The ESO Extremely Large Telescope (ELT) has been in construction since 2014. In parallel with the construction of the telescope, ESO has entered into agreements with consortia in the ESO member states to build the first instruments for that telescope. To meet the telescope science goals, the ambitious instrument plan includes two instruments for first light: an optical to near-infrared integral field spectrograph with a dedicated adaptive optics system (HARMONI) and a near-infrared camera with simple spectrograph (MICADO) behind a multi-conjugate adaptive optics module (MAORY). The next instrument will be a mid-infrared imager and spectrograph (METIS). Plans to follow this first suite of instruments include a high-resolution spectrograph (HIRES) and a multi-object spectrograph (MOSAIC). Technology development is underway to prepare for building the ELT Planetary Camera and Spectrograph. An overview of the telescope and its instruments is given.
The Mid-Infrared ELT Imager and Spectrograph (METIS) is one of three first light instruments on the ELT. It will provide high-contrast imaging and medium resolution, slit-spectroscopy from 3 – 19um, as well as high resolution (R ~ 100,000) integral field spectroscopy from 2.9-5.3µm. All modes observe at the diffraction limit of the ELT, by means of adaptive optics, yielding angular resolutions of a few tens of milliarcseconds. The range of METIS science is broad, from Solar System objects to active galactic nuclei (AGN). We will present an update on the main science drivers for METIS: circum-stellar disks and exoplanets. The METIS project is now in full steam, approaching its preliminary design review (PDR) in 2018. In this paper we will present the current status of its optical, mechanical and thermal design as well as operational aspects. We will also discuss the challenges of building an instrument for the ELT, and the required technologies.
In this paper we will report on the status of the instrumentation project for the European Southern Observatory's Extremely Large Telescope (ELT). Three instruments are in the construction phase: HARMONI, MICADO and METIS. The multi-conjugate adaptive optics system for MICADO, MAORY, is also under development. Preliminary Design Reviews of all of these systems are planned to be completed by mid-2019. The construction of a laser tomographic module for HARMONI is part of "Phase 2" of the ELT: the design has been advanced to Preliminary Design level in order to define the interface to the HARMONI spectrograph. Preparations for the next instruments have also been proceeding in parallel with the development of these instruments. Conceptual design studies for the multi-object spectrograph MOSAIC, and for the high resolution spectrograph HIRES have been completed and reviewed. We present the current design of each of these instruments and will summarise the work ongoing at ESO related to their development.
The ELT is a project led by the European Southern Observatory (ESO) for a 40-m class optical, near- and mid-infrared, ground-based telescope. When it will enter into operation, the ESO ELT will be the largest and most powerful optical telescope ever built. It will not only offer unrivalled light collecting power, but also exceedingly sharp images, thanks to its ability to compensate for the adverse effect of atmospheric turbulence on image sharpness. The basic optical solution for the ESO ELT is a folded three-mirror anastigmat, using a 39-m segmented primary mirror (M1), a 4-m convex secondary mirror (M2), and a 4-m concave tertiary mirror (M3), all active. Folding is provided by two additional flat mirrors sending the beams to either Nasmyth foci along the elevation axis of the telescope. The folding arrangement (flat M4 and M5 mirrors) is conceived to provide conveniently located flat surfaces for an adaptive shell (M4) and field stabilization (M5). This paper provides an update of the specifications, design, and manufacturing of the ESO ELT optical systems
A suite of seven instruments and associated AO systems have been planned as the "E-ELT Instrumentation Roadmap". Following the E-ELT project approval in December 2014, rapid progress has been made in organising and signing the agreements for construction with European universities and institutes. Three instruments (HARMONI, MICADO and METIS) and one MCAO module (MAORY) have now been approved for construction. In addition, Phase-A studies have begun for the next two instruments - a multi-object spectrograph and high-resolution spectrograph. Technology development is also ongoing in preparation for the final instrument in the roadmap, the planetary camera and spectrograph. We present a summary of the status and capabilities of this first set of instruments for the E-ELT.
