Nanosatellites for quantum science and technology

Bringing quantum science and technology to the space frontier offers exciting prospects for both fundamental physics and applications such as long-range secure communication and space-borne quantum probes for inertial sensing with enhanced accuracy and sensitivity. But despite important terrestrial pathfinding precursors on common microgravity platforms and promising proposals to exploit the significant advantages of space quantum missions, large-scale quantum testbeds in space are yet to be realized due to the high costs and leadtimes of traditional “Big Space” satellite development. But the “small space” revolution, spearheaded by the rise of nanosatellites such as CubeSats, is an opportunity to greatly accelerate the progress of quantum space missions by providing easy and affordable access to space and encouraging agile development. We review space quantum science and technology, CubeSats and their rapidly developing capabilities, and how they can be used to advance quantum satellite systems

First stellar photons for an integrated optics discrete beam combiner at the William Herschel Telescope

We present the first on-sky results of a four-telescope integrated optics discrete beam combiner (DBC) tested at the 4.2mWilliamHerschel Telescope. The device consists of a four-input pupil remapper followed by a DBC and a 23-output reformatter. The whole device was written monolithically in a single alumino-borosilicate substrate using ultrafast laser inscription. The device was operated at astronomical H-band (1.6 μm), and a deformable mirror along with a microlens array was used to inject stellar photons into the device. We report the measured visibility amplitudes and closure phases obtained on Vega and Altair that are retrieved using the calibrated transfer matrix of the device. While the coherence function can be reconstructed, the on-sky results show significant dispersion from the expected values. Based on the analysis of comparable simulations, we find that such dispersion is largely caused by the limited signal-to-noise ratio of our observations. This constitutes a first step toward an improved validation of theDBCas a possible beam combination scheme for long-baseline interferometry. © 2021 Optical Society of America

Space-borne Bose-Einstein condensation for precision interferometry

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 interferometry employing Bragg scattering of BECs during the six-minute space flight. In this letter, we focus on the phase transition and the collective dynamics of BECs, whose impact is magnified by the extended free-fall time. Our experiments demonstrate a high reproducibility of the manipulation of BECs on the atom chip reflecting the exquisite control features and the robustness of our experiment. These properties are crucial to novel protocols for creating quantum matter with designed collective excitations at the lowest kinetic energy scales close to femtokelvins.Comment: 6 pages, 4 figure

Astrophotonics: Processing starlight

The field of astrophotonics has been fostering photonic innovations critical and unique to astronomical applications for several years. As we are about to embark on the new era of extremely large telescopes, astrophotonics is poised to become an integral part of the next generation astronomical instruments

Astrophotonics:Introduction to the feature issue

Astrophotonics is an emerging field that focuses on the development of photonic components for astronomical instrumentation. With ongoing advancements, astrophotonic solutions are already becoming an integral part of existing instruments. A recent example is the (sic)60M ESO GRAVITY instrument at the Very Large Telescope Interferometer, Chile, that makes heavy use of photonic components. We envisage far-reaching applications in future astronomical instruments, especially those intended for the new generation of extremely large telescopes and in space. With continued improvements in extreme adaptive optics, the case becomes increasingly compelling. The joint issue of JOSA B and Applied Optics features more than 20 state-of-the-art papers in diverse areas of astrophotonics. This introduction provides a summary of the papers that cover several important topics, such as photonic lanterns, beam combiners and interferometry, spectrographs, OHsuppression, and coronagraphy. (C) 2021 Optical Society of Americ

Astrophotonics:introduction to the feature issue

Astrophotonics is an emerging field that focuses on the development of photonic components for astronomical instrumentation. With ongoing advancements, astrophotonic solutions are already becoming an integral part of existing instruments. A recent example is the (sic)60M ESO GRAVITY instrument at the Very Large Telescope Interferometer, Chile, that makes heavy use of photonic components. We envisage far-reaching applications in future astronomical instruments, especially those intended for the new generation of extremely large telescopes and in space. With continued improvements in extreme adaptive optics, the case becomes increasingly compelling. The joint issue of JOSA B and Applied Optics features more than 20 state-of-the-art papers in diverse areas of astrophotonics. This introduction provides a summary of the papers that cover several important topics, such as photonic lanterns, beam combiners and interferometry, spectrographs, OH suppression, and coronagraphy. (C) 2021 Optical Society of Americ

Fiber-connectorized ultrafast-laser-inscribed K-band integrated optics beam combiner for the CHARA telescope array

A fiber-connectorized K-band integrated-optics two-telescope beam combiner was developed for long-baseline interferometry at the CHARA telescope array utilizing the ultrafast laser inscription (ULI) technique. Single-mode waveguide insertion losses were measured to be ∼1.1 dB over the 2–2.3 µm window. The development of asymmetric directional couplers enabled the construction of a beam combiner that includes a 50:50 coupler for interferometric combination and two ∼75 : 25 couplers for photometric calibration. The visibility of the bare beam combiner was measured at 87% and then at 82% after fiber-connectorization by optimizing the input polarization. These results indicate that ULI technique can fabricate efficient fiber-connectorized K-band beam combiners for astronomical purposes.</p

Ultrafast laser inscription of asymmetric integrated waveguide 3 dB couplers for astronomical K-band interferometry at the CHARA array

We present the fabrication and characterization of 3 dB asymmetric directional couplers for the astronomical K-band at wavelengths between 2.0 and 2.4 mu m. The couplers were fabricated in commercial Infrasil silica glass using an ultrafast laser operating at 1030 nm. After optimizing the fabrication parameters, the insertion losses of straight single-mode waveguides were measured to be similar to 1.2 +/- 0.5 dB across the full K-band. We investigate the development of asymmetric 3 dB directional couplers by varying the coupler interaction lengths and by varying the width of one of the waveguide cores to detune the propagation constants of the coupled modes. In this manner, we demonstrate that ultrafast laser inscription is capable of fabricating asymmetric 3 dB directional couplers for future applications in K-band stellar interferometry. Finally, we demonstrate that our couplers exhibit an interferometric fringe contrast of >90%. This technology paves the path for the development of a two-telescope K-band integrated optic beam combiner for interferometry to replace the existing beam combiner (MONA) in Jouvence of the Fiber Linked Unit for Recombination (JouFLU) at the Center forHigh Angular Resolution Astronomy (CHARA) telescope array. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License