0000000000122981
AUTHOR
Ortwin Hellmig
showing 8 related works from this author
Autonomous frequency stabilization of two extended cavity diode lasers at the potassium wavelength on a sounding rocket
2016
We have developed, assembled, and flight-proven a stable, compact, and autonomous extended cavity diode laser (ECDL) system designed for atomic physics experiments in space. To that end, two micro-integrated ECDLs at 766.7 nm were frequency stabilized during a sounding rocket flight by means of frequency modulation spectroscopy (FMS) of 39^K and offset locking techniques based on the beat note of the two ECDLs. The frequency stabilization as well as additional hard- and software to test hot redundancy mechanisms were implemented as part of a state-machine, which controlled the experiment completely autonomously throughout the entire flight mission.
Space-borne Bose–Einstein condensation for precision interferometry
2018
Space offers virtually unlimited free-fall in gravity. Bose-Einstein condensation (BEC) enables ineffable low kinetic energies corresponding to pico- or even femtokelvins. The combination of both features makes atom interferometers with unprecedented sensitivity for inertial forces possible and opens a new era for quantum gas experiments. On January 23, 2017, we created Bose-Einstein condensates in space on the sounding rocket mission MAIUS-1 and conducted 110 experiments central to matter-wave interferometry. In particular, we have explored laser cooling and trapping in the presence of large accelerations as experienced during launch, and have studied the evolution, manipulation and interf…
Optical frequency combs for space applications
2016
Optical frequency comb-based high resolution laser spectroscopy has been demonstrated in space under micro-gravity on two sounding rocket based experiments. The comb has been used to simultaneously measure two different atomic transitions.
Highly stable Zerodur based optical benches for microgravity applications and other adverse environments
2019
A number of cold atom experiments are restrained by the impeding effects of gravity. While efforts have been made to overcome these limitations in a gravitational environment, another approach is placing the experiment in a microgravity environment, as can be found aboard sounding rockets, satellites or a space station. The cornerstone of such experiments is a robust laser system. The adverse conditions during a rocket launch impose stringent requirements on thermal stability and resilience against mechanical stress on this part of the experimental setup. Furthermore, the very limited space found on any of the aforementioned microgravity platforms necessitates maximal miniaturization. In or…
Space-borne frequency comb metrology
2016
Precision time references in space are of major importance to satellite-based fundamental science, global satellite navigation, earth observation, and satellite formation flying. Here we report on the operation of a compact, rugged, and automated optical frequency comb setup on a sounding rocket in space under microgravity. The experiment compared two clocks, one based on the optical D2 transition in Rb, and another on hyperfine splitting in Cs. This represents the first frequency comb based optical clock operation in space, which is an important milestone for future satellite-based precision metrology. Based on the approach demonstrated here, future space-based precision metrology can be i…
Determining the deformation and resulting coupling efficiency degradation of ultrastable fiber-coupled optical benches under load.
2020
Fiber-coupled optical benches are an integral part of many laser systems. The base of such an optical bench is usually a slab of solid material, onto which optical components are fixed. In many environments, the ability to retain high fiber coupling efficiency under mechanical loads is essential. In this article, we study the fiber-to-fiber coupling efficiency under the application of static mechanical loads experimentally and theoretically: We constructed a simple three-point bending setup to interferometrically measure the deformation of an optical bench under load. Using the same setup, we further recorded the resulting coupling efficiency variations. The examined optical benches are bas…
Highly angular resolving beam separator based on total internal reflection
2019
We present an optical element for the separation of superimposed beams that only differ in angle. The beams are angularly resolved and separated by total internal reflection at an air gap between two prisms. As a showcase application, we demonstrate the separation of superimposed beams of different diffraction orders directly behind acousto-optic modulators for an operating wavelength of 800 nm. The wavelength as well as the component size can easily be adapted to meet the requirements of a wide variety of applications. The presented optical element allows one to reduce the lengths of beam paths and thus to decrease laser system size and complexity.
ZERODUR based optical systems for quantum gas experiments in space
2019
Abstract Numerous quantum technologies make use of a microgravity environment e.g. in space. Operating in this extreme environment makes high demands on the experiment and especially the laser system regarding miniaturization and power consumption as well as mechanical and thermal stability. In our systems, optical modules consisting of ZERODUR® based optical benches with free-space optics are combined with fiber components. Suitability of the technology has been demonstrated in the successful sounding rocket missions FOKUS, KALEXUS and MAIUS-1. Here, we report on our toolkit for stable optical benches including mounts, fixed and adjustable mirrors as well as polarization maintaining fiber …