The challenges associated with developing a flexible defect-mode liquid crystal (LC) laser are addressed in this paper. To begin with, we discuss the process for creating a well-aligned photopolymerized film of chiral nematic LC using various surface alignment layers such as polyvinyl alcohol, sulphonic azo-dye and rubbed polyimide. A single mode flexible defect-mode laser is demonstrated with an excitation threshold fluence of 60μJ/cm2/pulse. In accordance with previous studies, results from simulations based on the 4×4 Berreman model show that the wavelength and the number of laser modes are determined by the thickness of the defect layer. The proposed flexible laser can be used to form lasers that can be integrated into conformable platforms and that can be used to control the beam direction without the need for additional optical components.
We have demonstrated a Liquid crystal (LC) analog phase modulator based on the flexoelectric-optic effect that can achieve full 2π phase modulation with sub-millisecond switching speed. The LC mixture in the device consists of the bimesogen CBC7CB with chiral dopant R5011 that can exhibit ±𝜋/4 rotation of the optic axis for an electric field of ±4.2Vμm^(-1). This is then converted to a ±π phase modulation with the aid of a chiral reflector and a quarter waveplate. The residual amplitude modulation is found to be very low, and we show how these elements can be combined to form a integrated device.