Researchers at the University of Ottawa have made a groundbreaking discovery in light interaction, showing for the first time that light can create shadows by blocking other light, akin to how solid objects cast shadows. Led by Associate Professor Jeff Lundeen and the Boyd Research Group, the team conducted experiments using a green laser and a ruby crystal, revealing that a laser beam can act like a solid object to cast a visible shadow. They demonstrated that under specific conditions, a laser can prevent other light from passing through, creating a dark area on a surface. The research involved shining a green laser through a ruby crystal while illuminating it with blue light from the side, resulting in a shadow that closely resembled traditional shadows. The intensity of the shadow varied with the power of the green laser, achieving a contrast comparable to typical shadows experienced outdoors. This finding not only challenges existing notions of light behavior but also opens new avenues for applications in optical switching, fabrication, and imaging technologies. The work highlights the significance of fundamental research in advancing our understanding of light-matter interactions and its potential impact on future innovations in photonics and non-linear optics.
