分布反馈激光二极管调制特性及线宽测量

本文介绍了利用光谱分析测量DFB LD调制特性的方法及装置。介绍了测量装置光路部分和电路部分的技术要点。对DFB LD的实测说明:注入DFB LD电流的变化不会引起注入载流子密度明显变化,进而不会由此引起光频率的变化。这种测量方法可方便而准确地测量使用DFB LD的光端机的直接光强调制深度。     

A method to determine the above-threshold stability of distributedfeedback semiconductor laser diodes

An analysis of the above-threshold stability of distributed feedback (DFB) semiconductor laser diodes (LD's) is presented. It is based on a numerical model which takes into account effects of spatial hole burning (SHB) and the nonlinear gain coefficient. In the analysis, the Newton-Raphson (NR) technique has not been used, and no functional derivative is required. Taking into account the presence of another nonlasing mode, the single-mode stability of the DFB laser diodes is determined. The proposed model does not depend on any particular DFB structure, and hence can be applied to various DFB LD structures. Numerical results are presented for a three-phase-shift (3PS) DFB LD     

采用纳米压印技术制作DWDM激光器的研究

 适合DWDM系统应用的高性能DFB半导体激光器是现代光通信系统中发射机的核心光电子器件,光栅的设计和制作是决定器件性能的关键因素之一。目前,基于MOCVD设备的材料外延技术趋于稳定,高速器件封装技术也已经成熟,满足DWDM需求的DFB光栅的加工渐渐成为进一步降低成本的一个瓶颈。本文利用纳米压印技术制作DFB激光器光栅。结果表明,利用纳米压印技术制作出来的DFB激光器性能不逊于用EBL直接制作出的高性能激光器,不仅可以满足DWDM系统的要求,而且还具有生产效率高、成本低的优点。     

A two-step laterally tapered 1.55-/spl mu/m SSC DFB laser fabricated by using a nonselective grating process

We demonstrate a two-step laterally tapered 1.55-/spl mu/m spot size converter distributed feedback laser diode (SSC DFB LD) having a planar buried heterostructure-type active waveguide and a ridge-type passive waveguide fabricated by using a nonselective grating process. Unlike conventional SSC DFB LDs, where a selective grating is employed, this SSC DFB LD employed a nonselective grating over the entire device region in order to make its fabrication much simpler than that of the conventional SSC DFB LDs. The two-step laterally tapered SSC is effective in removing an unwanted wavelength peak originating from the SSC section having a multiquantum well and a grating under it. The fabricated SSC DFB LD operates at 1.553-/spl mu/m wavelength and shows a far field pattern in horizontal and vertical directions of 13.4/spl deg/ and 19.5/spl deg/, respectively.     

Consideration on influence of directly modulated DFB LD spectralspread and fiber dispersion in multigigabit-per-second long-spanoptical-fiber transmission systems

The relation between optical-fiber dispersion and directly modulated distributed-feedback laser diode (DFB LD) spectral spread in multigigabit-per-second long-span transmission systems is discussed. It is observed that two peak spectra at the leading edge of the pulse induce spectral spread in directly modulated DFB LDs. Specifications for the difference between the DFB LD oscillation wavelength and the optical-fiber zero-dispersion wavelength in a multigigabit-per-second long-span transmission system, considering these two peak spectra, are predicted. Experimental confirmation was provided by 2-Gb/s-140-km and 5-Gb/s-100-km transmission experiments, using 1.5-μm zero-dispersion shifted optical fiber     

Two-step laterally tapered spot-size converter 1.55-/spl mu/m DFB laser diode having a high slope efficiency

We demonstrate a two-step lateral tapered 1.55-/spl mu/m spot-size converter distributed feedback laser diode (SSC DFB LD) having slope efficiencies as high as 0.457 and 0.319 mW/mA measured at 25 /spl deg/C and 85 /spl deg/C, respectively. The SSC DFB LD fabricated by using a nonselective grating process has a double core waveguide structure including a planar buried heterostructure type active waveguide and a ridge type passive waveguide. The fabricated SSC DFB LD operates at 1.553-/spl mu/m wavelength and shows a far-field pattern in horizontal and vertical directions of 7.3/spl deg/ and 11.6/spl deg/, respectively.     

Tunable optical-wavelength conversion using anoptically-triggerable multielectrode distributed feedback laser diode

Tunable optical-wavelength conversion with tunability greater than 5 Å using a multielectrode distributed-feedback laser diode (DFB LD) with a saturable absorber is discussed. This device is not dependent on input polarization and can operate at up to 500 MHz. Preliminary results of an optical switching experiment using the tunable wavelength converter and optical narrowband filter with a DFB LD amplifier are also reported     

基于1665 nm激光器测量甲烷气体浓度的研究

介绍了一种以1665 nm分布反馈(DFB)激光器为光源,使用双光路差分吸收光谱技术(DAS)测量甲烷浓度的检测系统。双光路差分吸收光谱技术能有效抑制由于光源光强变化、探测器零点漂移等因素所引起的测量的不准确。文中对这种检测方法进行了理论和实验分析,系统的最小探测浓度为100×10-6,响应时间约为14 s。     

光纤延时自外差法测量DFB型LD温度调谐的瞬态特性

以马赫-曾德干涉仪(MZI)原理为基础搭建了臂长差为3km的光纤延时自外差(FOSHI)测量系统,测量了1 582nm分布反馈型(DFB)二极管激光器(LDs)在温度调谐下输出的瞬态特性,包括LDs输出波长及线宽。结果表明,DFB LDs输出光波长随调谐温度呈线性关系,通过对光电流功率谱密度函数的洛伦兹线型拟合得到LDs的线宽为3.24MHz,与3MHz理论值相近。     

Precise wavelength control for DFB laser diodes by novel corrugation delineation method

Precise wavelength control of a multiple-wavelength DFB InGaAsP strained MQW laser-diode (LD) array was achieved using weighted-dose allocation variable-pitch EB-lithography (WAVE) and highly uniform MOVPE. Multiple-wavelength 1.3 /spl mu/m /spl lambda//4-shifted DFB LD arrays with wavelength spacing of 2.0 nm were successfully demonstrated. The standard deviation of the wavelength was as low as 0.37 nm over 2-in wafers.     

