The Extremely Large Telecope (ELT) is expected to begin scientific operations in 2030, with MICADO as its first-light imager. The Single Conjugate Adaptive Optics (SCAO) system for MICADO is currently being assembled and tested at the Observatoire de Paris. MICADO's baseline AO control strategy uses a hybrid approach: a Linear Quadratic Gaussian (LQG) regulator for low-order modes, optimised to adapt to the disturbance caused by vibrations and ELT windshake, and an integral action controller for higher-oder modes. Despite the non linearity of the Pyramid Wavefront Sensor (PyWFS), the so-called "optical gains", LQG control has proven to be highly effective in simulation. It has been shown that the LQG regulator is resilient to optical gain variations in the loop or to inaccuracies in their estimation. Increasing the number of modes controlled by the LQG regulator would therefore make the controller less sensitive to the optical gains, which are notoriously difficult to estimate during operation. A first hybrid controller, with only tip-tilt controlled with LQG control, has been validated using COMPASS, the end-to-end, GPU-accelerated, AO simulation platform. We will present the first experimental validation of this hybrid controller on the MICADO-SCAO bench. We will also present results obtained by increasing the number of modes controlled with LQG control and the work carried out to go towards an autonomous LQG regulator.

The SAXO+ upgrade of the VLT/SPHERE adaptive optics system introduces a second-stage near-infrared pyramid wavefront sensor to improve high-contrast imaging, making accurate calibration of non-common path aberrations (NCPAs) essential to fully exploit its performance. This work refines the expected level of NCPAs in SAXO+ and presents the calibration procedures developed for static NCPA compensation and focal-plane dark-hole control. Monte Carlo simulations based on an updated Zemax optical model were used to estimate the NCPA error budget. These simulations are in good agreement with previous measurements on SPHERE and with the assumptions adopted in earlier performance studies. We also propose a calibration strategy that offloads most static aberration correction to the first-stage deformable mirror while preserving the second-stage mirror stroke for high-speed adaptive optics correction. These results validate the expected SAXO+ optical quality and establish the calibration framework required for efficient NCPA compensation and focal-plane wavefront control during future on-sky operations.

MICADO is the designated ELT first light instrument, a near-infrared imager working at the diffraction limit of the telescope thanks to a SCAO and an MCAO mode. Since summer 2024, MICADO is in its AIT phase and all MICADO partners are currently integrating their subsystems. The MICADO SCAO module will follow three successive AIT phases in France: the beta flat configuration, the flat configuration and the final configuration. In this contribution I will first present the progress made in the AIT of the beta flat configuration and its closed loop results. I will then present the performed and on-going tasks for the flat and final configurations (manufacturing, delivery and integration of several SCAO subsystems and pieces of software) and the results obtained so far in the flat configuration. I will then conclude with the expected following steps of the SCAO module AIT in Garching.

The emphasis on throughput in GPU design poses challenges when integrating them into time-sensitive applications. Recent advancements in GPU architectures and software have enabled the reduction of overhead and interference along the critical path through the use of advanced GPU mechanisms, such as persistent kernels. Despite these advancements, these methods often involve trade-offs in performance, flexibility, or portability. In response, we introduce our proposal of persistent graphs to enable a fully host-independent GPU pipeline scheduler. This concept is entirely modular, simple to implement and allows for online changes of workloads without impacting performance. We demonstrate the effectiveness of our approach through extensive benchmarking including an example of a highly constrained cyber-physical system: adaptive optics for astronomy. Our evaluation spans various state-of-the-art platforms, including A100 GPUs and embedded Jetson Orin SoCs. Notably, with our proposed implementation, response time variability never exceeds 10%, even on platform with significant CPU interference.

In order to address new science objectives in exoplanet imaging, the SAXO+ technical development project has been undertaken for the SPHERE instrument at ESO's VLT. As a part of this, the AO system will be completed by adding a second, faster stage of correction. We present simulation results obtained by implementing an optimal predictive linear quadratic Gaussian controller for the 2nd stage. The prediction relies on a stochastic state-space disturbance model fully identified from closed-loop measurements. In addition, we also investigate a disentangled cascade AO (dCAO) mode where the model represents the full incoming disturbance and is identified using in addition the 1st stage commands.

SAXO+ is a second-stage adaptive optics module for the SPHERE instrument at VLT. It has been proposed to increase the achievable contrast and improve the current performance of detecting and characterizing exoplanets and disks. It is developed by the SPHERE+ consortium as part of the roadmap activity for the planet finder instrument (PCS) of the Extremely Large Telescope (ELT). This paper describes the optical and mechanical design of SAXO+.

