High slope efficiency liquid crystal lasers

In this letter, we demonstrate high slope efficiency laser emission from reflective liquid crystal laser devices with a silicon backplane. Three different cell architectures were fabricated and each resulting laser device was then characterized in terms of the excitation threshold and the slope efficiency when optically excited close to the absorption maximum of the gain medium (pyrromethene 597). By combining a high gain medium with double-pass geometry, as well as the optimum cell thickness, the results demonstrate that it is possible to reduce thresholds by 25% and achieve slope efficiencies as high as 60%.