https://phys.org/ en-us Latest news from Institute of Electrical and Electronics Engineers Cerebral blood flow is essential for normal brain function and often perturbed in neurological disease. If one shines a source of coherent light on perfused tissue, the detected speckles, or "grains" of light fluctuate, or "dance," at a rate proportional to blood flow in the volume sampled by the light. In brain tissue, this concept can be harnessed to measure the cerebral blood flow index (CBFi). https://phys.org/news/2026-03-gen-interferometric-diffusing-spectroscopy-20x.html Optics & Photonics Sat, 14 Mar 2026 13:00:04 EDT news692509973 Ultrashort mid-infrared (mid-IR) laser pulses are essential for applications such as molecular spectroscopy, nonlinear microscopy, and biomedical imaging, but their generation often relies on complex and power-intensive systems that are difficult to implement outside of specialized laboratories. These systems usually require high pump powers, elaborate optical setups, and precise alignment, which can limit their widespread adoption and practical use in everyday research and clinical settings. https://phys.org/news/2026-03-fiber-setup-compresses-mid-infrared.html Optics & Photonics Wed, 11 Mar 2026 18:10:06 EDT news692465401 Efficient generation and reliable distribution of quantum entangled states is crucial for emerging quantum applications, including quantum key distribution (QKDs). However, conventional polarization-based entanglement states are not stable over long fiber networks. While time-bin entanglement offers a promising alternative, it requires complex infrastructure. In this study, researchers explore how stable time-bin entangled states can be generated and distributed using commercially available components, paving the way for practical quantum communication networks. https://phys.org/news/2026-02-shelf-components-enable-deployment-ready.html Optics & Photonics Tue, 17 Feb 2026 15:47:57 EST news690565621 Quantum key distribution (QKD) is an emerging communication technology that utilizes quantum mechanics principles to ensure highly secure communication between two parties. It enables the sender and receiver to generate a shared secret key over a channel that may be monitored by an attacker. Any attempt to eavesdrop introduces detectable errors in the quantum signals, allowing communicating parties to detect if communication is compromised via QKD protocols. https://phys.org/news/2026-01-errors-impact-quantum-key.html Quantum Physics Mon, 19 Jan 2026 15:30:06 EST news688058563 Free-space optical communications (FSOC), which use lasers for data transmission, are a promising approach for achieving high-speed links between aircraft, spacecraft, and ground stations. However, achieving 360-degree coverage requires multiple articulated terminals installed on the fuselage of aircraft, exceeding size, weight, and power limits. https://techxplore.com/news/2025-12-optical-fiber-bundles-solution-high.html Telecom Wed, 17 Dec 2025 20:30:01 EST news685196917 Geiger-mode avalanche photodiodes (GM-APDs) are highly sensitive light detectors, capable of detecting single photons. Photons of certain wavelengths, when absorbed by photodiodes, generate electron-hole pairs in a process called impact ionization which can result in a multiplication of charges when occurring in an electric field. https://phys.org/news/2025-11-optimizing-avalanche-photodiode-photodetection-ultraviolet.html Optics & Photonics Tue, 04 Nov 2025 14:49:03 EST news681490141 Nonlinear optical dynamics—intensity-dependent response of light upon interaction with materials under high-intensity light sources—are of huge significance in modern photonics, finding applications in fields ranging from lasers, amplifiers, modulators, and sensors to the study of topics including quantum optics, nonlinear system dynamics, as well as light-matter interactions. https://phys.org/news/2025-10-team-photonics-advances-free-electron.html Optics & Photonics Fri, 31 Oct 2025 12:22:09 EDT news681132123 Optical signal transmission can be significantly improved by limiting the wavelength of transmitted signals. Fiber Bragg grating (FBG) is a technique widely used in optical communication, sensing, and laser technologies for selectively blocking certain wavelengths of light. In optical fibers, FBG functions as a band-rejection filter that reflects specific light wavelengths, but allows others to pass unimpeded, offering advantages such as improved signal transmission quality, reduced signal loss, and high signal specificity for sensing applications. https://techxplore.com/news/2025-09-advanced-broadband-optical-filtering-chirped.html Engineering Mon, 15 Sep 2025 15:23:44 EDT news677168621 Multi-wavelength light sources are required for optical transceivers to increase data. However, scaling the laser array size increases thermal crosstalk, which may affect laser efficiency and reliability. https://phys.org/news/2025-07-high-density-laser.html Optics & Photonics Mon, 21 Jul 2025 12:10:07 EDT news672316948 Lasers that are fabricated directly onto silicon photonic chips offer several advantages over external laser sources, such as greater scalability. Furthermore, photonic chips with these "monolithically" integrated lasers can be commercially viable if they can be manufactured in standard semiconductor foundries. https://phys.org/news/2025-07-efficient-quantum-dot-lasers-silicon.html Optics & Photonics Fri, 18 Jul 2025 10:20:04 EDT news672050613