Optical Technology Applied to Nuclear Fusion

It produces an immense amount of energy, obtained from a virtually inexhaustible source, without the risk of an uncontrolled chain reaction and with minimal, short-lived waste. The future of power generation lies in nuclear fusion, and it is getting closer every day thanks to projects such as the National Ignition Facility (NIF). The world’s largest laser system aims to achieve controlled deuterium-tritium fusion, in order to obtain a new source of clean, safe, and unlimited energy.

This facility includes more than 4,000 optical components, of which Sagittal Optics has selected four as case studies for their adaptation to freeform surfaces. By analyzing them and proposing new designs, it will be possible to demonstrate the need to implement high-quality freeform lenses in this type of optical system. Looking ahead, this new generation of high-quality freeform surfaces could be used in inertial confinement fusion facilities, optimizing their design and producing more compact systems.

Sagittal Optics is a technology partner in the SFOS – Super-polished Freeforms Optical Systems project, an international consortium of leading UK and Swiss companies and universities funded with approximately €3.6 million under the Eureka SMART Manufacturing / Eurostars programme. SFOS is a pioneering initiative to develop nano-scale accurate, ultra-smooth freeform optics that overcome current manufacturing limitations and are critical for advancing laser-fusion systems, a promising path to safe and clean energy without hazardous waste. By contributing to this cutting-edge effort, Sagittal Optics reinforces its commitment to innovation, scientific excellence, and the delivery of next-generation optical solutions that strengthen industrial competitiveness and sustainability on a global scale

The NIF is capable of concentrating, into a diameter the size of a pencil eraser, the light beam generated by the 192 lasers that make up the system, which covers an area equivalent to three football fields and rises ten stories high. This immense surface is currently essential for the light to undergo the amplification, transport, and focusing required to achieve the goal of fusion. At the point where the fusion reaction occurs, the concentration of energy generates temperatures even higher than those at the core of the Sun.

Freeform lenses, such as those being designed at Sagittal Optics, represent a frontier in optomechanical design and have only very recently begun to be used. These lenses offer several advantages over traditional spherical lenses, which were already employed by Galileo and Newton in their telescopes. They also surpass aspherical lenses, which have gained prominence in recent years by improving image quality and correcting aberrations more effectively than their spherical counterparts. Freeform lenses are particularly useful in addressing the gravitational and thermal loads associated with large-scale systems and extremely high temperatures, such as those reached at NIF. However, their design and manufacture present a true challenge, making research efforts like those carried out by Sagittal Optics essential for achieving the best results.

Since the 1960s, when the potential of laser technology and its diverse laser applications in this type of experiment was first explored, decades of research and technological development have been devoted to achieving controlled fusion at laboratory scale. Thanks to ongoing scientific progress, we are now closer than ever to providing future generations with a clean, safe, and virtually inexhaustible energy alternative.