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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • Signal-to-Noise Ratio (SNR)
  • Infinite Gain Multiple Feedback (IGMF)
  • Visible Light Communications (VLC)
  • LED
  • Trans-Impedance Amplifier (TIA)
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • University of Northumbria
  • University of Huddersfield
233 条数据
?? 中文（中国） ▾

  • 990 nm High-power High-beam-quality DFB Laser With Narrow Linewidth Controlled By Gain-coupled Effect

    摘要： High-power single-longitudinal-mode regrowth-free gain-coupled distributed feedback laser diode based on ridge waveguide with periodic current injection is achieved at 990 nm. Our device is fabricated only by standard i-line lithography with micron-scale precision, obtains an excellent performance at high injection current. A continuous-wave power of over 0.681 W is achieved at 3 A. The maximum continuous-wave power at single-longitudinal-mode operation is up to 0.303 W at 1.4 A. Narrow linewidth emission has been reached with a 3 dB spectrum width less than 1.41 pm. The high side mode suppression ratio is over 35 dB. The lateral far field divergence angle is only 15.05 °, the beam quality factor M 2 is 1.245, achieving a laterally near-diffraction-limit emission. It is more beneficial for single mode fiber coupling as pumping sources and other applications which require high beam quality at high power with easy fabrication technique.

    关键词： narrow linewidth,Single-longitudinal mode,Gain-coupled DFB,Semiconductor lasers

    更新于2025-11-28 14:24:03

  • High-power single-longitudinal-mode double-tapered gain-coupled distributed feedback semiconductor lasers based on periodic anodes defined by i-line lithography

    摘要： In this paper, we demonstrate a regrowth-free double-tapered gain-coupled distributed feedback semiconductor laser. It is designed based on periodic surface current injection to reach a high-power and single-longitudinal mode. A continuous-wave output power of over 1.2 W/facet is achieved at 4 A. High single-longitudinal-mode output power reaches up to 0.9 W/facet at 3 A at each uncoated facet. The side mode suppression ratio is nearly 30 dB at 980 nm. The 3 dB spectral width is less than 2.7 pm. The lateral far field divergence angle is only 14.5 °, the beam quality factor M2 is 1.7, achieving a near-diffraction-limit emission. Our device, produced by standard i-line lithography, enhances the output power while obtaining the pleasurable spectral and spatial properties. It has great potential in widespread commercial applications such as high efficiency pumping sources for its low-cost, easy fabrication technique and excellent performance.

    关键词： Double-tapered,Distributed feedback lasers,Gain-coupled,Semiconductor lasers

    更新于2025-11-28 14:24:03

  • Single-frequency fibre laser at 1030?nm based on gain bandwidth compression

    摘要： We demonstrate a single-frequency linear cavity fiber laser at 1030 nm with a distributed Bragg reflector cavity configuration. Despite the fact that the combination of the cavity length of the fiber laser and the reflection band of the output FBG cannot satisfy the condition of single-longitudinal mode oscillation, the single-frequency lasing is still realized by the proper temperature control of two FBGs to narrow the gain bandwidth. Under the respective temperature of two FBGs of 43.4 °C and 9 °C, the laser linewidth of around 9.6 kHz is achieved at a pump power of 113 mW. The relative noise intensity for frequencies of above 1.5 MHz is about ?140 dB Hz?1. The maximum output power of 126.2 mW is obtained with the slope efficiency of about 28%.

    关键词： fibre laser,single-frequency,gain bandwidth compression,distributed Bragg reflector

    更新于2025-11-28 14:23:57

  • Narrow-Strip 670 nm Gain-Coupled Distributed Feedback Laser Based on Periodic Anodes Fabricated by I-Line Lithography

    摘要： A narrow-strip single-longitudinal-mode gain-coupled distributed feedback semi-conductor laser with a central wavelength of approximately 670 nm is demonstrated. We fabricate a novel micro-scale regrowth-free gain-coupled grating with an island-like shape without nanoscale gratings by i-line lithography only. The maximum output power from the ?ber of the device with butter?y package is 48.1 mW at 100 mA and its slope ef?ciency is 0.79 W/A. The laser can be continuously tuned from 670.750 to 670.784 nm with a side-mode suppression ratio of over 40 dB, covering the absorptive peak of lithium atoms. Our easily fabricated devices have great potential as light sources in many applications such as lithium atom detectors.

    关键词： continuous tunability,gain-coupled,distributed-feedback,Semiconductor laser

    更新于2025-11-28 14:23:57

  • Fiber optic birefringence enhanced accelerometer based on polarized modal interferometer

    摘要： An inline fiber optic birefringence enhanced accelerometer (FOBEA) which applies one polarizer and a ten-meter high birefringence fiber wrapped on a transducer cylinder is proposed. Birefringence of polarized modes in panda polarization maintaining fiber (PMF) is enhanced by fiber coating and cylinders of different parameters. Accelerometers with copper cylinder (FOBEA-1) and polyurethane cylinder (FOBEA-2) are fabricated, the tested average sensitivities are 1.06rad/g (20-3800 Hz) and 16.97 rad/g (20-2000 Hz). The experimental results show the birefringence gain of FOBEA-1 is in good consistent with theoretical calculation of 1.07 and an additional birefringence gain of FOBEA-2 is 5.52 because the polyurethane cylinder works as fiber coating with the thickness of 1.21 mm. Temperature crosstalk is also investigated.

