MIT builds self‑organizing laser
- MIT researchers reported on April 27 that chaotic light in a standard multimode fiber can self-organize into a tightly focused “pencil beam” for imaging. - In Nature Methods, the team said the beam captured 3D images of a human blood-brain barrier model 25 times faster than standard imaging. - The work could speed tests of whether Alzheimer’s or ALS drugs reach brain targets. (news.mit.edu)
A laser is usually supposed to get messier as you push more power through a fiber. MIT researchers reported April 27 that, near a critical power level, the opposite can happen: the light collapses into a narrow “pencil beam.” (nature.com) (news.mit.edu) The fiber in the study was a standard multimode optical fiber, the kind that lets light bounce through many paths at once. That usually produces a scrambled output, but the MIT team found a stable, self-localized ultrafast beam near the fiber’s critical power. (nature.com) The paper was led by Honghao Cao and senior author Sixian You of the Massachusetts Institute of Technology, with co-authors from MIT, Harvard University, and Beth Israel Deaconess Medical Center. Nature Methods published the study on April 27, 2026. (nature.com) (eurekalert.org) To show what the beam could do, the researchers used it in multiphoton microscopy, a technique that builds 3D images by scanning tissue with ultrafast pulses of light. They imaged a human blood-brain barrier model at speeds 25 times faster than a gold-standard method while keeping comparable resolution. (nature.com) (eurekalert.org) The blood-brain barrier is the layer of cells that controls what gets from the bloodstream into brain tissue. The MIT team said faster 3D imaging could let researchers watch individual cells take up drugs in real time. (news.mit.edu) (eurekalert.org) That matters for brain diseases because many drug candidates fail at the barrier before they ever reach neurons. MIT said the method could help scientists test delivery for neurodegenerative diseases including Alzheimer’s disease and amyotrophic lateral sclerosis, or ALS. (news.mit.edu) The researchers traced the effect to nonlinear optics, where intense light changes the medium it travels through and reshapes its own path. In this case, the beam organized itself inside the fiber instead of requiring a more complex external beam-shaping setup. (nature.com) (photonics.com) You said the team wants to better understand the underlying physics and the mechanism behind the beam’s self-organization. For now, the result is a simpler way to turn a normally chaotic fiber output into a tool for fast volumetric imaging. (genengnews.com) (news.mit.edu)
