Manipulation of Polarized Random Lasers from Dye-Doped Twisted Nematic Liquid Crystals Within Wedge Cells

The characteristics of polarized random lasers (RLs), made from dye-doped twisted nematic liquid crystals (DD-TNLCs) in a wedge cell, have been investigated. Regardless of the multiple light scattering within disordered LCs inside the cell, the output polarization is compulsorily determined by the rubbing direction of PI on glass plate. Moreover, the output intensity of the RLs can be manipulated by the orientation of the linear pump polarization relative to the rubbing direction of polyimide on the incident glass plane. Through thermal control, the resonance characteristics of the RLs can be altered to generate the highest slope efficiency and lowest lasing threshold at 25 °C. The measured results indicate abundant and intriguing optical and physical properties of the DD-TNLC laser.