Mach-Zehnder Interferometer Thermo-optic Switch Research Articles

Low-power-consumption polymer Mach-Zehnder interferometer thermo-optic switch at 532 nm based on a triangular waveguide.

We designed and fabricated a Mach-Zehnder interferometer (MZI) thermo-optic switch with an inverted triangular waveguide. The inverted triangular waveguide achieves a fundamental mode in a large waveguide dimension, which can reduce the coupling loss and increase the extinction ratio. The triangular waveguide-based switch was simulated and presented higher heating efficiency and lower power consumption than that of the traditional rectangular waveguide-based switch. Compared with the traditional rectangular waveguide-based device, the power consumption of the proposed device is reduced by 60%. Spacing photobleaching was introduced to fabricate the inverted triangular waveguide and adjust the refractive index to minimize the mode number. The insertion loss of the typical fabricated device with a 2 cm length is about 7.8 dB. The device shows an extinction ratio of ∼8.1dB at 532 nm with a very low power consumption of 2.2 mW, and the switching rise time and fall time are 110 and 130 µs, respectively. The proposed single-mode waveguide and low-power-consumption optical switch have great potential applications in visible optical communication fields such as wavelength division multiplexing and mode-division multiplexing.

Preparation of a main-chain azo polyurethane-urea and its application of Y-branch and Mach–Zehnder thermo-optic switch

A novel main-chain azo polyurethane-urea (MCAPUU) was prepared with chromophore molecule 1,1′-azobisformamide (ABFA), polyether polyol (NJ-220) and isophorone diisocyanate (IPDI). The chemical structures of ABFA monomer and MCAPUU were characterized by the FT-IR and UV–Visible spectroscopy. The thermal and mechanical properties of MCAPUU film were investigated. The refractive index and transmission loss of MCAPUU film were measured at different temperature and different laser wavelength by attenuated total reflection (ATR) technique and the CCD digital imaging devices. The thermo-optic coefficients (dn/dT) of MCAPUU are −4.5429 × 10−4 °C−1 (532 nm), −5.7943 × 10−4 °C−1 (650 nm) and −6.6057 × 10−4 °C−1 (850 nm), respectively. A Y-branch switch and Mach–Zehnder interferometer (MZI) thermo-optic switches based on thermo-optic effect were proposed and the performances of switches were simulated. The results showed that the power consumption of the Y-branch thermo-optic switch is only 0.74 mW. The rising and falling times of Y-branch and MZI switches are 12.0 and 1.8 ms, respectively. The results indicate that the prepared MCAPUU has high potential for the applications of the Y-branch digital optical switch (DOS), MZI thermo-optic switch, directional coupler (DC) switch and optical modulators.

Synthesis, physical properties and simulation of thermo-optic switch based on azo benzothiazole heterocyclic polymer

A chromophore molecule 4-[(benzothiazole-2-yl)diazenyl]phenyl-1,3-diamine (BTPD) was prepared with 2-amino benzothiazole and m-phenylenediamine by diazo-coupling reaction. Then, the BTPD was polymerized with polyether polyol (NJ-220) and isophorone diisocyanate (IPDI) to obtain novel azo benzothiazole polyurethane-urea (BTPUU). The chemical structures of BTPD and BTPUU were characterized by FT-IR and UV–visible spectroscopy. The thermal and mechanical properties of BTPUU film were investigated. The refractive index and transmission loss of BTPUU film were measured at different temperatures and different laser wavelengths (532nm, 650nm and 850nm) by an attenuated total reflection (ATR) technique and CCD digital imaging devices. The thermo-optic coefficients of BTPUU are −4.7086×10−4°C−1 (532nm), −6.5257×10−4°C−1 (650nm) and −5.1029×10−4°C−1 (850nm), respectively. A Y-branch switch and Mach–Zehnder interferometer (MZI) thermo-optic switches based on thermo-optic effect were proposed and the performances of the switches were simulated, respectively. The results show that the power consumption of the Y-branch thermo-optic switch is only 3.28mW. The response times of Y-branch and MZI switches are 8.0ms and 2.0ms, respectively. The results indicate that the prepared BTPUU has high potential for the applications of the Y-branch digital optical switch (DOS), MZI thermo-optic switch, directional coupler (DC) switch and optical modulators.

