Tunable polymer lasers based on metal-dielectric hybrid cavity.

Abstract

Tunable distributed feedback polymer lasing was achieved in a metal-dielectric hybrid cavity. The laser device consisted of a double-layer grating structure and a polymer membrane. Interference lithography and oblique evaporation techniques were employed in fabricating the cavity. The photoresist grating was fabricated by interference lithography. Silver was obliquely evaporated onto the photoresist grating, forming a double-layer grating structure. Then a free-standing polymer membrane was attached on the structure. Under optically pumped conditions, low-threshold lasing was obtained, due to the plasmonic enhancement. The lasing wavelength can be tuned by changing the silver grating's thickness, which results from the variance of the effective refractive index of the cavity. These results can be used to design high-efficiency laser devices.