Distributed feedback lasing from thin organic crystal based on active waveguide grating structures

A simple method has been proposed to fabricate active waveguide grating structures as distributed feedback configuration for organic crystal lasers. Organic single crystals, 2,5-bis(4-biphenyl)bithiophene (BP2T), act as both the gain medium and the waveguide. The distributed feedback structures are fabricated separately on top of crystals through interference lithography. The lasing emissions centered at 566 nm with FWHM of 1.1 nm have been observed when the pump intensity exceeds 19 μJ cm−2. This method features simple, nondestructive, and it is expected to be applied in the electronically pumped laser devices.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Organic single crystals have been introduced as active medium in the lasers. ► We realize second order DFB lasing emissions from the crystals by this method. ► We improve the crystal device performance by avoidance of micromachining. ► This method may greatly maintain the intrinsic properties of crystal.