Organic lasing using distributed feedback reflectors fabricated by electron irradiation

Abstract

A simple approach to producing a distributed feedback (DFB) laser is explored. In this work, periodic diffraction grating is fabricated by direct electron-beam patterning of a conjugated polymer. Electron irradiation alters the refractive index of the polymer, allowing a distributed feedback reflector (DFR) to be fabricated directly by appropriately irradiating certain areas of the polymer. The irradiated polymer does emit light, but the intensity and the wavelength of its emission are significantly affected. The pristine (non-irradiated) sections of the system serve as the primary gain medium, while the irradiated sections provide the necessary refractive index difference. The applicability of the approach introduced in this work is not limited to just the polymers tested in this paper

by carefully determining the appropriate grating period, it can be applied to other gain media to achieve lasing at various wavelengths. The detailed methodology by which a distributed feedback laser is fabricated via electron irradiation is discussed along with the advantages such an approach can provide over the conventional.