Multi-wavelength lasing in a beat structure.

Multi-wavelength polymer lasers are produced with one-dimensional beat structures fabricated with multiple gratings at the same substrate location using interference lithography. As a distributed feedback cavity, the beat structure is equivalent to a linear superposition of multiple grating cavities. Each emission wavelength is determined by the corresponding grating cavity, which implies that interaction between different cavities is very weak. For a beat structure consisting of three gratings, emission peaks at 558 nm, 565 nm, and 569 nm originate from 350-nm, 362-nm, and 374-nm cavities, with thresholds of 14.5μJ/cm2, 15.0μJ/cm2, and 13.5μJ/cm2, respectively. This technique provides an alternative way to design compact polymer lasers. [ABSTRACT FROM AUTHOR]