The COSMIC platform endeavors to establish a potent, versatile, and accessible AO RTC platform for the AO community. This joint project allies the Observatoire de Paris with the Australian National University (ANU), and relies on the CACAO software, a creation of the Subaru Telescope. Although the primary intended use was for the ELT AO instrument, the platform now accommodates several systems on different scales. The effectiveness of COSMIC in current and future AO systems has already been proven. The current progress on the COSMIC platform extends beyond, with technical solutions offered for various applications other than AO such as embedded systems, radio astronomy, and radar. This interest exhibited by other communities has initiated new collaborations and additions to the platform, which might appeal to the AO community. This paper presents the current state of the COSMIC platform, including ongoing developments and future perspectives. One recent development is heterogeneous computation which allows for a hardware-agnostic real-time pipeline, thereby enabling the deployment of an AO pipeline on both CPU and GPU, irrespective of the vendor (NVIDIA or AMD). Another contribution involves the porting of COSMIC onto an NVIDIA Jetson Xavier, effectively paving the way for embedded system applications. As artificial intelligence is rapidly gaining importance in the AO community, efforts have been made to incorporate machine learning inference into the real-time critical path. Additionally, a collaboration with the radio astronomy community has led to a significant contribution towards efficient real-time data ingestion at a high volume. This paper aims to illustrate these achievements and demonstrate their potential applications within the AO community.

SPHERE, operating at the VLT since 2014, is currently one of the high-contrast instruments with a higher performance. Its adaptive optics system, known as SAXO, will be upgraded to SAXO+, which features the addition of a second stage of adaptive optics. This stage will use a near-infrared pyramid wavefront sensor to record images of fainter exoplanets around redder stars. In this work, we compare the performance of SAXO and SAXO+. We look for the optimal values of the key system parameters of SAXO+ for various science cases and turbulence conditions. We performed numerical simulations using COMPASS, an end-to-end adaptive optics simulation tool. We simulated perfect coronagraph images of an on-axis point source, and we minimized the residual starlight intensity between 3 and $5\ / D$ as a performance criterion. The explored parameter space includes science cases (described by magnitude in G and J bands), turbulence conditions (seeing and coherence time), and key system parameters (first and second stage gains, first and second stage frequencies, pyramid modulation radius, pyramid modal gains optimization). In every science case and turbulence condition, SAXO+ reduces the residual starlight intensity inside the correction zone of the second stage by a factor of ten compared to SAXO. The optimal first stage gain is lower for SAXO+ than for SAXO alone. We quantified the gain in performance of SAXO+ when changing the second stage frequency from 2\,kHz to 3\,kHz, and we conclude that 2\,kHz may be sufficient for most realistic conditions. We give the optimal first stage gain as well as the first and second stage frequencies for every seeing, coherence time, and science case. Finally, we find that a $2\ WFS / D$ pyramid modulation radius is a good trade-off between performance and robustness against varying turbulence conditions. This study shows that the future SAXO+ system will outperform the current SAXO system in all studied cases.

MICADO is the ELT first light instrument, an imager working at the diffraction limit of the telescope thanks to two adaptive optics (AO) modes: a single conjugate one (SCAO), available at the instrument first light and developed by the MICADO consortium, and a multi conjugate one (MCAO), developed by the MORFEO consortium. Although the project final design review process is about to be completed, the review board and ESO acknowledged that "the review of the final design can be considered complete for the majority of the MICADO sub-systems" and agreed that MICADO can start manufacturing. For the MICADO SCAO module, we have started the manufacturing of several parts: the majority of the SCAO optics and of the SCAO mechanics, the real-time computer software and the instrument control software. This manufacturing is ordered in several steps to allow the progressive integration of a first full AO close loop with the final SCAO parts. In this contribution, we will focus on the first two steps: on our AO Sesame bench and the so-called "beta flat configuration". We will present the status of this manufacturing and the first results obtained.

MICADO is a first light instrument for the Extremely Large Telescope (ELT), set to start operating later this decade. It will provide diffraction limited imaging, astrometry, high contrast imaging, and long slit spectroscopy at near-infrared wavelengths. During the initial phase operations, adaptive optics (AO) correction will be provided by its own natural guide star wavefront sensor. In its final configuration, that AO system will be retained and complemented by the laser guide star multi-conjugate adaptive optics module MORFEO (formerly known as MAORY). Among many other things, MICADO will study exoplanets, distant galaxies and stars, and investigate black holes, such as Sagittarius A* at the centre of the Milky Way. After their final design phase, most components of MICADO have moved on to the manufacturing and assembly phase. Here we summarize the final design of the instrument and provide an overview about its current manufacturing status and the timeline. Some lessons learned from the final design review process will be presented in order to help future instrumentation projects to cope with the challenges arising from the substantial differences between projects for 8-10m class telescopes (e.g. ESO-VLT) and the next generation Extremely Large Telescopes (e.g. ESO-ELT). Finally, the expected performance will be discussed in the context of the current landscape of astronomical observatories and instruments. For instance, MICADO will have similar sensitivity as the James Webb Space Telescope (JWST), but with six times the spatial resolution.

