Jonah Timothy Hansen


Last Name

Hansen

First Name

Jonah Timothy

ORCID

0000-0003-3992-342X

Organisational unit

09680 - Quanz, Sascha Patrick / Quanz, Sascha Patrick

Filters

2024 - 20258
Reset filters

Search Results

Publications 1 - 8 of 8
  • Astrophotonic Beam Combination in Thin-Film Lithium Niobate
    Item type: Other Conference Item
    Pitz, Oliver; Didier, Pierre; Glauser, Adrian Michael; et al. (2025)
    Science and Technology for the Era of LIFE: Program and Abstracts
  • Beam metrology and control for the Nulling Interferometry Cryogenic Experiment
    Item type: Conference Paper
    Birbacher, Thomas; Glauser, Adrian Michael; Ranganathan, Mohanakrishna; et al. (2024)
    Proceedings of SPIE ~ Optical and Infrared Interferometry and Imaging IX
    We present our progress in stabilising the warm precursor of the Nulling Interferometry Cryogenic Experiment (NICE), a laboratory testbed demonstrating key mid-infrared nulling technologies for the Large Interferometer for Exoplanets (LIFE). To fulfil the preliminary requirements of NICE, the optical path length difference (OPD) between the beams has to be controlled to within 0.8nm RMS, while beam pointing and shear have to be controlled to within ≈1μm and ≈1μrad RMS, respectively. A heterodyne laser metrology system was implemented to monitor OPD and shear in NICE, with pointing measurements following soon. The metrology beams follow the science beams with minimal non-common paths, and modulation techniques enable simultaneous measurements of all critical paths through the testbed at 1kHz analog bandwidth. We use quadrant photodiodes and a small number of components in a compact layout, simplifying future cryogenic or space-based implementations. The noise of the metrology measured in a mock-up is < 0.8nm RMS in OPD, and < 85nm RMS in beam position, with crosstalk between the beams lower than the sensor noise, despite performing multiple measurements on the same detector with overlapping metrology beams. In the warm precursor of NICE, we achieve closed-loop OPD control to within 14nm RMS, which enables an improvement in null depth and stability by a factor of ≈10, reaching a 2 ⋅ 10−4 average null over a two-minute period. The metrology and control systems thus provide both an accurate diagnostic and characterisation tool for NICE, as well as a means to achieve deeper and more stable nulls. The main limitation is a 48Hz vibration from mechanical resonances in the setup, which we will mitigate with an improved mechanical design.
  • The Pyxis Interferometer: Updates and Future Plans
    Item type: Conference Paper
    Hansen, Jonah Timothy; Ireland, Michael J.; Anderson, Olivia; et al. (2024)
    Proceedings of SPIE ~ Optical and Infrared Interferometry and Imaging IX
    In recent years, there has been a renewed interest in technology development for space-based optical and infrared interferometry. One such pathfinder is Pyxis, a set of three autonomous robotic platforms designed to operate in the carpark of Mt Stromlo Observatory, Canberra, where it will simulate formation-flying while performing optical interferometry. In this paper, we will provide an update on the interferometer, detailing the initial results of the control subsystems. We will also share our future plans to begin space qualification and adaptation of Pyxis into a set of nano-satellites.
  • The Nulling Interferometer Cryogenic Experiment - The Warm Phase
    Item type: Conference Paper
    Ranganathan, Mohanakrishna; Birbacher, Thomas; Hansen, Jonah Timothy; et al. (2024)
    Proceedings of SPIE ~ Optical and Infrared Interferometry and Imaging IX
    Context — The Large Interferometer for Exoplanets (LIFE) is a proposed space mission to characterise the atmosphere of terrestrial exoplanets, which is planned to operate in the mid-infrared wavelength region from 6μm to 16μm. A key requirement needed to study the feasibility of this mission is to demonstrate broadband nulling at cryogenic temperatures (15K), at flux levels comparable to the astronomical sources that LIFE will detect. The Nulling Interferometer Cryogenic Experiment (NICE) is a technology demonstrator built to fulfil this purpose. Aim — The objective of NICE is to demonstrate a broadband null with a null depth of 10−5 and stability of 10−8 while maintaining a high system throughput, and consequently a high level of sensitivity, sufficient to detect an Earth twin at 10pc. We describe the optical requirements, the current progress of NICE in the warm phase, and future plans. Methods — NICE is a Single-Bracewell nuller with closed loop optical path-length control, currently operating at ambient conditions. We use a 3.85μm laser with 150nm bandwidth to demonstrate achromatic nulling capability, and a narrowband (< 0.5nm bandwidth) 4.5μm laser to demonstrate stability. Results — We achieve an achromatic null depth of 4.39 · 10−4 with a stability of σ = 5.02 · 10−4 over a duration of 60s without closed loop control, and a stabilised narrow-band null of 2.05 · 10−4 with σ = 9.36 · 10−5 over a duration of 120s. Conclusions — NICE has both demonstrated achromatic operation and closed loop control to stabilise the null. However, the mean null depth and the null stability achieved do not yet meet the requirements, by a factor of 20 and 104 respectively. This will be improved in future iterations.
  • Analytical and Numerical Instrumental Noise Simulations for the Large Interferometer For Exoplanets (LIFE)
    Item type: Conference Paper
    Huber, Philipp A.; Dannert, Felix A.; Laugier, Romain; et al. (2024)
    Proceedings of SPIE ~ Optical and Infrared Interferometry and Imaging IX
