Dublin City University has successfully tested the laser components of the next generation space navigation atomic clock

The team collaborated with Eblana Photonics and Enlightra to showcase for the first time a new caliber laser, which will enable atomic clocks to be more efficient and compact for future satellite missions.

This innovation addresses the key needs identified by the European Space Agency, which is the leading organization for the next generation of space navigation systems. This work was recently published in the Journal of Optics and Laser Technology.

Professor Liam Barry, the laboratory director, stated that
Without the help of smartphones, many of us find it difficult to navigate new cities or even our own. With the help of satellite navigation systems, these devices can help us find our way with high precision. The same technology supports various applications on our devices, including social media and dating applications.

These navigation systems, such as the Galileo system of the European Union and the global positioning system of the United States, rely on the ultra precise timing ability of microwave atomic clocks, and future optical atomic clocks will have an order of magnitude improvement compared to current microwave transition clocks.

With the rapid improvement of optical clock performance, only when operating in space can they be fully utilized, because on Earth, the clock frequency is influenced by the gravitational potential of the clock's location. Therefore, in the future, most applications that require the highest accuracy will need to operate optical clocks far enough from Earth.

The smaller the error in time measurement during navigation, the smaller the distance error obtained. For example, timing errors of nanoseconds or billionths of a second can be converted into distance and position errors of nearly 30 centimeters. Even the best mechanical and electronic clocks have a few seconds of error per day due to environmental conditions.

By tracking the frequency of electromagnetic radiation when electrons transition from one energy level to another, scientists can pinpoint the time to within a second of billions of years. Therefore, atomic clocks now set the length and time standards of seconds for the world. The current performance of optical clocks far exceeds that of the best microwave clocks, with relative error levels currently below 1 × 10-17. Therefore, it is expected that in the near future, time units will be redefined through optical transitions.

The new aperture laser has been successfully demonstrated for the first time at Dublin City University and will operate in an optical atomic clock using strontium atoms. These atoms are smaller than those used in other clocks and are excited by lasers into energy transitions during a process called optical pumping. The laser developed in this project is smaller than previous iterations and requires less power, which is crucial for the use on satellites.

Space applications impose some of the strictest requirements on atomic clocks used for timing, requiring excellent performance in harsh environments. Perhaps the most critical requirement is the low size, weight, and power (SWaP) requirements compatible with small satellites. The European Space Agency (ESA) is one of the leading forces driving the next generation of space atomic clock technology.

Jim Somers, CEO of Eblana, stated that Eblana Photonics is developing high-performance compact laser diodes with support from the European Space Agency (ESA) and is enthusiastic about adding them to the company's growing catalog of photonic diodes and devices. This innovation started with typical wavelengths in the telecommunications industry, and now exciting new homes have been found at lower wavelengths, which will provide fundamental improvements to the European Space Agency's atomic clock program, "said Richard Phelan, R&D Director of Eblana Photonics.

The Radio and Optical Communication Laboratory at the School of Electronic Engineering at Dublin City University has been dedicated to the development of groundbreaking laser technology for communication and sensing applications for 25 years.

Source: Laser Network