Nonlinear optical properties of an organic film formed of dye aggregates with absorption in the telecommunication wavelength range

Abstract

An organic film formed of newly synthesized dye aggregates with an absorption peak in telecommunication wavelength range exhibited large third-order nonlinear optical susceptibility χ(3) and fast recovery of bleached absorption. A derivative with a di(benzofuranonyl)methanolate structure forms stable aggregates in a spin-coated film and shows an absorption maximum at 1.24 μm. An imaginary part χI(3) of the film assumes a maximum at 1.30 μm, which is −0.83×10−7 esu. The time evolution of differential transmission spectra indicates that the time constant of the recovery of bleached absorption is 80–240 fs for a fast component and 2.2–6.5 ps for a slow one. This organic film has considerable advantages for future planar optical devices.

Third-order nonlinear optical properties of the phenothiazinium chlorides at 532nm

“…Materials with resonance structures were selected for NLO research owing to their potential large fluctuation of electrons or large polarizable p-bridge. Current research, such as investigations on BM4i4i [17,18], croconates [20] and squaraine compounds [19], show the general character of resonance structures serving as NLO materials as follows: the organic molecule has more than two stable conjugated resonance structures, electron donor and/or acceptor groups participate in the resonance, and resonance structures can be well consistent with the classical VB structures. Considering the complexities of third-order NLO properties, more experimental examples are needed to explore the role of resonance stabilization and delocalized structures in predicting thirdorder NLO properties of materials.…”

“…The third-order NLO properties of di(benzofuranonyl)methanolate (BM4i4i, Fig. 1) film gave an exciting result with the imaginary part of the third-order NLO coefficient c I (3) ¼ À0.83 Â 10 À7 esu [17,18]. Nonsymmetric squaraine compounds with directional charge transfer character were recently designed for second harmonic generation research [19].…”

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

“…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].…”

“…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].…”

“…Ultrafast switching materials which work in less than 1 ps are essential for teraherz (THz) communication. Several attempts have been reported for this purpose, which include optical switching by tunneling bi-quantum well semiconductors or organic materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14].…”