Liquid Crystalline Azobenzene-Containing Polymer as a Matrix for Distributed Feedback Lasers
For the first time a liquid crystalline azobenzene-containing side-chain copolymer was employed as matrix material for distributed feedback lasers based on orientation gratings. Effective polarization gratings with periods of 245-290 nm could be inscribed within just one second using moderate light intensity. Using a number of near-infrared laser dyes and different grating frequencies, tuning of wavelength of the emitted radiation from 760 to 883 nm was obtained. It was also found that the lasing wavelength depends on the angle between the liquid crystal director and the grating vector. Wavelength tuning in the range of 30 nm was demonstrated using this method.