Bright Ideas: 9/29/21 — Bessel Is Better For 3D Printing, Combined VCSELs Prove Possible And Powerful
By Abby Proch, former editor
When it comes to the Internet of Things (IoT), flexible electronic solutions are a must. But in many current applications, like inside smart phones, silicon-based parts are too rigid in both their physical and chemical properties to meet increasing technological demands. That’s why researchers with The Institute of Scientific and Industrial Research at Osaka University and Joanneum Research in Austria are developing organic LED (OLED) displays made from carbon-based organic molecules that can be controlled and altered with UV light.
According to the researchers, UV light alters the chemical structure of the dielectric polymer PNDPE by breaking bonds and creating “crosslinks between strands.” By directing the UV light exposure with a mask, researchers can “tune” circuit behavior, according to the research. Senior author Tsuyoshi Sekitani says this tech may prove useful in manufacturing ultra-lightweight wearable healthcare devices.
Also benefiting from a boost of innovation is the additive manufacturing industry. Researchers at Lawrence Livermore National Laboratory have claimed using Bessel — rather than Gaussian — beams in metal 3D printing reduces pore formation, thermal gradients, and melt pool instabilities, according to Phys.org. Laser powder bed fusion (LBPF) benefits from this bullseye-shaped beam because it offers self-healing and non-diffraction properties and produces “more robust tensile properties” than materials created with conventional Gaussian beams. Researchers say the innovation can create stronger, more refined parts; can be used with a variety of metals; and can be integrated into existing commercial printing systems.
Another breakthrough in laser technology is the successful combination of Vertical-Cavity Surface-Emitting Lasers into one single — and more powerful — laser. Once limited by their small stature, VCSELs are now being arranged in a geometric shape on a planar chip that “forces the flight to flow in a specific path—a photonic topological insulator platform.” According to phys.org, a team of German and Israeli scientists have put what was once theory into practice, producing a more compact and powerful geometric configuration of VCSELs that can support advancing technologies in medical, industrial, communication, and military applications.
Finally in laser developments, researchers at King Abdullah University of Science and Technology (KAUST) claim to have successfully created a 17x17 micrometer μLED, according to The Engineer. Long regarded as a near-impossibility because of the damage that occurs and the resulting light that’s lost when fabricating a device so small, the new bright red indium gallium nitride (InGaN) μLED is remarkably smaller than the customary 400x400 micrometer design.
The team used a calibrated atom technique to make a 10x10 array of red μLEDs and mitigated damage to the device sidewalls with a chemical treatment. Paired with green and blue, the red μLED creates a wide-range color device that researchers say is key for developing next-gen μLED displays. Next steps for the team include decreasing the device’s lateral dimensions even further — below 10 micrometers — and upping their efficiency.
In academia and the workplace, in-situ laser learning can be a costly and complicated endeavor, requiring elaborate equipment and experienced teachers to bring theoretical learning into practice. As a way to overcome these challenges, scientists at the Julius Maximilians University (JMU) of Wurzburg, Germany, have developed a virtual reality (VR) laser lab called femtoPro, according to Phys.org.
Donning just a VR headset, students and early learners enter a simulated laser laboratory where they can conduct experiments and manipulate optical tools just the way they would in a physical setting. According to the developers, the laser and all its optical elements are displayed in real time and according to all physical laws, even accounting for the Gaussian effect, refraction of light on glass, and color change. Another upside is that the virtual setting rules out the risk of dangerous mishaps. The team is debuting femtoPro at Highlights der Physick in Wurzburg through Oct. 2, 2021.
Finally, 105 years after its inception, the Optical Society of America (OSA) is changing its name to Optica, according to a news article published by the society. While more of a branding endeavor than a legal name change (which would take a membership vote), the new name is said to embrace the society’s growing global presence and widening field of study (to include photonics).
Though the name change appears sudden to some, the breadth of the society’s coverage has long been diverse and the quest for a new name has been in various stages of development for 30 years. In 1990, the society nearly changed its moniker to “The Optics and Photonics Society” until a few opposing voices stalled the process. Now, Optica has successfully replaced the time-tested name to mark the diverse and inclusive reality of optics and photonics. Its tagline is “Advancing Optics and Photonics Worldwide.”