Bridged Quaterphenyls as Flashlamp‐Pumpable Laser Dyes

Abstract

Partial bridging of the o,o′ positions of the aromatic rings in quaterphenyl gave superior flashlamp-pumpable laser dyes. Alkyl-substituted carbon bridges gave superior dyes to those containing oxygen or alkyl-substituted nitrogen or silicon bridges. Dyes lasing in the 365–390 nm region with improved energy output, lifetime and solubility were discovered.

Optical amplification and photodegradation in films of spiro-quaterphenyl and its derivatives

“…One of the organic semiconductors, which provides good emission in the blue [7] and near UV [8] spectral region, is the class of oligophenyls. Further advantages of oligophenyls are large Stokes shifts, high fluorescence quantum yields and high morphological stability of the amorphous form [7].…”

“…This is making them ideal candidates for organic solid state lasers. However, the solubility of the oligophenyls especially in polar non-toxic solvents is low which limits their application when spin coating is applied [8]. By introducing a spiro linkage between two oligophenyl molecules, the solubility of the new molecule (spiro-oligophenyl) is enhanced.…”

Cyclic Ether Auxofluors on Oligophenylene Laser Dyes

“…3'4 Both the quantum yield and the conversion efficiency can be restored, however, if ortho positions on adjacent rings are bridged by a single carbon substituted with gem-dialkyl groups. 5 Additionally these bridged oligophenylenes show dramatically improved solubility properties in useful laser solvents. Placement of t-butyl groups on the outer meta positions of quaterphenyl gives a dye with fairly high output, but very short lifetime.…”

“…Even BBQ, however, is not soluble enough in methanol or ethanol for practical use in those solvents. 5 Placement of alkoxy groups on either the outer meta positions or any internal ortho positions gives dyes with very short lifetimes. 4 For some time we have sought a way to extend the useful range of the laser emission of oligophenylene laser dyes beyond the ultraviolet into the visible.…”

Fluorene-Based Conjugated Oligomers for Organic Photonics and Electronics

“…The use of oligofluorenes as dye lasers was among the first indications of their excellent performance in lasers. When excited by excimer lasers or appropriate flashlamps, bifluorenes [202] up to tetrafluorenes [203] showed excellent lasing performance in the UV to deep blue. Outstanding among them is a laser dye now known as Exalite 428 (compound 52), marketed by Exciton Inc., shown in Fig.…”