Related papers: Fast modulation and dithering for the NFIRAOS Pyra…

Multi-photon microscopy is a powerful technique for deep-tissue imaging, providing high spatial resolution at increased penetration depth. Nevertheless, imaging remains largely restricted to superficial tissue layers well below 1 mm.…

In the last few years the concept of an active space telescope has been greatly developed, to meet demanding requirements with a substantial reduction of tolerances, risks and costs. This is the frame of the LATT project (an ESA TRP) and…

The MagAO-X instrument is an upgrade of the Magellan AO system that will introduce extreme adaptive optics capabilities for high-contrast imaging at visible and near-infrared wavelengths. A central component of this system is a…

The calibration of future wide field adaptive optics (WFAO) systems requires knowledge of the geometry of the system, in particular the alignment parameters between the sub-apertures of the wavefront sensors (WFS), pupil and deformable…

The next generation of Extremely Large Telescope (24 to 39m diameter) will suffer from the so-called "pupil fragmentation" problem. Due to their pupil shape complexity (segmentation, large spiders ...), some differential pistons may appear…

We observed Proxima Centauri with the Spitzer Space Telescope InfraRed Array Camera (IRAC) five times in 2016 and 2017 to search for transits of Proxima Centauri b. Following standard analysis procedures, we found three asymmetric,…

The Large Synoptic Survey Telescope (LSST) will use an active optics system (AOS) to maintain alignment and surface figure on its three large mirrors. Corrective actions fed to the LSST AOS are determined from information derived from 4…

Dedicated spectrometers for terahertz radiation with [0.3, 30] THz frequencies using traditional optomechanical interferometry are substantially less common than their infrared and microwave counterparts. This paper presents the design and…

The upcoming extremely large telescopes will have to deal with the so-called ''pupil fragmentation'' effect: for what concerns the Extremely Large Telescope (ELT), the presence of thick spider legs supporting the secondary mirror may induce…

Context: Ground-based telescopes are susceptible to seeing, an atmospheric phenomenon that reduces the resolving power of large observatories to that of a home telescope. Compensating these effects is therefore critical to realizing the…

We present a novel way of wavefront sensing using a commercially available, continuous-wave time-of-flight camera with QVGA-resolution. This CMOS phase camera is capable of sensing externally modulated light sources with frequencies up to…

We present a promising approach to the extremely fast sensing and correction of small wavefront errors in adaptive optics systems. As our algorithm's computational complexity is roughly proportional to the number of actuators, it is…

Astronomers working with faint targets will benefit greatly from improved image quality on current and planned ground-based telescopes. At present, most adaptive optic systems are targeted at the highest resolution with bright guide stars.…

The pyramid wavefront sensor (PyWFS) has become increasingly popular to use in adaptive optics (AO) systems due to its high sensitivity. The main drawback of the PyWFS is that it is inherently nonlinear, which means that classic linear…

The LISA Pathfinder mission to space employs an optical metrology system (OMS) at its core to measure the distance and attitude between two freely floating test-masses to picometer and nanorad accuracy, respectively, within the measurement…

We present a new type of tunable mirror with sharply-featured freeform displacement profiles, large displacements of several 100\mu m and high operating frequencies close to the kHz range at 15mm diameter. The actuation principle is based…

A new wavefront sensing approach, derived from the successful curvature wavefront sensing concept but using a non-linear phase retrieval wavefront reconstruction scheme, is described. The non-linear curvature wavefront sensor (nlCWFS)…

The National Ignition Facility (NIF) requires that pulses from each of the 192 laser beams be positioned on target with an accuracy of 50 um rms. Beam quality must be sufficient to focus a total of 1.8 MJ of 0.351-um light into a…

The Total Internal Reflection Ultrasonic Sensor (TIRUS) is a device especially aimed at detecting subsurface flaws in a tested specimen based on the frustrated total internal reflection of bulk ultrasonic waves in the sensor body [1]. In…

Full sky coverage Adaptive Optics on Extremely Large Telescopes requires the adoption of several Laser Guide Stars as references.With such large apertures, the apparent elongation of the beacons is absolutely significant.With few…