Electrically controllable plasmonic enhanced coherent random lasing from dye-doped nematic liquid crystals containing Au nanoparticles

Abstract

An electrically controllable plasmonic enhanced coherent random lasing from the dye-doped nematic liquid crystal containing Au nanoparticles is demonstrated. To achieve the optimal control of the RL properties, the polarization of the pump light should be parallel to the rubbing direction of the cells. The lasing output intensity is direction-dependent and the substantial output distributes in an angle range of 0°~30° deviating from the direction of the pump stripe. The coherent feedback associated with the coherent random lasing mainly originates from the cooperative effect of the enhanced localized electric field in the vicinity of Au nanoparticles and the multiple scattering caused by the fluctuations of the liquid crystal director and local dielectric tensor.

A RGB random laser on an optical fiber facet

“…Over the past decade, plasmonic random lasers have attracted considerable attention because of their great potential for use as display and sensing devices. [1][2][3][4][5][6][7][8] The lasing threshold of a plasmonic random laser is much lower than that of a conventional random laser because of its large scattering cross-section and the localized surface plasmon resonance of the metal nanoparticles (NPs) used in the structure. [9][10][11][12][13] Additionally, red-greenblue (RGB) plasmonic random lasers have been studied as potential multicolor output devices.…”

Magnetically controllable random laser in ferromagnetic nematic liquid crystals

“…Because the laser action is correlated with the orientational direction of liquid crystals [15], it could respond to the molecular reorientation by a variety of external stimuli. In fact, the wavelength, intensity and polarization of the random laser in NLCs can be controlled by electrical [16][17][18][19], thermal [13,20] and magnetic [19] stimuli, and the alignment of LC cells [15,21]. In particular, the optical switching owing to the molecular reorientation in a magnetic field [22] has some advantages in remote operability [8].…”

Pump-Controlled Plasmonic Random Lasers from Dye-Doped Nematic Liquid Crystals with TiN Nanoparticles in Non-Oriented Cells

“…In the past few decades, a wide range of materials, such as semiconductor [7], π-conjugated [8], human tissues [9], quantum dots [10], metallic nanoparticles [11,12], polymers [13], and liquid crystals (LCs) [14][15][16] have been used to realize random lasers. Metal nanoparticles, such as gold (Au) nanoparticles and silver (Ag) nanoparticles are often used to enhance the performances of random lasers [11,12,[17][18][19][20]. For example, Dice et al [17] reported in 2005 that the random lasers formed by suspending Ag nanoparticles in the laser dye solution.…”