Polymethine materials with solid-state third-order optical susceptibilities suitable for all-optical signal-processing applications

Abstract

† Electronic supplementary information (ESI) available: Materials and methods, including characterising data for new compounds, details of linear and nonlinear optical characterisation, and theoretical methodology; additional linear spectra, including those for neat chromophore lms; and representative Z-scan spectra. See

Conjugated Polycyanines: A New Class of Materials with Large Third‐Order Optical Nonlinearities

“…Recently, polymethine dyes with large rigid groups bound to bridge and end groups were demonstrated to provide an effective mechanism to decrease chromophore–chromophore interactions as well as chromophore–counterion interactions. In this manner, material FOMs >12 and reasonable low linear loss were realized . However, an alternative approach is to design structures having symmetry persistent repeating cyanine units with shorter L that are fully conjugated with each other to form conjugated polycyanines.…”

“…The TCF‐heptamethines have been shown earlier to have large χ (3) values at 1.55 μm that are three times larger than that of silicon. [15a] We have introduced two rigid and bulky substituents (carbazole and fluorene moieties) into the center of a seven sp 2 ‐hybridized carbon atom (C7) based conjugation bridge for AJMPC02 and AJBC1730, which function as efficient spacers that possess an out of plane configuration of the chromophore π‐system to prevent unwanted aggregation between polycyanine chains . Considering that PC2 has been reported to possess rather poor solubility and processibility, we have functionalized the spacers with solubilizing substituents ( tert ‐butyl group) to improve solubility and processibility of the resulting polymers.…”

“…The synthetic route of making polycyanine and its salt complex is shown in Scheme . The C7‐conjugating bridge 1 was synthetized as reported, and the bifunctional “Janus core” of 2 was synthesized according to methods reported in the literature . By refluxing in ethanol using sodium acetate as base, cationic polyindolinium of AJMPC02 and anionic TCF‐cyanine of AJBC1730 could be prepared with good yields of 93.1% and 86.8%, respectively.…”

Hemicyanine dyes linked with quaternary ammonium group: Near-infrared probes for the detection of nucleic acid

“…Cyanine has attracted interest for its use as a functional dye in material [10][11][12][13] and biological applications [14][15][16]. However, normal cyanines have the disadvantage of limited Stokes shifts.…”

Spectral, morphological, linear and nonlinear optical properties of nanostructured benzimidazole metal complex thin films

“…Organic materials offer low cost fabrication and flexible design possibilities [3,4]. But, the main disadvantages of organic materials are lack of good thermal and mechanical durabilities, and exhibit more optical scattering losses.…”