A team at MIT has proposed an innovative approach to generating laser beams using a Bose-Einstein condensate (BEC) comprised of radioactive atoms, such as rubidium-83. This method relies on the synchronized radioactive decay of the atoms, which naturally produces neutrinos during the decay process. In the quantum state of the BEC, this decay is expected to accelerate, thereby amplifying the emission of neutrinos. This phenomenon mirrors the way stimulated emission amplifies photons in traditional laser technology. The researchers are aiming to develop a tabletop demonstration to validate their concept. Should this initial phase succeed, the team anticipates that neutrino lasers could serve as a valuable tool for underground communication and provide a new source of radioisotopes for medical imaging and cancer diagnostics.
Published in Physical Review Letters, 2025. DOI: 10.1103/l3c1-yg2l
Reviving the Pinhole Camera for Infrared Imaging
Credit:
Kun Huang, East China Normal University
The concept of the pinhole camera, which has existed for thousands of years since its early forms in 4th century BCE China, is undergoing a revival. This device operates by allowing light to pass through a small aperture in a light-proof box, creating an inverted projection of the external scene on the interior wall. While lens-based imaging can suffer from distortion and has restrictions regarding depth of field and wavelength, scientists are harnessing pinhole technology to develop a prototype infrared imaging system, as detailed in a recent paper in the journal Optica.
The researchers utilized a laser to create an optical pinhole within a nonlinear crystal featuring a “chirped-period” structure. This configuration allows for the collection of light rays from a broader range of angles, resulting in an extensive field of view. The crystal’s unique optical characteristics facilitate the conversion of infrared images into visible light, which can then be captured by standard silicon-based cameras. Additionally, this process effectively reduces noise, making it suitable for operation in low-light environments.
To evaluate their prototype, the team employed 3D time-of-flight infrared imaging to capture an image of a matte ceramic rabbit and reconstruct its three-dimensional shape through synchronized ultrafast pulses. The technology behind the infrared pinhole camera shows potential for adaptation to far-infrared or terahertz wavelengths. Although still in the early stages of development, the authors project that their advancement could lead to more cost-effective, portable, and energy-efficient infrared imaging systems, with potential applications in night vision, industrial quality control, and environmental monitoring.
