Hannover 2020 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 22: Posters: Quantum Optics and Photonics II

Q 22.3: Poster

Tuesday, March 10, 2020, 16:30–18:30, Empore Lichthof

Design and Implementation of a Spliced CW-Fiber Amplifier for a Brillouin-LIDAR System — •Benedikt Langfeld, Daniel Koestel, and Thomas Walther — TU Darmstadt, Institut für Angewandte Physik, 64289 Darmstadt

In this work, we present a Brillouin-LIDAR system as an alternative to contact-based measuring techniques for the temperature profiles of the oceanic mixed layer (up to 100 m). This is achieved by exploiting the temperature dependent frequency shift of Brillouin-scattered light.

The LIDAR laser system consists of a cw source followed by a series of cw and pulsed fiber amplifiers. An acousto-optic modulator (AOM) between the cw and pulsed stages is used to form pulses with a duration of 10 ns and flexible repetition rate between 1 kHz and 1 MHz. Finally, the pulses are converted into the green spectral range. To measure the frequency shift of the Brillouin-scattered light, we implemented an adjustable edge filter based on an atomic transition of rubidium [1].

To make the operation of the LIDAR system in a helicopter feasible, the system has to be insensitive to vibrations to prevent misalignment of the laser beam. For this reason the system should be completely fiber based. We present a spliced cw-fiber amplifier in a double pass configuration, whose amplified power is used as the basis for the pulse generation by the AOM.

[1] A. Rudolf and T. Walther, Opt. Lett. 37, 4477-4479 (2012)