Lanthanide photonics on the path to future: from gas lighting to optical computers

In 1891, Austrian scientist and entrepreneur Carl Auer von Welsbach filed a groundbreaking patent for a cotton mantle impregnated with cerium-doped thorium oxide, which converted the light and heat of gas lamps into a brilliant white glow. This marked the birth of lanthanide photonics and phosphor chemistry—a field that now underpins countless essential technologies, from solid-state lighting to cancer phototherapy and quantum computing information processing. This perspective explores the remarkable scientific journey of lanthanide photonics, highlighting recent breakthroughs and key developments. We begin with a historical overview before delving into fundamental advances including quantum chemical models, antenna effect and energy transfer mechanisms, the design of inorganic phosphors, the influence of electric and magnetic fields, molecular and circularly polarized luminescence, upconversion processes, and quantum bits. The final section focuses on cutting-edge applications, such as solid-state lighting, photovoltaics, mechanoluminescence, and biomedical innovations (optical imaging, cancer diagnosis, and photodynamic therapy), while briefly touching on other emerging uses. Rather than providing an exhaustive review, this article offers a concise yet broad overview of the field, spotlighting pivotal contributions from the past decade. Our goal is to capture the dynamism and interdisciplinary impact of lanthanide photonics as it continues to shape science and technology.