Compact and robust diode laser system technology for dual-species ultracold atom experiments with rubidium and potassium in microgravity.

We present a compact and robust distributed-feedback diode laser system architecture for ultracold atom experiments with 41 and 87 in a mobile setup operating at the ZARM drop tower in Bremen. Our system withstands DC accelerations of up to 43 g in operation with only minor adjustments over several drop campaigns. Micro-integrated master-oscillator-power-amplifier modules in conjunction with miniaturized, free-space opto-mechanics are integrated on a platform with a volume of 43 L.

Method for in-depth characterization of electro-optic phase modulators.

A flexible method to measure the modulation efficiency and residual amplitude modulation, including non-linearities, of phase modulators is presented. The method is based on demodulation of the modulated optical field in the optical domain by means of a heterodyne interferometer and subsequent analysis of the I&Q quadrature components of the corresponding RF beat note signal. As an example, we determine the phase modulation efficiency and residual amplitude modulation for both the TE and TM modes of a GaAs chip-based phase modulator at the wavelength of 1064 nm.

High-power, micro-integrated diode laser modules at 767 and 780 nm for portable quantum gas experiments.

We present micro-integrated diode laser modules operating at wavelengths of 767 and 780 nm for cold quantum gas experiments on potassium and rubidium. The master-oscillator-power-amplifier concept provides both narrow linewidth emission and high optical output power. With a linewidth (10 μs) below 1 MHz and an output power of up to 3 W, these modules are specifically suited for quantum optics experiments and feature the robustness required for operation at a drop tower or on-board a sounding rocket.

Accurate frequency noise measurement of free-running lasers.

We present a simple method to accurately measure the frequency noise power spectrum of lasers. It relies on creating the beat note between two lasers, capturing the corresponding signal in the time domain, and appropriately postprocessing the data to derive the frequency noise power spectrum. In contrast to methods already established, it does not require stabilization of the laser to an optical reference, i.

Micro-integrated extended cavity diode lasers for precision potassium spectroscopy in space.

We present a micro-integrated, extended cavity diode laser module for space-based experiments on potassium Bose-Einstein condensates and atom interferometry. The module emits at the wavelength of the potassium D2-line at 766.7 nm and provides 27.

Micro-integrated 1 Watt semiconductor laser system with a linewidth of 3.6 kHz.

We demonstrate a compact, narrow-linewidth, high-power, micro-integrated semiconductor-based master oscillator power amplifier laser module which is implemented on a footprint of 50 x 10 mm(2). A micro-isolator between the oscillator and the amplifier suppresses optical feedback. The oscillator is a distributed Bragg reflector laser optimized for narrow-linewidth operation and the amplifier consists of a ridge waveguide entry and a tapered amplifier section.

Thermoacoustic optical path length stabilization in a single-mode optical fiber.

We present a simple technique to actively stabilize the optical path length in an optical fiber. A part of the fiber is coated with a thin, electrically conductive layer, which acts as a heater. The optical path length is thus modified by temperature-dependent changes in the refractive index and the mechanical length of the fiber.