ESD sensitivity of AlGaAs and InGaAsP based Fabry–Perot laser diodes

The sensitivity to electrostatic discharges of Fabry–Perot laser diodes with InGaAsP as active layer material has been tested and compared to Fabry–Perot lasers based on AlGaAs as active layer material. In the case of the forward-bias ESD pulses we observed a substantially lower degradation threshold voltage for the AlGaAs type lasers as compared to the InGaAsP type lasers. A detailed analysis of the optical and electrical parameters before and after ESD test with particular emphasis on the characteristic temperature and optical emission spectra changes has been done. Effective suppression of the optical emission on a ns-time scale due to device heating during the forward-bias ESD pulses has been evidenced by monitoring the light emission during ESD pulses.     

Characterization of Fabry–Perot laser diodes injection locked by spectrum sliced ASE noise in WDM-PON

We experimentally evaluate the performance of Fabry–Perot laser diodes (FPLDs) injection locked by spectrum sliced amplified spontaneous emission (ASE) noise for transmission at 1.25 Gb/s. We characterize the injection locked FPLDs in terms of front-facet reflectivity, operation temperature, bias current and injection locked mode location. Experiment results show that the FPLD performance is strongly dependent on the front-facet reflectivity. Therefore a reasonable range of front-facet reflectivity for FPLDs is recommended. Operating the lasers at low temperature has better receiver sensitivity, while operating at high temperature has slightly broader operation range for injected ASE power. There is an optimal bias for a given injection power and the operation range for bias current is increased for higher injection power. Injection locked mode location also affects the performance of FPLDs.     

一种Fabry—Perot谐振器天线

设计了一种Fabry—Perot谐振器天线,相对于微带贴片天线而言具有较宽的频带和较高的增益。仿真结果表明．该天线的实用频带的相对带宽达到了7.7％,增益最大值达到了17．83dBi,能对电磁波起到较好的聚焦作用,并且在一定程度上改善了旁瓣和后瓣。     

Distributed Fabry——Perot Measurement System

The theoretic analysis indicates that if the lengths of the cascaded and paralleled Fabry-Perot sensors are properly selected, the crosstalk can be well restricted.And the experiment simulation results agree with that of the theoretic analysis.     

光波导Fabry—Perot型电光模数转换器

研制成以ＬｉＮｂＯ３质子交换光波导Ｆ－Ｐ型干涉调制器阵列为核心结构的电光模数转换器。简述了Ｆ－Ｐ型模数转换器的原理，报导了实验样品的设计参数，制备工艺，测量装置和初步结果。     

Study on Fabry–Perot cavity consisting of two chirped fiber Bragg gratings

Combined the effective mirror surface model with the transfer matrix method, a detailed theoretical and numerical study on Fabry–Perot cavity consisting of two chirped fiber Bragg gratings is investigated. Results demonstrate that transmission responses of the Fabry–Perot cavity can be adjusted by changing the cascading sequences of the two gratings. When the two gratings are connected in the direction of same chirping, approximately uniform resonance and group delay are exhibited. However, some distinctive non-uniformity of the neighboring resonance peaks intervals is shown if the two gratings are cascaded in the opposite chirping sequences. In addition, for the Fabry–Perot cavity constructed by chirped-fiber-Bragg-gratings with different amplitudes or bandwidths, efficient resonances are achieved only in the common reflection range.     

Grating Angular－movement Transducer Using a Fabry－Perot Structure

ＧｒａｔｉｎｇＡｎｇｕｌａｒ－ｍｏｖｅｍｅｎｔＴｒａｎｓｄｕｃｅｒＵｓｉｎｇａＦａｂｒｙ－ＰｅｒｏｔＳｔｒｕｃｔｕｒｅ①ＬＩＺｈｉｑｕａｎ（ＹａｎｓｈａｎＵｎｉｖｅｒｓｉｔｙ，Ｑｉｎｇｈｕａｎｇｄａｏ０６６００４，ＣＨＮ）Ａｂｓｔｒａｃｔ：Ａｎｏｖｅ...     

Grating Angular—movement Transducer Using a Fabry—Perot Structure

A novel grating angular-movement transducer using a multiplex Fab-ry-Perot interference technology has been deveoped.The Fabry-Perot interferometer(FPI) has been tranditionally used to examine either small spectral ranges or reatively simple spectra.Recently,however,the studies have shown that the FPI can be competi-tive with the Michelson interferometer over extended spectral ranges.A relatively new FPI is deseribed based on two gratings.     

Multichannel Microwave Filtration with Dipole and Chiral Elements in a Meta-Interferometer with a Fabry–Perot Resonator

Journal of Communications Technology and Electronics - In this paper, a new application of dipole and chiral elements and structures based on them as one of the reflectors of a Fabry–Perot...     

Strong fiber Bragg grating based asymmetric Fabry–Perot sensor system with multiple reflections for high sensitivity enhancement

A fiber Bragg grating based (FBG-based) Fabry–Perot (FP) sensor system utilizing multiple reflections between two strong FBGs with different reflectiveties to enhance the sensitivity is proposed. The different interference signals are obtained by using different multiple-path-matched Michelson interferometers (MIs). The system is lighted by the ultra-narrow line width erbium-doped fiber ring laser and the signal is demodulated by phase-generated carrier (PGC) scheme. The method to choose the optimal parameters of the FBG-based asymmetric FP sensor and the different matching MIs is analyzed. The experimental results show that each matching MI can steadily enhance the sensitivity of the demodulated signal in the bandwidth of 80–8000 Hz. The sensitivity of the system can be enhanced about 19.1 dB when the light reflects nine times between the two FBGs. Further more, this system can be used to extend the dynamic range and the effective working bandwidth and so on.     

