By T. Jayani, JadeTimes News
High in Chile's arid Atacama Desert, the European Space Observatory (ESO) is constructing the world's largest optical telescope, aptly named the Extremely Large Telescope (ELT). While the name may be straightforward, the engineering behind "the world’s biggest eye on the sky" is anything but simple. Set to begin capturing images in 2028, the ELT is expected to significantly advance our understanding of the universe. Central to this mission are some of the most sophisticated mirrors ever created.
Dr. Elise Vernet, an adaptive optics expert at ESO, has been leading the development of the five massive mirrors that will channel light to the telescope’s instruments. Each mirror is a marvel of optical engineering, with the 14 foot convex M2 mirror being described by Dr. Vernet as "a piece of art." However, it is the M1 and M4 mirrors that truly highlight the precision and complexity involved.
The M1 mirror, the largest ever made for an optical telescope, is composed of 798 hexagonal segments aligned to function as a single, flawless 39 meter (128-foot) mirror. It will collect 100 million times more light than the human eye and must maintain an accuracy 10,000 times finer than the width of a human hair. The M4 mirror, the largest deformable mirror ever built, can adjust its shape 1,000 times per second to correct for atmospheric distortions and vibrations in the telescope, ensuring sharp, clear images. The mirror's flexible surface consists of six ultra thin glass ceramic petals, manufactured in Germany and polished to perfection in France.
As these colossal mirrors prepare for their journey to Chile, scientists at the Max Planck Institute for Quantum Optics in Garching, near ESO’s headquarters, are working on a vastly different scale. In 2020, researchers succeeded in aligning 200 atoms to create a quantum mirror capable of reflecting light a mirror so small it’s invisible to the naked eye. In 2023, they advanced this technology by placing a single atom at the center of the array, turning the system into a "quantum switch" that can control whether the atoms are reflective or transparent. This breakthrough has potential applications in quantum technologies, including secure quantum communication networks.
Meanwhile, in Oberkochen near Stuttgart, Zeiss is producing mirrors with unparalleled precision for extreme ultraviolet lithography (EUV) machines, which are crucial for printing computer chips. These ultra flat mirrors, developed over years, are key components in machines made by Dutch company ASML, the world leader in EUV technology. Zeiss's mirrors can reflect light at extremely small wavelengths, allowing for the creation of chips with increasingly dense transistor arrays. Dr. Frank Rohmund, president of semiconductor manufacturing optics at Zeiss, explains that if a household mirror were enlarged to the size of Germany, its highest peak would be five meters; for an EUV mirror, this peak would be just 0.1 millimeters.
Zeiss continues to innovate, aiming to enable the production of microchips with one trillion transistors by 2030 a significant leap from the hundred billion possible today. This advance, driven by cutting edge mirror technology, is expected to further revolutionize fields like artificial intelligence.
As humanity pushes the boundaries of technology and science, mirrors will undoubtedly remain central to our progress, helping us see further and achieve more than ever before.
