A novel flow through optical fiber biosensor for glucose based on luminol electrochemiluminescence

A novel flow injection optical fiber biosensor for glucose based on luminol electrochemiluminescence (ECL) is presented. The sol-gel method is introduced to immobilize glucose oxidase (GOD) on the surface of a glassy carbon electrode. After optimization of the working conditions, glucose could be quantitated in the concentration ranges between 50 muM and 10 mM with a detection limit of around 26 muM. Signal reproducibility was about 3.62% relative standard deviation for 11 replicated measurements of 0.1 mM glucose. The ECL biosensor also showed good selectivity and operational stability. The proposed method can be applied to determination of glucose in soft drink samples.

Electrochemiluminescent determination of glucose with a sol-gel derived ceramic-carbon composite electrode as a renewable optical fiber biosensor

A sol-gel derived ceramic-carbon composite electrode is used for fabrication of a new type of optical fiber biosensor based on luminol electrochemiluminescence (ECL). The electrode consists of graphite powder impregnated with glucose oxidase in a silicate network. In this configuration, the immobilized enzyme oxidizes glucose to liberate hydrogen peroxide and graphite powder provides percolation conductivity for triggering the ECL between luminol and the liberated hydrogen peroxide. Both of the reactions occur simultaneously on the surface of the composite electrode, thereby the response of the biosensor is very fast. The peak intensity was achieved within only 20 s after glucose injection. In addition, the electrode could be renewed by a simple mechanical polishing step in case of contamination or fouling. The linear range extends from 0.01 to 10 mM for glucose and the detection limit is about 8.16 muM. The renewal repeatability and stability of the biosensor are also investigated in detail.

A chemiluminescence optical fiber glucose biosensor based on co-immobilizing glucose oxidase and horseradish peroxidase in a sol-gel film

An optical fiber bienzyme sensor based on the luminol chemiluminescent reaction was developed and demonstrated to be sensitive to glucose. Glucose oxidase (GOD) and horseradish peroxidase (HRP) were co-immobilized by microencapsulation in a sol-gel film derived from tetraethyl orthosilicate(TEOS). The calibration plots for glucose were established by the optical fiber glucose sensor fabricated by attaching the bienzyme silica gel onto the glass window of the fiber bundle. The linear range was 0.2-2 mmol/L and the detection limit was approximately 0.12 mmol/L. The relative standard deviation was 5.3% (n = 6). The proposed biosensor was applied to glucose assay in ofloxacin injection successfully.

毫米波副载波光纤通信技术的研究进展

综述了用于下一代移动通信的光纤毫米波副载波通信技术（ROF）的研究进展。介绍了系统的基本构想和涉及的关键技术。着重介绍几种毫米波副载波光发射器以及有关光学技术的新进展，包括外调制器方法、射频上转换法、光学外差法、毫米波调制光脉冲发生器等；简要介绍了ROF接收技术、系统技术和有关应用的研究动向。

Integratable and High Speed Complex-Coupled MQW-DFB Lasers Fabricated on Semi-Insulating Substrates

A novel integratable and high speed InGaAsP multi-quantum well (MQW) complex-coupled distributed feedback (DFB) laser is successfully fabricated on a semi-insulating substrate. The fabricated ridge DFB laser exhibits a threshold current of 26 mA, a slope efficiency of 0.14 W.A(-1) and a side mode suppression ratio of 40 dB together with a 3 dB bandwidth of more than 8 GHz. The device is suitable for 10 Gbit/s optical fiber communication.

Wavelength tunable distributed Bragg reflector laser integrated with electro-absorption modulator by a combined method of selective area growth and quantum well intermixing - art. no. 68240N

Wavelength tunable electro-absorption modulated distributed Bragg reflector lasers (TEMLs) are promising light source in dense wavelength division multiplexing (DWDM) optical fiber communication system due to high modulation speed, small chirp, low drive voltage, compactness and fast wavelength tuning ability. Thus, increased the transmission capacity, the functionality and the flexibility are provided. Materials with bandgap difference as large as 250nm have been integrated on the same wafer by a combined technique of selective area growth (SAG) and quantum well intermixing (QWI), which supplies a flexible and controllable platform for the need of photonic integrated circuits (PIC). A TEML has been fabricated by this technique for the first time. The component has superior characteristics as following: threshold current of 37mA, output power of 3.5mW at 100mA injection and 0V modulator bias voltage, extinction ratio of more than 20 dB with modulator reverse voltage from 0V to 2V when coupled into a single mode fiber, and wavelength tuning range of 4.4nm covering 6 100-GHz WDM channels. A clearly open eye diagram is observed when the integrated EAM is driven with a 10-Gb/s electrical NRZ signal. A good transmission characteristic is exhibited with power penalties less than 2.2 dB at a bit error ratio (BER) of 10(-10) after 44.4 km standard fiber transmission.