Photoelastic Fabry－Perot Optical Modulator Based on a Silicon－on－Insulator Structure

ＰｈｏｔｏｅｌａｓｔｉｃＦａｂｒｙ－ＰｅｒｏｔＯｐｔｉｃａｌＭｏｄｕｌａｔｏｒＢａｓｅｄｏｎａＳｉｌｉｃｏｎ－ｏｎ－ＩｎｓｕｌａｔｏｒＳｔｒｕｃｔｕｒｅ￥ＹＵＬｉｓｈｅｎ（ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００８７１，ＣＨＮ）ＧＵＡ...     

2 μm noise-like mode-locked fiber laser based on nonlinear optical loop mirror

We report a Tm-doped noise-like mode-locked (NLML) pulsed fiber laser with a compact linear cavity which consists of dual nonlinear optical loop mirrors (NOLMs). The design of dual-NOLM shows both exceptional compactness in construction and distinct flexibility. In this laser, mode-locking can be realized through the nonlinear optical loop mirror technique. Stable noise-like mode-locked pulses with spectral bandwidth of 29.18 nm and pulse energy of 46 nJ are generated at a central wavelength of 1 999.7 nm. Our results indicate that such a simple and inexpensive structure can pave the way for the development of generating supercontinuum with desirable performance.     

带单模尾纤的GRIN透镜型Fabry—Perot腔可调谐光滤波器

本文报道１．５５μｍ及１．３１μｍ波段带单模尾纤的ＧＲＩＮ透镜型Ｆａｂｒｙ—Ｐｅｒｏｔ腔可调谐光滤波器的研制。器件在较宽的自由谱区内有良好的滤光特性。文中介绍了器件的工作原理及其结构设计和制作关键，并给出了用光谱分析方法测得的结果。     

Photoelastic Fabry—Perot Optical Modulator Based on a Silicon—on—Insulator Structure

A simple photoelastic optical modulator with a Fabry-Perot cavity based on the silicon-on-insulator system was fabricated. A 50 % modulation depth has been obtained at current density of about 1. 5 x 103 A/cm2. The insertion loss was about 15 dB.     

3.1–10.6 GHz ultra-wideband LNA design using dual-resonant broadband matching technique

This paper presents an ultra-wideband low noise amplifier design using the dual-resonant broadband matching technique. The proposed LNA achieves a 10.2 dB gain with ±0.9 dB gain flatness over a frequency range of 3.1–10.6 GHz and a ?3-dB bandwidth of 2.4–11.6 GHz. The measured noise figure ranges from 3.2 to 4.7 dB over 3.1–10.6 GHz. At 6.5 GHz, the measured IIP3 and input-referred P1dB are +6 dBm and ?5 dBm, respectively. The proposed LNA occupies an active chip area of 0.56 mm² in a TSMC 0.18 μm RF-CMOS process and consumes 16 mW from a 1.8 V supply.     

应用Fabry—Perot标准具的相干识别型机载激光报警装置的研究

详细介绍了应用阶式法布里－珀罗标准具的机载激光报警装置的原理和结构，讨论了其中的技术难点及其解决方案。     

Decoder side Wyner–Ziv frame estimation using Chebyshev polynomial-based FLANN technique for distributed video coding

Multidimensional Systems and Signal Processing - In this paper, a Chebyshev polynomial-based functional link artificial neural network (CFLANN) technique for Wyner–Ziv (WZ) frame estimation...     

Synthesis of TiO2 thin films with highly efficient surfaces using a sol–gel technique

Three different strong acid catalysts were used in a simple sol–gel synthesis to produce TiO₂ thin films with increased homogeneity and enhanced photocatalytic activity on their mesoporous surfaces. Various techniques were used to characterize the samples, including UV–visible spectrophotometry, X-ray diffraction, micro-Raman spectrometry, photobleaching, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy. The band gaps varied from 3.73 to 3.75 eV and the transmittance was >80%. An anatase phase was obtained in all the samples and the crystal size varied from 20 to 45 nm as a function of the annealing temperature. The increase in the efficiency of the surface of the TiO₂ thin films was evaluated by photodegradation of methylene blue in water. The results showed that the acid catalysts used in the synthesis had an important effect on the morphology and photocatalytic activity of the thin films, resulting in more efficient surfaces. Synthesis with hydrofluoric acid produced thin films with a homogenous mesoporous structure and improved the photodegradation of the methylene blue dye to 92% in 2.5 h.     

2.04 μm harmonic noise-like pulses generation from a mode-locked fiber laser based on nonlinear polarization rotation

We report the generation of harmonic noise-like mode-locked pulses in a thulium-doped fiber laser. In this laser, mode-locking can be realized through the nonlinear polarization rotation(NPR) technique. The ring cavity configuration uses 5 m of a Tm-doped dual-cladding fiber, as a gain medium, pumped by a 793 nm diode laser. The cavity uses a couple of polarization controllers(PCs) and polarization-dependent isolator to form a nonlinear polarization-rotating saturable absorber. By carefully adjusting of the PCs, the laser generates noise-like mode-locked pulses at the 2.04 μm band. With the increase of the pump power, the laser generates harmonics of the mode-locking fundamental repetition frequency of 6.88 MHz, from which we can obtain the second harmonic in a controlled mode. The obtained results may be useful for enhancing the understanding of the mechanism and characteristics of noise-like pulse at the 2 μm band.     

Single channel source separation using time–frequency non-negative matrix factorization and sigmoid base normalization deep neural networks

Multidimensional Systems and Signal Processing - Conventional single channel speech separation has two long-standing issues. The first issue, over-smoothing, is addressed, and estimated signals are...