Yijun Guan

Synthesis of Azo Polyurethane-Urea and Investigation of its Thermo-Optic Properties

Abstract An azo chromophore molecular S(-)-1,2-bis(4-azophenyl-4-nitro)-ethylenediamine (OABANEDA) was synthesized with 4-nitroaniline and S(-)-1,2-diphenyl ethylenediamine by diazo-coupling reaction. The azo polyurethane-urea (OAAPUU) was obtained from OABANEDA, polyether diol (NJ-210) and isophorone diisocyanate (IPDI). The structure of OAAPUU was characterized by the Fourier transform infrared and UV-visible spectroscopy. The physical and mechanical properties of OAAPUU were investigated. The refractive index (n) and transmission loss of OAAPUU film were measured at different temperatures and different laser wavelengths (532 nm, 650 nm and 850 nm) by an attenuated total reflection (ATR) technique and CCD digital imaging devices. A Y-branch and Mach–Zehnder interferometer (MZI-type) switches based on thermo-optic effect of OAAPUU film were designed and simulated. The result showed that the power consumption of the Y-branch switch and the MZI-type switch could be only 0.52 mW and 1 mW, while the response times of the two types switches reach about 0.2 ms and 0.01 ms, respectively.

Helical Biphenyl Bisazo Polyurethane: Preparation, Characterization and Analysis of Polymeric Thermo-Optic Switch

The bisazo chromophore molecule (CAAPM) and helical biphenyl bisazo polyurethane (HBBPU) were synthesized. The structures of CAAPM and HBBPU were characterized by FT-IR and UV-vis spectroscopic techniques. The measurements of refractive index and thermo-optic coefficient (dn/dT) of HBBPU were demonstrated at different wavelengths and different temperatures by the ATR technique. By using CCD digital imaging devices, transmission loss of the internal waveguide was measured. The refractive index dispersions and Sellmeyer coefficients of HBBPU were obtained by the Sellmeyer equation. A Y-branched switch based on the thermo-optic effect was proposed and the performance of the switch was simulated. With a branching angle of 0.143° and the FD-BPM method, the result showed that the power consumption of the thermo-optic switch could be only 3.6 mW, and the response time of the switch could reach about 8 ms. This is a significant improvement in reducing power consumption compared with the normal Y-branched polymer thermo-optic switch.

Novel three chiral azobenzene polyurethanes: Preparation, optical properties and simulation comparisons of two different polymeric thermo-optic switches

Three different structures of chiral side-chain azobenzene polyurethane (CAPU-1), chiral graft azobenzene polyurethane (CAPU-2) and chiral bisazo polyurethane (CAPU-3) were prepared by diazo coupling reaction. The structures, thermal, mechanical properties, refractive index (n) and transmission loss of CAPU-1~3 were investigated. The Y-branch and Mach–Zehnder polymeric thermo-optic switches were simulated based on the synthesized three chiral azo polyurethanes as waveguide materials. The response time differences are owing to the different substituents and structure of the azo compound. The conclusion had potential significance to improve and develop the new digital optical and thermo-optic switch (TOS) with short response time and low driving power.

Synthesis, Thermo-Optic Properties, and Polymeric Thermo-Optic Switch Based on Novel Optically Active Polyurethane (Urea)

A novel optically active polyurethane (urea) (PUUS) was synthesized based on azo chromophore molecule, 4-(4′-nitro-phenyldiazoalkenyl)-(α-methyl)-benzylamine (NPMBS), S(-)-α-methyl benzylamine, IPDI and GE-210. The physical properties of PUUS were investigated. The refractive index (n), thermo-optic coefficient (dn/dT), transmission loss, dispersions curve and Sellmeyer coefficients of PUUS were obtained by attenuated total reflection technique, charge coupled device and Sellmeyer equation. A Y-branched switch based on thermo-optic effect in the silicon substrate was proposed and the performance of switch was simulated. The power consumption and response time of the thermo-optic switch were only 0.72 mW and 3.5 ms, respectively.

