Brimrose Fiber Coupled AO Modulator now on INTERNATIONALSPACE STATION

12 Mar 2025

Sparks, MD -  An Acousto-Optic Modulator (AOM) made by the Brimrose Corporation of America is now being implemented by NASA as part of a new facility known as the Cold Atom Laboratory (CAL) on the International Space Station (ISS).  We are delighted that our acousto-optic modulator was selected by NASA for this important mission.  It is another example of how we customize our A-O devices for various applications so that they can be used throughout the world and on into space.

The Cold Atom Laboratory was developed at NASA’s Jet Propulsion Laboratory and already has begun operating on the ISS. It will provide scientists with an improved set of tools for probing the realm of quantum mechanics, which is the study of nature at the very smallest scale.

The Fiber Coupled AOM is considered to be the key component inside CAL for manipulating the atoms for interferometry, according to James Kellogg, CAL Engineer of Lasers and Optics at the Jet Propulsion Lab.  It is a solid-state device that can tune laser light to very specific frequencies while switching “ON” and “OFF” in less than 100 nanoseconds.  

The CAL facility will produce clouds of ultra-cooled atoms called Bose-Einstein Condensates (BEC). These are chilled to a fraction of a degree above absolute zero, or even colder than the average temperature of deep space. The atoms in a BEC demonstrate quantum characteristics at relatively large-size scales, allowing researchers to explore this strange domain with greater understanding.

To reach these ultra-cold temperatures, the CAL uses a three-step process. First, lasers are used to corral the atoms and slow them down, stealing their energy and reducing the temperature to approximately 100 microKelvin. This step is completed with a device called a magneto-optical trap. The cooled atoms are then help in a “magnetic trap” that causes the warmest atoms in the cloud to separate from the cooler atoms; radio waves then push the warm atoms away, reducing the cloud’s overall temperature to less than 1 microKelvin. Thirdly, the cloud’s natural expansion causes the temperature to drop further (this is called adiabatic expansion) into the 100 picoKelvin range.

In one year, the CAL instrument is expected to be fitted by astronauts with a new atom trapping cell that is currently being designed to deliver the AOM light pulses to the atoms.

Brimrose have been designing custom A-O Modulators for more than 35 years. The A-O modulators are used to control laser beam intensity, frequency modulation, frequency shifting, to control pulses and more.  Brimrose AOMs are offered from the ultraviolet to LWIR wavelength ranges for low and high optical power operation. These cover frequency ranges from just a few MHz up to 3.5 GHz.

For more information, contact Jan S. Kasprzak at jank@brimrose.com or call 410-472-7070.