The Atacama Large Millimeter/submillimeter Array (ALMA) will be composed of 66 high precision antennae located at
5000 meters altitude in northern Chile. This paper will present the methodology, tools and processes adopted to system
engineer a project of high technical complexity, by system engineering teams that are remotely located and from
different cultures, and in accordance with a demanding schedule and within tight financial constraints. The technical and
organizational complexity of ALMA requires a disciplined approach to the definition, implementation and verification of
the ALMA requirements. During the development phase, System Engineering chairs all technical reviews and facilitates
the resolution of technical conflicts. We have developed analysis tools to analyze the system performance, incorporating
key parameters that contribute to the ultimate performance, and are modeled using best estimates and/or measured values
obtained during test campaigns. Strict tracking and control of the technical budgets ensures that the different parts of the
system can operate together as a whole within ALMA boundary conditions. System Engineering is responsible for
acceptances of the thousands of hardware items delivered to Chile, and also supports the software acceptance process. In
addition, System Engineering leads the troubleshooting efforts during testing phases of the construction project. Finally,
the team is conducting System level verification and diagnostics activities to assess the overall performance of the
observatory. This paper will also share lessons learned from these system engineering and verification approaches.
The Atacama Large Millimeter and Sub-millimeter Array (ALMA) is a sub-millimeter-wavelength radio telescope under construction in northern Chile at an altitude of 5,000 meters. The ALMA telescope will be composed of 66 to 80 high-precision antennas plus their electronics systems, all of which operate as a single instrument. This telescope will observe the cold regions of the Universe with unprecedented depth and clarity. These regions, which are often optically dark, shine brightly in the sub-millimeter portion of the electromagnetic spectrum. ALMA is a partnership between institutions in Europe, North America, Japan and the Republic of Chile and is currently one of the largest ground-based astronomy projects under construction. ALMA is a complex and technically challenging instrument and the development and construction is dispersed over four continents. Such a project requires a strong system engineering team if it is to come together as a complete system and meet its performance objectives. ALMA System Engineering activities can be divided into; System Design and Analysis, Product Assurance, Prototype System Integration, and System Integration in Chile. This paper reports on these System Engineering activities and achievements. It also describes how the System Engineering team is staffed and organized and reports on some early technical achievements.
The paper presents the general interplay of coarse and fine tracking sub systems for an optical intersatellite link terminal. It briefly describes the hardware items that were designed by the Contraves Space led team to realise the required pointing, acquisition and tracking (PAT) functionality, especially in view of a commercial use of the terminals. Additionally, the control concept is outlined and test results are presented that were obtained during PAT sub system tests, used to verify the acquisition algorithms and the closed loop tracking performance.
The presented paper reports on a conceptual design of a High Precision Optical Metrology (HPOM) system for SMART-2 with the emphasis of establishing and controlling the distance between the satellites. SMART-2 serves as a pre-cursor technology mission for DARWIN where critical technologies will be demonstrated. An overview about the DARWIN and SMART-2 mission and requirements is given. The HPOM system must take over from the Radio Frequency (RF) system at an inferometer arm difference of some cm and must establish and control an arm difference of smaller than 5nm at a 3dB bandwidth of 100Hz. A cascaded metrology system has been developed using different optical metrology methods such as time of flight, dual-wavelength and white light interferometry within one system to meet the ambitious requirement.
Reflections gratings with binary profiles are presented. The binary gratings are composed of a minilattice with feature sizes comparable to the wavelength of the incident light. The overall structure is designed in such a way that it imitates a conventional blazed grating. With the help of the diffraction grating high deflection angles with high diffraction efficiency are possible. The principle of such gratings, both dielectric and metallic gratings, are discussed. Theoretical calculations are shown to be in good agreement with measurements. The limitations on the method, both fundamental and arising due to the manufacturing process, are examined. The generation of a variable phase delay with the help of binary features with sizes close to wavelength, can also be applied to make more complicated optical elements such as Fresnel Zone Lenses and kinoforms.
In this paper we report on the design of diffractive optical elements (DOEs) for high power laser radiation. We modified the Fourier transform algorithm which allows hologram calculation also for reflective type Kinoforms considering the tilted arrangement. To achieve light weighted DOEs which are resistend against intense laser radiation reflective DOEs in silicon were fabricated. The elements have been investigated with respect to the diffraction efficiency and the absorption values.