For decades, shrinking photonic devices has been far more difficult than miniaturizing electronic components. The challenge comes down to physics. Light cannot easily be confined into extremely small spaces because the uncertainty principle links its confinement to its wavelength. In visible and near infrared light, that wavelength can be up to a thousand times larger than the de Broglie wavelength used in electronic circuits. As a result, photonic chips have remained relatively bulky, and optical imaging systems have faced strict resolution limits.
Scientists previously explored plasmonics as a possible workaround. That approach uses metals to squeeze light into spaces smaller than its wavelength. However, metals generate significant heat through energy dissipation, creating a major obstacle for efficient and scalable photonic technologies.
In 2024, researchers led by Ren-Min Ma at Peking University in China introduced a major breakthrough [Nature 632, 287-293 (2024)]. The team developed what they call the singular dispersion equation, a new theoretical framework showing that light can be confined to extraordinarily small scales using lossless dielectric materials instead of metals. Because the method relies entirely on dielectrics, it avoids the heat losses that have limited plasmonic systems and could help pave the way for compact, energy efficient photonic devices.
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