Bright Ideas — New Research Avenues In Photonics, Photonics Chip Allows Light Amplification, And A 20-Year-Old Optical Light Mystery Is Solved
By John Oncea, Editor
Bright Ideas presents the most captivating news and innovations in optics and photonics. This week, we look at a simple and effective chip-scale isolator created by Stanford researchers, check out newly developed integrated circuits that can be employed for optical signals like those used in Lidar, and find out how uOttawa researchers figured out how to differentiate the enantiomers of a chiral molecule using helical light beams.
Researchers at Stanford University say they have created a simple and effective chip-scale isolator that can be laid down in a layer of semiconductor-based material hundreds of times thinner than a sheet of paper, according to Phys.org. “Chip-scale isolation is one of the great open challenges in photonics,” said Jelena Vučković, a professor of electrical engineering at Stanford and senior author of the study. Alexander White, a doctoral candidate in Vučković's lab and co-first author of the paper, added, “Every laser needs an isolator to stop back reflections from coming into and destabilizing the laser.” White further noted that the device has implications for everyday computing, but could also influence next-generation technologies, like quantum computing.
Medical Xpress reports that Lihong Wang, Caltech's Bren Professor of Medical Engineering and Electrical Engineering, and his team have developed a new variant of PAM called needle-shaped beam photoacoustic microscopy, or NB-PAM, which that has a depth of field nearly 14 times greater than what was achievable before. This means NB-PAM can create 3D imagery of samples without refocusing and better image samples with uneven surfaces. “This technology provides new opportunities for studying tissue samples during surgery, which would allow complete removal of cancer cells and maximal preservation of normal ones,” says Wang. “Translation into the operating room is a natural future avenue of research.”
Scientists at EPFL announced a study led by Dr. Johann Riemensberger that developed a traveling-wave amplifier based on a photonic integrated circuit operating in the continuous regime. “Our results are a culmination of more than a decade of research effort in integrated nonlinear photonics and the pursuit of ever lower waveguide losses,” said Riemensberger. “The application areas of such amplifiers are unlimited,” said Tobias Kippenberg, head of EPFL’s Laboratory of Photonics and Quantum Measurements at EPFL. “From optical communications where one could extend signals beyond the typical telecommunication bands, to mid-infrared or visible laser and signal amplification, to LiDAR or other applications where lasers are used to probe, sense and interrogate classical or quantum signals.”
Convergent Photonics is developing news sources for high-power industrial and mid-power medical laser applications thanks to the introduction of a new chip-on-submount (CoS) package for 445nm blue laser diodes from ams Osram, according to optics.org. For medical applications, the same technology – also combining multiple blue CoS lasers from ams Osram – is integrated with control electronics to provide a very compact stand-alone source.
A University of Ottawa research team developed a new chiroptical technique to differentiate the two non-superimposable mirror images of a chiral molecule. Its efficiency can even be scaled and controlled by using linear polarized helical light beams, according to the university. “Our understanding of light-matter interactions is mainly based on the propagation of homogeneously polarized light and the dominance of the dipole-active transitions between different quantum states of matter,” explained team member Jean-Luc Bégin. “The higher-order multipole effects are often ignored. Our findings demonstrate their importance.”
The Optica Foundation issued details on the healthcare work being funded by its 20th Anniversary Challenge. This newly funded research will address the potential of Differential Interference Contrast (DIC) microscopy, accessibility and portability of Optical Coherence Tomography (OCT), and applicability of Synthetic Wavelength Holography (SWH), a method to image through light-scattering materials like human skin. “The field of imaging has benefited greatly from advances in photonics,” said Majid Ebrahim-Zadeh, ICFO - Institut de Ciencies Fotoniques, Spain, and member of the 20th Anniversary Challenge Selection Committee. “The research being conducted by the challenge recipients strives to solve today’s pain points in imaging, including efficiency and accessibility. We expect these efforts to lead to continued investigation and advancement in this critical field.”
The University of Strathclyde announced it has developed a programmable optical device for high-speed beam steering. The wireless device can control light, such as by focusing a beam in a specific direction or manipulating the light’s intensity and do so in orders of magnitude more quickly than commercial devices. The device demonstrated near-perfect control — in both space and time — of an optical field with a joint “spatiotemporal bandwidth” 10 times greater than that of existing SLMs. Being able to precisely control a huge bandwidth of light could enable devices that can carry massive amounts of information extremely quickly, such as high-performance communications systems.