    关键词： Polarized modal interferometer,Fiber optic accelerometer,Sensitivity,Transducer cylinder,Birefringence gain

    更新于2025-11-28 14:23:57

  • Low-Voltage, Full-Swing InGaZnO-Based Inverters Enabled by Solution-Processed, Ultra-Thin AlxOy

    摘要： High-performance, full-swing inverters implemented with InGaZnO thin-film transistors (TFTs) have been demonstrated capable of operating at a very low voltage. The threshold voltage of the load and drive TFTs were modified through careful change of the gate dielectric anodization voltage. Both the load and drive TFTs show excellent electrical properties including a current on/off ratio > 106 and a subthreshold swing close to the theoretical limit. As a result, the inverters show high voltage gains up to 34 at a supply voltage of only 1 V as well as high noise margins > 92% of the theoretical maximum. The devices and the fabrication process might have potential applications in future wearable and disposable electronics where low cost and low power are vital.

    关键词： InGaZnO,one-volt operation,high voltage gain and noise margins,full-swing inverters

    更新于2025-11-14 17:28:48

  • Optical Characterization of Doped Thermoplastic and Thermosetting Polymer-Optical-Fibers

    摘要： The emission properties of a graded-index thermoplastic polymer optical fiber and a step-index thermosetting one, both doped with rhodamine 6G, have been studied. The work includes a detailed analysis of the amplified spontaneous emission together with a study of the optical gains and losses of the fibers. The photostability of the emission of both types of fibers has also been investigated. Comparisons between the results of both doped polymer optical fibers are presented and discussed.

    关键词： polymer optical fibers,thermoplastic fibers,rhodamine 6G,light-emitting polymers,optical gain,amplified spontaneous emission,thermosetting fibers

    更新于2025-11-14 15:30:11

  • Advancement of CMOS Transimpedance Amplifier for Optical Receiver

    摘要： Transimpedance amplifier (TIA) is an essential component of optical receivers, and this type of amplifier converts the photocurrent to a voltage signal. The overall performance of the optical receiver greatly depends on the performance of this component. Low-power, low-noise, and compact TIA has been realized in current development in CMOS technology. The high demands of an optical receiver has led to the optimization and development of the TIA designed specifications. However, the conventional CMOS TIA design is limited mainly because of its dependency on input node capacitance. In this article, the advancement of TIAs in data communication and instrumentation based on different design architectures and performances is discussed. This review will serve as a comparative study and reference for designing fully integrated CMOS TIA for future optical receivers.

    关键词： TIA,Gain,CMOS,Sensor,Optical receiver

    更新于2025-09-23 15:23:52

  • Coordinated control of MPPT and voltage regulation using single-stage high gain DC–DC converter in a grid-connected PV system

    摘要： In general, grid-connected PV system uses two stages of DC-DC converter to accomplish Maximum Power Point Tracking (MPPT) and DC voltage regulation. In order to overcome the two stage conversion, a single stage high gain DC-DC converter is presented in this paper. The operation of three switches with two different duty ratio is the main advantage of this converter to accomplish the coordinated control of MPPT and DC voltage regulation. This coordinated control also helps to provide constant DC voltage to the DC loads though the inverter is disconnected from the DC bus. A 1KW grid-connected PV system with the proposed DC-DC converter is developed and is validated using OP4500 Real-Time test platform. In addition, a decoupled control strategy with fractional order proportional-integral (FOPI) controller is implemented at the inverter end. Also, the reactive power compensation, harmonic reduction (less than 5% as per the IEEE 519 standard) and the grid power factor close to unity is obtained and the results are validated using the real-time simulator.

    关键词： Solar photovoltaics,LCL filter,Coordinated control of MPPT and voltage regulation,High gain DC-DC converter,Grid integration and power quality

    更新于2025-09-23 15:23:52

  • Application of Karpman-Maslov-Solov’ev soliton perturbation theory to systems with distributed gain or losses

    摘要： We analyze the most important ideas of the Karpman-Maslov-Solov’ev soliton perturbation theory, and based on it, we solve analytically the long-standing problem of the Schr?dinger soliton interactions in the systems with distributed losses or gain. Our analytical results do give a quite good qualitative and quantitative check of the numerical results known so far. Unexpected and nontrivial result consists in the fact that the relative soliton separation depends on the accumulated (integrated) losses or gain.

    关键词： Karpman-Maslov-Solov’ev soliton perturbation theory,Distributed losses or gain,Soliton interactions

    更新于2025-09-23 15:23:52