Diode pumping of liquid crystal lasers

•Optical excitation of a liquid crystal laser is achieved by a 445 nm laser diode.•Single mode, narrow linewidth liquid crystal laser emission is accomplished.•Comparisons are made between Q-switched and laser diode pump regimes.•Diode-pumped red, green and blue liquid crystal laser emissions are demonstrated. Liquid crystal lasers are typically pumped with Q-switched lasers, which provide the short pulse durations necessary to produce band-edge liquid crystal laser emission. However, the current cost and bulk of the pump laser, relative to the liquid crystal component, limit the application potential of liquid crystal laser technology. A low-cost and compact alternative pump source has often been discussed within the liquid crystal laser community but has not yet been demonstrated. In this paper, a 445 nm laser diode was integrated with carefully selected electronics in an attempt to reproduce equivalent pump conditions to that achieved from a Q-switched laser, and then used to pump a liquid crystal laser. Successful band-edge lasing was achieved, demonstrating, for the first time, a clear threshold and single mode, narrow linewidth emission. Red, green and blue outputs from different liquid crystal lasers were also realised when pumped with the same laser diode, demonstrating the broad wavelength selectivity of liquid crystal lasers using a single low-cost, compact device.