Uncooled Submarine Pump Laser Module at 980 nm

We present a new generation 980 nm submarine pump module that consists of a hermitically sealed 8-pin ceramic MiniDIL package without thermo-electric cooler.

An Improved Selective Area Growth Method in Fabrication of Electroabsorption Modulated Laser

An improved selective area growth (SAG) method is proposed to better the fabrication and performance of the Electroabsorption modulated laser The typical threshold current of the EML is 18mA, and the output power is 5.6mW at EAM facet.

Dispersion characteristics of nanometer-scaled silicon rib waveguides

We investigate the dispersion properties of nanometer-scaled silicon waveguides with channel and rib cross section around the optical fiber communication wavelength and systematically study their relationship with the key structural parameters of the waveguide. The simulation results show that the introduction of an extra degree of freedom in the rib depth enables the rib waveguide more flexible in engineering the group velocity dispersion (GVD) compared with the channel waveguide. Besides, we get the structural parameters of the waveguides that can realize zero-GVD at 1550 nm.

Single ridge waveguide electroabsorption modulated DFB laser for 2.5Gb/s transmission

In this paper we proposed a single ridge waveguide electroabsorption modulated distributed feedback laser (EML) for long-haul high-speed optical fiber communication system. This EML was successfully fabricated by two step metal organic vapor phase epitaxy (MOVPE) including selective area growth (SAG) and helium partially implantation. No obvious changes of the threshold current (< 0.2 mA), extinction ratio (< 0.1 dB), output power (< 0.2 dBm) and isolation resistance were achieved in the preliminary aging test. With 2.5 Gb/s NRZ modulation, no power penalty was observed after the optical signal was transmitted through 280 Km normal single mode fiber.

Long-wavelength SiGe/Si MQW resonant-cavity-enhanced photodiodes (RCE-PD)

Si1-xGex/Si optoelectronic devices are promising for the monolithic integration with silicon-based microelectronics. SiGe/Si MQW RCE-PD (Resonant-Cavity-Enhanced photodiodes) with different structures were investigated in this work. Design and fabrication of top- and bottom-incident RCE-PD, such as growth of SiGe MQW (Multiple Quantum Wells) on Si and SOI (Si on insulator) wafers, bonding between SiGe epitaxial wafer and SOR (Surface Optical Reflector) consisting Of SiO2/Si DBR (Distributed Bragg Reflector) films on Si, and performances of RCE-PD, were presented. The responsivity of 44mA/W at 1.314 mum and the FWHM of 6nm were obtained at bias of 10V. The highest external quantum efficiency measured in the investigation is 4.2%.

光纤在煤矿救援探测机器人中的应用

应用于煤矿井下的煤矿救援探测机器人需要与地面监控指挥中心传输命令、井下环境状态等信息,这种通信具有远程、大容量和实时性等特点。根据这些特点,设计了一种光纤通信系统。

High efficiency fiber to waveguide optical coupler in silicon-on-insulator-based slot waveguides - art. no. 68310R

We propose a novel optical fiber-to-waveguide coupler for integrated optical circuits. The proper materials and structural parameters of the coupler, which is based on a slot waveguide, are carefully analyzed using a full-vectorial three dimensional mode solver. Because the effective refractive index of the mode in a silicon-on-insulator-based slot waveguide can be extremely close to that of the fiber, a highly efficient fiber-to-waveguide coupling application can be realized. For a TE-like mode, the calculated minimum mismatch loss is about 1.8dB at 1550nm, and the mode conversion loss can be less than 0.5dB. The discussion of the present state-of-the-art is also involved. The proposed coupler can be used in chip-to-chip communication.

Performance analysis of bit error rate for free space optical communication with tip-tilt compensation based on gamma-gamma distribution

In this paper, the gamma-gamma probability distribution is used to model turbulent channels. The bit error rate (BER) performance of free space optical (FSO) communication systems employing on-off keying (OOK) or subcarrier binary phase-shift keying (BPSK) modulation format is derived. A tip-tilt adaptive optics system is also incorporated with a FSO system using the above modulation formats. The tip-tilt compensation can alleviate effects of atmospheric turbulence and thereby improve the BER performance. The improvement is different for different turbulence strengths and modulation formats. In addition, the BER performance of communication systems employing subcarrier BPSK modulation is much better than that of compatible systems employing OOK modulation with or without tip-tilt compensation.