical local oscillator to be used on the satellite mission Space-Time Explorer and QUantum Equivalence Principle Space Test (STE-QUEST) (http://sci.esa.int/ste-quest/). It was therefore designed to be compact, to sustain accelerations occurring during rocket launch, to exhibit low vibration sensitivity, and to reach a low frequency instability. Overall dimensions of the optical system are 40 cm × 20 cm × 30 cm. The acceleration sensitivities of the optical frequency in the three directions were measured to be 1.7 × 10(-11)/g, 8.0 × 10(-11)/g, and 3.9 × 10(-10)/g, and the absolute frequency instability was determined via a three-cornered hat measurement. Two additional cavity-stabilized lasers were used for this purpose, one of which had an instability σy < 4 × 10(-16) at 1 s integration time. The design is also appropriate and useful for terrestrial applications.
authors.affiliation: Institut für Experimentalphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Qun-Feng
authors.initials: QF
authors.lastname: Chen
authors.affiliation: Institut für Experimentalphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Nevsky
authors.affiliation: Institut für Experimentalphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Cardace
authors.affiliation: Institut für Experimentalphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Schiller
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Legero
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Häfner
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Uhde
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Sterr