Heidelberg 2015 – wissenschaftliches Programm
A 19.1: Vortrag
Mittwoch, 25. März 2015, 11:00–11:15, C/HSO
Compact mode-locked diode laser system for high precision frequency comparison experiments in space — •Heike Christopher1,2, Evgeny Kovalchuk1,2, Andreas Wicht1,2, Götz Erbert2, Günther Tränkle2, and Achim Peters1,2 — 1Institut für Physik, Humboldt-Universität zu Berlin — 2Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik Berlin
We present a compact mode-locked diode laser system designed to generate an optical frequency comb in the wavelength range around 780 nm. It will be used for precision experiments in space which will test the universality of free fall (UFF) by employing light pulse atom interferometry for rubidium and potassium ultra-cold quantum gases.
The passively mode-locked extended-cavity diode laser contains an AlGaAs ridge-waveguide diode chip, collimation aspheric micro-optics, and an external nearly zero group velocity dispersion (GVD) dielectric mirror. Reverse biasing a short section of the two section laser diode enables the passive mode-locking process. Highly stable pulse performance is realized at a repetition rate of about 4 GHz where a free running full-width-at-half-maximum (FWHM) RF linewidth of about 100 Hz (resolution bandwidth 50 Hz) was achieved. We present the current status of our work and discuss options for further improvements, e.g. extending the wavelength range and active stabilization of the repetition rate.
This project is supported by the German Space Agency DLR, with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) under grant numbers 50WM1237-1240.