    The Large Interferometer For Exoplanets (LIFE) is a proposed space-based mid-infrared nulling interferometer featuring an array of formation-flying collectors and a central beam combiner. Its primary objective is the direct detection of dozens of temperate, terrestrial exoplanets and the investigation of their atmospheres to understand their composition and identify potential biosignatures. To get a realistic performance estimate of LIFE and derive technical requirements, a comprehensive understanding of all major noise sources impacting the mission performance is essential. Previous studies on the performance of LIFE have focused on fundamental noise from astrophysical sources and assumed the impact of instrumental noise to be non-dominant. Here, we report on our ongoing effort to explicitly model instrumental noise for LIFE. We consider two different methods: one providing a numerical solution by explicitly propagating the instability-induced errors in Monte Carlo simulations, and one providing an analytical solution using a second-order approximation of the leakage from instrumental instability noise. We give an overview of the two methods and argue in favor of the numerical method to support the efforts of the LIFE initiative in the ongoing concept phase, due to its flexibility for different observatory architectures, its fidelity in modeling the correlation of errors and fewer limitations concerning the parameter space of potential errors sources.
  • Large Interferometer For Exoplanets (LIFE)
    Item type: Journal Article
    Cesario, Lorenzo; Lichtenberg, Tim; Alei, Eleonora; et al. (2024)
    Astronomy & Astrophysics
    Context: The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization at distances from the Solar System far greater than thermally equilibrated terrestrial exoplanets, offering observational opportunities for unique insights into the origin of secondary atmospheres and the near surface conditions of prebiotic environments. Aims: The Large Interferometer For Exoplanets (LIFE) mission will employ a space-based midinfrared nulling interferometer to directly measure the thermal emission of terrestrial exoplanets. In this work, we seek to assess the capabilities of various instrumental design choices of the LIFE mission concept for the detection of cooling protoplanets with transient high-temperature magma ocean atmospheres at the tail end of planetary accretion. In particular, we investigate the minimum integration times necessary to detect transient magma ocean exoplanets in young stellar associations in the Solar neighborhood. Methods: Using the LIFE mission instrument simulator (LIFEsim), we assessed how specific instrumental parameters and design choices, such as wavelength coverage, aperture diameter, and photon throughput, facilitate or disadvantage the detection of protoplan-ets. We focused on the observational sensitivities of distance to the observed planetary system, protoplanet brightness temperature (using a blackbody assumption), and orbital distance of the potential protoplanets around both G- and M-dwarf stars. Results: Our simulations suggest that LIFE will be able to detect (S/N ≥ 7) hot protoplanets in young stellar associations up to distances of 100 pc from the Solar System for reasonable integration times (up to a few hours). Detection of an Earth-sized protoplanet orbiting a Solar-sized host star at 1 AU requires less than 30 minutes of integration time. M-dwarfs generally need shorter integration times. The contribution from wavelength regions smaller than 6 µm is important for decreasing the detection threshold and discriminating emission temperatures. Conclusions: The LIFE mission is capable of detecting cooling terrestrial protoplanets within minutes to hours in several local young stellar associations hosting potential targets. The anticipated compositional range of magma ocean atmospheres motivates further architectural design studies to characterize the crucial transition from primary to secondary atmospheres.
  • Astrophotonic Beam Combination in Thin-Film Lithium Niobate
    Item type: Conference Poster
    Pitz, Oliver; Jain , Prakhar; Didier, Pierre; et al. (2025)
  • The Large Interferometer For Exoplanets (LIFE): A space mission for mid-infrared nulling interferometry
    Item type: Conference Paper
    Glauser, Adrian Michael; Quanz, Sascha Patrick; Hansen, Jonah Timothy; et al. (2024)
    Proceedings of SPIE ~ Optical and Infrared Interferometry and Imaging IX
    The Large Interferometer For Exoplanets (LIFE) is a proposed space mission that enables the spectral characterization of the thermal emission of exoplanets in the solar neighborhood. The mission is designed to search for global atmospheric biosignatures on dozens of temperate terrestrial exoplanets and it will naturally investigate the diversity of other worlds. Here, we review the status of the mission concept, discuss the key mission parameters, and outline the trade-offs related to the mission's architecture. In preparation for an upcoming concept study, we define a mission baseline based on a free-formation flying constellation of a double Bracewell nulling interferometer that consists of 4 collectors and a central beam-combiner spacecraft. The interferometric baselines are between 10-600 m, and the estimated diameters of the collectors are at least 2 m (but will depend on the total achievable instrument throughput). The spectral required wavelength range is 6-16 mu m (with a goal of 4-18.5 mu m), hence cryogenic temperatures are needed both for the collectors and the beam combiners. One of the key challenges is the required deep, stable, and broad-band nulling performance while maintaining a high system throughput for the planet signal. Among many ongoing or needed technology development activities, the demonstration of the measurement principle under cryogenic conditions is fundamentally important for LIFE.
Publications 1 - 8 of 8