Plasmonic random laser from dye-doped cholesteric liquid crystals incorporating silver nanoprisms

Abstract

Plasmonic random lasers have been demonstrated in combining dye-doped cholesteric liquid crystals (DD-CLCs) and silver nanoparticles (AgNPs). The DD-CLC laser reveals the lowest threshold and highest slope efficiency through the localized surface plasmon resonance of AgNPs with the best coupling of the emission spectrum of lasing dye and resonance of electron oscillation on the metal surface. Thermal control of the DD-CLC lasers has been achieved to simultaneously shift the long- and short-edge lasing peaks. By the α -stable analysis, the DD-CLC random laser (RL) reveals heavy tail distribution with relatively low α ∼ 1.06 to show the Lévy behavior. Owing to its low spatial coherence, the DD-CLC RL has been demonstrated to produce a speckle-reduced image with a lower contrast of about 0.04.

Polarized Stimulated Emission of 2D Ensembles of Plasmonic Nanolasers

“…The properties of subwavelength lasers are constantly improving; several groups have dealt with low‐threshold for lasing, [ 29–32 ] multiwavelength lasing, [ 33 ] and high external quantum efficiency. [ 34 ] Despite the cogent results that spaser‐based nanolaser have demonstrated, there are several negative responses to plasmonic nanolasers, particularly because the lasing can be interpreted as a stimulated emission in a random laser [ 35,36 ] or as an amplified spontaneous emission. [ 37–43 ]…”

Plasmonic random lasing and amplified spontaneous emission from donor–acceptor–donor dyes covered biocompatible silk fibroin film

“…Through proper tailoring of the morphology and the position of SPR of MNPs to achieve a better overlap with dye fluorescence, the output performance of random lasing can be enhanced, and is termed a PRL. 4,7…”

“…Through proper tailoring of the morphology and the position of SPR of MNPs to achieve a better overlap with dye fluorescence, the output performance of random lasing can be enhanced, and is termed a PRL. 4,7 With the above-mentioned preliminary ASE properties of these DC-SF films, we further try to investigate the characteristics of plasmonic random lasing based on the side emission of DC-SF/ AgNPs via the setup shown in Fig. 7(a), the corresponding photo is shown in the bottom of Fig.…”

“…S8 in ESI †), the threshold of PRL based on the DC-SF/AgNPs film exhibits a saliently decreased threshold (i.e., from 6.24 to 3.99 mJ cm À2 ) and an increased slope efficiency, which could be attributed to the large scattering cross-section due to the embedded AgNPs. 4,7 The energy coupling between the emitted light and the oscillated electron on the metallic surface (as depicted in the illustration at the top of Fig. 7(c)) will lead to the improvement of RL efficiency.…”

“…2 By means of their broad emission bandwidth, structural tunability and large stimulated emission cross section, organic laser dyes have played a vital role in the development of ultrafast lasers and have been recognized as promising gain media in emerging laser systems. To date, many commercially available laser dyes such as rhodamine 6G (R6G), pyrromethene 597 (PM597) and dichloromethane (DCM) 3 have been adopted as active media to produce random lasers (RLs) in cooperation with nanostructure materials such as liquid crystals, 4 TiO 2 , 5 polymers 6,7 and electro-spun fiber. 8 In contrast to conventional lasers with cavity mirrors, the generated photons of RLs can be efficiently trapped in a disordered nano-structure by recurrent light scattering to form a number of closed loops.…”