This study introduces a novel frequency-based data-driven controller for adaptive optics, using power spectral density for optimization while ensuring stability criteria. It addresses disturbance rejection, command amplitude constraints and system transfer functions through convex optimization to obtain an optimal control in an infinite input response filter form. Evaluated within the SAXO+ project, it demonstrates efficacy under diverse atmospheric conditions and operational scenarios. The proposed controller is tested in both standard and disentangled adaptive optics schemes, showcasing its adaptability and performance. Experimental validation is conducted using the COMPASS simulation tool, affirming the controller's promise for enhancing adaptive optics systems in real-world applications.

The Spectro-Polarimetric High-contrast Exoplanet REsearch instrument has now been in operation at the VLT for more than 5 years, demonstrating a high level of performance. SPHERE has produced outstanding results using a variety of operating modes, primarily in the field of direct imaging of exoplanetary systems, focusing on exoplanets as point sources and circumstellar disks as extended objects. The achievements obtained thus far with SPHERE have motivated a large consortium to propose an upgrade: the SPHERE+ project capitalizes on the expertise and lessons learned from SPHERE to push high contrast imaging performance to its limits on the VLT 8m-telescope. The proposed upgrade takes the form of a high-speed adaptive optics second stage, SAXO+, including a deformable mirror, a pyramid wavefront sensor, and a Real-Time Controller (RTC). Paving the way toward PCS, SAXO+ can be seen as a technical demonstrator for advanced AO control strategies, with a fast-track development aiming at the first light in 2027. In this context, the RTC is a core component that must be flexible enough to handle various control strategies, including AI, while ensuring high efficiency to be able to control the AO loop at high framerate. To achieve those goals, COSMIC has been selected to provide the required hard real-time capabilities, supplemented by the ESO RTC Toolkit for the implementation of soft real-time clustering. This paper will focus on the SAXO+ RTC preliminary design, including the main features of the RTC and preliminary benchmark results.

We present results on integrating machine learning (ML) methods for adaptive optics control with a real-time control library: COmmon Scalable and Modular Infrastructure for real-time Control (COSMIC). We test the integration on simulations for the instrument SAXO+. Our proposed solution's pipeline is formed by a two-model ML system. The first model consists of a very deep neural network (DNN) that maps wavefront sensor (WFS) images to phase and is trained offline. The second model consists of predictive control with a more compact DNN. The predictive control stage is trained online, providing an adaptive solution to changing atmospheric conditions but adding extra complexity to the pipeline. On top of implementing the solution with COSMIC, we add a set of modifications to provide faster inference and online training. Specifically, we test NVIDIA's TensorRT to accelerate the DNNs inference, reduced precision, and just-in-time compilation for PyTorch. We show real-time capabilities by using COSMIC and improved speeds both in inference and training by using the recommendations mentioned above.

SAXO+ is a planned enhancement of the existing SAXO, the VLT/ SPHERE adaptive optics system, deployed on ESO's Very Large Telescope. This upgrade is designed to significantly enhance the instrument's capacity to detect and analyze young Jupiter-like planets. The pivotal addition in SAXO+ is a second-stage adaptive optics system featuring a dedicated near-infrared pyramid wavefront sensor and a second deformable mirror. This secondary stage is strategically integrated to address any residual wavefront errors persisting after the initial correction performed by the current primary AO loop, SAXO. However, several recent studies clearly showed that in good conditions, even in the current system SAXO, non-common path aberrations (NCPAs) are the limiting factor of the final normalized intensity in focal plane, which is the final metric for ground-based high-contrast instruments. This is likely to be even more so the case with the new AO system, with which the AO residuals will be minimized. Several techniques have already been extensively tested on SPHERE in internal source and/or on-sky and will be presented in this paper. However, the use of a new type of sensor for the second stage, a pyramid wavefront sensor, will likely complicate the correction of these aberrations. Using an end-to-end AO simulation tool, we conducted simulations to gauge the effect of measured SPHERE NCPAs in the coronagraphic image on the second loop system and their correction using focal plane wavefront sensing systems. We finally analyzed how the chosen position of SAXO+ in the beam will impact the evolution of the NCPAs in the new instrument.