SYNTHESIS, PHYSICAL PROPERTIES AND POLYMERIC DIGITAL OPTICAL SWITCH OF AZO BENZOTHIAZOLE POLYURETHANE-UREA

An azo chromophore 4-[(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3-diamine NBDPD was synthesized with 2-amino-6-nitrobenzothiazole and m-phenylenediamine by diazo-coupling reaction. Then, NBDPD was polymerized with NJ-220 and IPDI to obtain novel azo benzothiazole polyurethane-urea (BPUU). The structure and physical properties were characterized and investigated. The refractive index and transmission loss of BPUU film were measured by attenuated total reflection technique and the CCD digital imaging devices. The polymeric digital optical switch (DOS) based on the thermo-optic effect of the BPUU was designed and simulated. The results showed that the power consumption and response time of the DOS could be only 2.3 mW and 5.0 ms, respectively.

Synthesis of Amino-Functionalized Graphene Oxide/Azobenzene Polyimide and its Simulation of Optical Switches

Abstract In this work, an amino-functionalized graphene oxide (AFGO) was synthesized by graphene oxide (GO) and ethylene diamine. A novel amino-functionalized graphene oxide/azobenzene polyimide (AFGO/ACPI) was synthesized with AFGO, azobenzene chromophore and pyromellitic dianhydride (PMDA). The structure, mechanical and thermal property of AFGO/ACPI were characterized and measured by fourier transform infrared, UV-visible spectroscopy, near-infrared spectrum, thermogravimetric analysis and differential scanning calorimetry. To obtain the refractive index of AFGO/ACPI at different temperature and wavelength (532 nm, 650 nm and 850 nm), the attenuated total reflection (ATR) method was used to measure, and thermo optic coefficients (dn/dT) were −7.22×10−4 (532 nm), −6.20×10−4 (650 nm) and −5.84×10−4 (850 nm) °C−1, respectively. The transmission loss of AFGO/ACPI thin film was surveyed using the CCD digital imaging devices and the value was 0.167 dB/cm. According to the thermo-optic effect of AFGO/ACPI film, the 1×2 Y-branch and 2×2 Mach-Zehnder optical switches were simulated. The results showed that the power consumptions of the 1×2 Y-branch and 2×2 Mach-Zehnder optical switches were only 0.63 mW and 1.45 mW. The response time was about 0.5 ms, and compared to the normal polymeric thermo-optic switch, it can improve the response time and contribute to researches of optical switches.

Fabrication of chromophore molecule-linked azo polymer as waveguide material of polymeric thermo-optic digital optical switch

A chromophore molecule-linked azo polymer as waveguide material (MCAP) of polymeric thermo-optic digital optical switch (DOS) was prepared with a chromophore molecule (ABFA), a polyether polyol and isophorone diisocyanate (IPDI). The chemical structures of ABFA monomer and azo polymer MCAP were characterized by FT-IR and UV–Visible spectroscopy. The thermal and mechanical properties of the MCAP film were investigated. The refractive index and transmission loss of MCAP film were measured at different temperatures and different laser wavelengths by an attenuated total reflection (ATR) technique and CCD digital imaging devices. A polymeric thermo-optic DOS based on the thermo-optic effect of the MCAP was designed and the performance of the switch was simulated by using the finite difference beam propagation method (FD-BPM). The experimental results showed that the power consumption of the polymeric thermo-optic switch could be only 0.64mW, while the response time of the switch could be as short as 3.0ms.

Synthesis, Optical Property, and Simulation of Thermo-Optic Switch of Novel Azopolymer

A novel azopolymer polyurethane-urea (PUU) was synthesized from chromophore molecule 4-(4-nitrophenyl-alkenyl) phenyl-1,3-diamine, polyether polyol, and isophorone diisocyanate. The structure, mechanical property, and thermal property of PUU were characterized and measured. The refractive index and transmission loss of PUU was determined using ATR technique. A Y-branch polymeric thermo-optic switch was proposed and simulated. The result showed that the power consumption of the switch could be only 2.4 mW, and the response time of the switch could reach about 4 ms. It has a significant improvement in reducing the power consumption and response time of the Y-branch polymeric thermo-optic switches.