We investigate radiation nanofocusing with channel plasmon polaritons (CPPs) propagating along subwavelength metal grooves that are tapered synchronously in depth and in width. Efficient CPP nanofocusing at telecom wavelengths with the estimated field intensity enhancement of up to approximately 90 is directly demonstrated using near-field microscopy. Experimental observations are concurred with electromagnetic simulations, predicting the possibility of reaching the intensity enhancements of approximately 1200 and opening thereby exciting perspectives for practical applications of CPP nanofocusing.

Channel plasmon polaritons (CPPs) can effectively nanofocus radiation at telecom wavelengths, potentially reaching intensity enhancements of up to 1200, offering exciting perspectives for practical applications.

Nanofocusing with channel plasmon polaritons.

Key Takeaway: Channel plasmon polaritons (CPPs) can effectively nanofocus radiation at telecom wavelengths, potentially reaching intensity enhancements of up to 1200, offering exciting perspectives for practical applications.