Discovery of Novel Dyes with Absorption Maxima at 1.1 μm

Abstract

During the process of developing organic molecules that match the wavelengths used in optical communications, we have discovered a new class of dyes, with absorption maxima at 1.1 mum, and clarified their molecular structures. The synthesis of this class of dyes was supposed to involve unexpected intramolecular tandem reactions, and the effect of alkyl substituents on such a synthesis was investigated. As a result, an effective alkyl-substituent structure for realizing a high synthetic yield and good solubility in organic solvents was found. Furthermore, thin films made of such a highly soluble dye were fabricated by solution-coating, and they exhibited a red-shifted absorption band with a maximum at approximately 1.3 mum, indicating the formation of J-like aggregates. The third-order nonlinear optical susceptibility chi(3) of these thin films at 1.3 mum, which is the wavelength used in optical communications, was measured by the Z-scan technique. The magnitude of chi(3) reaches approximately 10-7 esu. These results suggest that the solution-coated thin films of this type of dye are potential materials for optical switching at 1.3 mum and for other nonlinear optical applications.

An Unexpectedly Simple NIR Dye for 1.1 μm with a Central Mesoionic Structure

“…[8] An even further bathochromic shift of the absorption to 1228 nm was then obtained by J-aggregation [9] of the new dye 4 (Scheme 1); this absorption is of special interest for optical components.…”

“…The remark of the authors [8] concerning a strongly shortened N-aryl bond length by pronounced mesomeric effects is important for the understanding of the special electronic conditions in 4 a. Its chromophoric structure can be interpreted in terms of the donor-acceptor-concept established by König [10] and Ismailsky, [11] and further developed by Dilthey and Wizinger [12][13][14][15] and incorporated into the perturbation molecular orbital theory (PMO) model by Dewar.…”

NIR Absorption of Perylene Dyes and Fluorescence with Large Stokes’ Shift by Simple Deprotonation

“…[3]. Bathochromically absorbing smaller molecules are more difficult to obtain [4], but can be developed by balancing substituent effects in conjugated π systems; compare ref. [5] and refs.…”

Ultrafast photoresponsive materials and molecular photonics applications by guided wave mode geometry

“…Since silica-based optical fibers which are employed worldwide in such systems show minimum transmission loss at about 1260-1675 nm, photoresponsive materials are needed to show ultrafast absorption or refractive index changes in such nearinfrared (NIR) region. Many types of ultrafast optical processing devices and semiconductors or organic materials have been studied so far [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Single shot demultiplexing of 1 THz light pulses was proposed on the basis of transient bleaching of organic dye J-aggregate films [3][4][5][6].…”

“…Many types of ultrafast optical processing devices and semiconductors or organic materials have been studied so far [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Single shot demultiplexing of 1 THz light pulses was proposed on the basis of transient bleaching of organic dye J-aggregate films [3][4][5][6]. Single-walled carbon nanotubes and expanded porphyrin derivatives are also expected for ultrafast optical switching in the NIR region [7][8][9][10].…”