Preparation and thermo-optic switch properties based on chiral azobenzene-containing polyurethane

A chiral azo chromophore compound 4-(4′-nitro-phenyl-diazenyl)-phenyl-1,2-propanediol ether (NPDPPE) was prepared with p-nitroaniline, phenol and R(−)-3-chloro-1,2-propanediol by the diazo-coupling reaction. Then, the chromophore molecule NPDPPE was polymerized with isophorone diisocyanate (IPDI) to obtain novel chiral azobenzene-containing polyurethane (CACPU). The chemical structures of chromophore molecule and CACPU were characterized by the FT-IR and UV–visible spectroscopy. The physical properties (thermal conductivity, thermal diffusion coefficient, and specific heat capacity) and mechanical properties (tensile strength, elongation at break and hardness) of CACPU thin films were measured. The refractive index and thermo-optic (TO) coefficient (dn/dT) of CACPU thin film was investigated for TE (transversal electric) polarizations by using an attenuated total reflection (ATR) configuration at the wavelengths of 532, 650 and 850nm. The transmission loss of film was measured using the charge coupled device (CCD) digital imaging devices. A Y-branch switch and Mach–Zehnder interferometer (MZI) thermo-optic switches based on thermo-optic effect were proposed and the performances of switches were simulated. The results showed that the power consumption of the Y-branch thermo-optic switch was only 3.28mW. The rising and falling times of Y-branch and MZI switches were 12.0ms and 2.0ms, respectively. The conclusion has potential significance to improve and develop new Y-branch digital optical switch (DOS), MZI thermo-optic switch, directional coupler (DC) switch and optical modulators.

Driving-Noise-Tolerant Broadband Polymer/Silica Hybrid Thermo-Optic Switch with Low Power Consumption

A polymer/silica hybrid Mach–Zehnder interferometer thermo-optic switch is experimentally demonstrated. The switch exhibits low power consumption of 7.8 mW, high extinction ratio of 32.6 dB, and short rise and fall times of 107 and 71 μs, respectively. The output spectrum is 50 nm (1,520–1,570 nm), with the extinction ratio level of over 18 dB. The driving-noise tolerance of this device was experimentally investigated by imposing a generated tunable noise on the pure driving signal. The device reveals a voltage-noise budget as high as 1.1 Vpp relative to a driving voltage of 3.0 Vpp for obtaining higher than a 10-dB extinction ratio.

Submilliwatt thermo-optic switches using free-standing silicon-on-insulator strip waveguides

A low power Mach-Zehnder interferometer thermo-optic switch using free-standing silicon-on-insulator strip waveguides is demonstrated. The air gap provides thermal isolation between the waveguide interferometer arms and the underlying silicon substrate. The highly confined optical modes of the strip waveguides enable miniature heated cross-sections. The heating efficiency from on-chip resistive heaters is enhanced. Measurements of fabricated devices using 100 microm arm lengths at 1550 nm wavelength result in a switching power of 540 microW, a 10% - 90% switching rise time of 141 micros, and an extinction ratio of 25 dB.

다중모드 간섭현상을 이용한 1×16 마하젠더 스위치 개발

본 논문에서는 실리카 기반의 다중모드 간섭기를 이용하여 적은 초과손실을 갖는 <TEX>$1{\times}16$</TEX> 마하젠더 스위치에 대한 설계 및 측정결과에 대하여 논하였다. 제작된 <TEX>$1{\times}16$</TEX> 마하젠더 스위치는 마하젠더 간섭계(Mach-Zehnder Interferometer, MZI) 구조를 갖는 <TEX>$2{\times}2$</TEX> 열광학스위치를 단위소자로 하였으며, 15개의 단위소자를 이용하여 4단(stage)으로 구성하였다. 먼저 광분배기와 <TEX>$2{\times}2$</TEX> MZI 열광학 스위치등의 개별적인 특성을 파악하였고, 그 결과를 전체 소자의 설계에 적용함으로써 보다 좋은 성능을 얻을 수 있었다. 제작된 다중모드 간섭기를 이용한 MZI 구조의 단위스위치 당 초과손실은 최소 -0.5dB로 측정되었다. A <TEX>$1{\times}16$</TEX> thermo-optic switch with small excess loss using multimode interference(MMI) couplers is designed, fabricated, and measured. This paper introduces the proposed <TEX>$1{\times}16$</TEX> thermo-optic switch, and discusses the measurement results. The <TEX>$1{\times}16$</TEX> thermo-optic switch is farmed as 4-stage which consists of 15 unit devices. The unit devices are the <TEX>$2{\times}2$</TEX> thermo-optic switches with Mach-Zehnder interferometer(MZI) structure. The characteristics of the <TEX>$1{\times}16$</TEX> thermo-optic switch depends strongly on each unit device. The unit deviceconsists of two 3-dB general interference MMI couplers and two single mode waveguide arms as a phase shifter. First of all, the 3-dB optical splitter and <TEX>$2{\times}2$</TEX> MZI thermo-optic switch have been tested to confirm the characteristics of the unit devices of the <TEX>$1{\times}16$</TEX> MZI thermo-optic switch. Using the measurement results of the unit devices, the <TEX>$1{\times}16$</TEX> MZI thermo-optic switch can be produced with better characteristics. The resultant structure of the MMI coupler with the optical light source of wavelength of 1550nm for the <TEX>$1{\times}16$</TEX> thermo-optic switch is that the width and the optimized length are <TEX>$25{\mu}m\;and\;1580{\mu}m$</TEX>, respectively. The smallest excess loss fur the unit device is -0.5dB and the average excess loss is -0.7dB.