An organic material, 4,5-bis(benzoylthio)-1,3-dithiole-2-thione (BBDT), was synthesized. The thin film of BBDT doped
into poly(methyl methacrylate) (PMMA) was prepared using spin-coating method. Its linear optical properties were
characterized with prism coupler (SPA-4000, Korea). The third-order nonlinear optical (NLO) properties were
investigated using Z-scan technique with pulses of picoseconds at 532 nm. The Z-scan spectra reveal a strong nonlinear
absorption (reverse saturable absorption) and a positive nonlinear refraction. The nonlinear absorption coefficient is
calculated to be 1.302×10<sup>-9</sup>m/W. The nonlinear refractive index is 2.243×10<sup>-9</sup>esu. The results show that the film exhibits
a great nonlinear optical response.
A dmit<sup>2-</sup> salt: [(C<sub>4</sub>H<sub>9</sub>)<sub>4</sub>N]Au(dmit)<sub>2</sub> was synthesized. Its third-order nonlinear optical properties of its acetone solution
were investigated by Z-scan technique using a pulsed laser with 28 ps duration and 10 Hz repetition at 532 nm. The
third-order nonlinear refractive index n<sub>2</sub> and nonlinear absorption coefficient β of the sample solution were obtained to
be about 4.997×10<sup>-12</sup> esu and 1.818 cm/GW at the concentration of 2×10-3 M. The second-order hyperpolarizability for
its molecular was estimated to be as large as 2.74×10<sup>-31</sup> esu, suggesting [(C<sub>4</sub>H<sub>9</sub>)<sub>4</sub>N]Au(dmit)<sub>2</sub> is a promising material for
The paper proposes the design of Home Gateway used in FTTH. On the customer's
side, the Home Gateway finishes the optical signal receiving, provides three kinds of interfaces for
the video, voice data, and attains the integration of the three services. PAS6301 chip achieves the
control of voice, video and data services. Especially on the aspect of the video services, the HG
system combines the advantages of IPTV and the DVB to offer a platform for receiving two
signals. Users can use ordinary TV to receive both digital TV programs encoded by MPEG-2 and
IPTV programs encoded by H.264.
VoD is a very attractive service which used for entertainment, education and other purposes. In
this paper, we present an evolution method that integrates the EPON and SCM-PON by WDM
technology to provide high dedicated bandwidth for the metropolitan VoD services. Using DVB,
IPTV protocol, unicasting and broadcasting method to maximize the system throughput and by
numerical analysis, the hybrid PON system can implement the metropolitan VoD services.
Bismuth titanate, Bi4Ti3O12 (BTO), is a typical ferroelectric material with useful properties for optical memory,
piezoelectric and electro-optic devices. Its nano-crystals were compounded by the chemical solution decomposition
(CSD) technique. The structure and size of BTO were analyzed by X-ray diffraction (XRD) and transmissive electron
microscopy (TEM). Three sorts of composite films BTO/PEK-c with different BTO concentration were prepared by
spin-coating method at certain conditions. In this article, the scattering losses in thin films were obtained using the
photographic technique. The losses in the films with different BTO weight ratios were compared and analyzed.