New Nitrogen-Argon Open-Air Laser Study Could Change the Laser Community

A team of researchers from the University of California Los Angeles (UCLA) and the Max Born Institute published a study demonstrating the use of Nitrogen and Argon to create laser light.

A team of researchers from the University of California Los Angeles (UCLA) and the Max Born Institute have published a study demonstrating the use of Nitrogen and Argon to create laser light. The study builds on decades of research into the field of creating open-air lasers, which could one day help to improve sensors, robotics, and much more.

Here's what you need to know.

Laser Tech

For decades, the primary way lasers operated was by shooting a beam of light through an optical cavity at a pair of mirrors. These mirrors are constructed and angled in a manner that enables the light to be bounced back and forth between the devices. This bouncing action amplifies the intensity of that light, creating the focused beam you see.

Open-Air Lasers

Since the beginning of laser research, there have been engineers seeking to create laser light without the use of amplification cavities and mirrors. Within this research, there is a subsection of engineers who seek to create open-air lasers. These devices utilize interactions between particles excited by intense light to form laser light. Until recently, this scientific concept was not possible. However, it appears that the tides have changed following the publication of this recent study.

Nitrogen Argon Open-Air Laser Study

The study delves into using Nitrogen and Argon mixtures to induce cavity-free lasing in atmospheric air. The study, published in Physical Review Letters, introduces the concept and a working model that accomplished photon-mediated energy transference between N2 and Ar, resulting in a superfluorescence response.

The team's research looks at many different concepts, as ambient air has different components that could make a superfluorescent response. To verify that Argon and Nitrogen were the active components in the response, the team needed to monitor the coupling of the two in an oxygen-stable environment. The tests revealed some interesting results, including bidirectional lasing effects, which opened the door for a variety of new scientific experiments to begin.

Open-Air Lasers – Testing

The testing started with engineers using a 261 nm pump laser to excite the gases. The goal was to gain a deeper understanding of why the mixture of argon undergoes a reduction in ionization rate. This test led to the engineers focusing on the 3-photon resonant absorption of 261 nm photons in Ar. Here they discovered a direct correlation with the bidirectional lasing effect.

This bidirectional cascading lasing effect was tested using a variety of parameters to ensure the details of the conversion were recorded. The test revealed that mixing nitrogen with argon created the desired response, whereas other mixtures didn’t produce any bidirectional laser light pulse. Zooming in revealed that 3-photon absorption of 261 nm photons by Ar atoms specifically creates emission of cascaded superfluorescence. This revelation was a major discovery as it was previously unknown that a photon-mediated mechanism that transfers energy from N2 to Ar was a possibility.

The next steps began with frequency testing. Researchers shifted through different frequencies until they noticed that nitrogen molecules exhibit nonlinear-3-photon absorption in an electronically excited state when exposed for 261 nm to Argon resonating at a slightly different frequency. This data was then gathered to be used to create new formulas to model future experiments.

Results

The study shows some promising results that could upend the laser community. For one, the team successfully produced bidirectional cascaded lasting effects in atmospheric air. Specifically, the engineers were able to create two colored, bidirectional lasings via an open-air cavity-free setup.

The research also sheds light on some unexpected discoveries. For one, the team noticed that the amount of oxygen used during the mixture affected the interaction between the argon and nitrogen molecules. Their research shows that a 1% O2 mixture is ideal for cavity-free, bidirectional, and laser-like emission.

Open-Air Laser Benefits

This technology brings several benefits to the market. For one, it enables the creation of lasers with less mechanical parts. Open-air lasers will require less technical and manufacturing to produce. These lower costs will result in more use-case applications.

Stability

The use of mirrors in today's lasers is one of their greatest weaknesses. These tiny devices need to be calibrated perfectly and aligned to create the beam of light you expect. Any small deviation from the unit's original calibration can result in the device becoming useless. As the use of lasers continues to expand into large commercial and military applications, there is a strong demand for lasers with less moving components. Nitrogen Argon lasers are a smart solution.

Light Weight

Using lightweight Argon and Nitrogen will help reduce the overall weight of lasers moving forward. Lasers Are already in use on many microscopic devices. However, they are limited in the scale of operation based on the manufacturer's capabilities to shrink down the core components. An Argon-based system would require much less space and weigh less. As such, they could help power next-gen space travel, nanotech, and much more.

Potential use Applications

There are many applications for this new style of laser light. From monitoring and