10 Gbit/s NRZ global transmission using optically amplifiedelectronic regeneration

10 Gbit/s NRZ error-free fibre transmission over distances exceeding 400000 km is demonstrated using an optically amplified regenerator with a 160 km span. Direct modulation of a DFB laser raises the stimulated Brillouin scattering power threshold while maintaining system simplicity and robustness     

Continuous-wave frequency synthesis of a laser diode based ondiscrete-time negative frequency feedback. I. Experiment

The absolute frequency synthesis of a distributed-feedback (DFB) laser diode (LD) is demonstrated by use of a loss-compensated optical ring circuit with a frequency shifter and a frequency-stabilized master laser system containing an acetylene (¹³C₂H₂ ) absorption cell. A lightwave from the master laser is modulated into a pulse and circulated around the ring to shift its frequency in the 0~100 GHz range. A continuous-wave from the DFB LD is mixed with a recirculated pulse with a desirable reference frequency, and their beat frequency is counted in order to obtain the error signal. The absolute frequency of the DFB LD is locked to the reference frequency based on discrete-time negative frequency feedback control for the injection current. The accuracy of the absolute frequency was experimentally confirmed to be within a few MHz for an averaging time of 1 s and an operation time of 1 hour     

吸收光栅增益耦合DFB—LD电路模型

本文以激光器单模速率方程为基础,针对ＤＦＢ－ＬＤ推导了光子寿命与激光器内部损耗及端面出射损耗的关系,以及端面出射光功率与平均光子密度的关系,给出吸收光栅增益耦合ＤＦＢＬＤ电路模型,用该模型研究了ＡＧ－ＧＣ－ＤＦＢ－ＬＤ的自脉动效应及影响自脉动幅度和频率的主要因素。     

Monolithic Integration of a Waveguide Optical Isolator With a Distributed Feedback Laser Diode in the 1.5- μm Wavelength Range

We present first monolithic integration of a waveguide optical isolator with a distributed feedback laser diode (DFB LD) in the 1.5-mum wavelength range. The integrated devices are composed of 0.25-mm-long index-coupled DFB LDs and 0.75-mm-long semiconductor active waveguide optical isolators. The semiconductor active waveguide optical isolators are based on the nonreciprocal loss in the semiconductor optical amplifier (SOA) waveguides with ferromagnetic metals (Fe). The fabrication process consists of two steps of metal-organic vapor phase epitaxy to grow the DFB LD/SOA layer structures, one dry-etching process for the waveguide stripe formation, and three steps of electron-beam evaporation for the electrodes and ferromagnetic metals deposition. They showed single-mode emission at 1543.8nm and 4-dB optical isolation under a magnetic field of 0.1 T.     

DFB LD在光声气体检测系统中的应用研究

针对选用分布反馈激光二极管(DFB LD)作为激励光源的光声气体检测系统,首先分析了温度和注入电流对激光稳定性(包括激射波长和输出光功率)的影响.然后提出了一种蝶形封装的DFB LD在光声甲烷检测系统中的应用方案.实验结果表明,该方案的温控系统和波长调制驱动模式可以产生稳定可靠的光声信号,具有一定的参考价值.最后根据现...     

Full-duplex radio-on-fiber transport systems based on main and multiple side modes injection-locked DFB laser diode

A full duplex radio-on-fiber (ROF) transport system based on main and multiple side modes injection-locked distributed feedback laser diode (DFB LD) is proposed and experimentally investigated. DFB LD is successfully injection-locked not only in the main mode but also in other side modes. A data signal of 70 Mbps/10 GHz (WiMAX) signal is transmitted over long-haul single-mode fiber (SMF) transmission. Good bit error rate (BER) performances were achieved for both down-link and up-link transmissions in our proposed full-duplex ROF transport systems.     

A two-step etching technique for silica terraces in the PLC hybrid integration

Two-step etching, after the full processes of a silica waveguide, was performed to fabricate a silica-terraced planar lightwave circuit platform for the hybrid integration of optoelectronic devices. Spot-size converted distributed feedback laser diodes (SSC DFB LDs) were flip-chip bonded on silica terraces with the height accuracy of less than 1 /spl mu/m, and the resultant coupling loss between the SSC DFB LD and the silica waveguide was about 3.78 dB. The light-current curve of the LD flip-chip bonded on the platform showed the almost linear increase of the output power without any saturation.     

System design and long-span transmission experiments on an optical FSK heterodyne single filter detection system

The influence of LD phase noise on a heterodyne noncoherent detection system was evaluated. Based on the evaluation, an optical FSK heterodyne single filter detection system with large frequency deviation and wide-band IF filter has been developed to allow use of stand-alone DFB LD's. In the system, a phase tunable DFB LD was used as an FSK transmitter light source to improve the FSK modulation characteristics. An IF filter with appropriate bandwidth evaded the influence of LD phase noise. With these configurations, long-span (243 km at 140 Mbit/s and 204 km at 280 Mhit/s) transmission experiments have been successfully carried out on this single filter detection system. To the contrary, influence of LD phase noise appeared in a limited IF bandwidth case, which agrees well with the theoretical evaluation.     

High-power SLM operation of 1.3 ?m InP/InGaAsP DFB LD with doubly buried heterostructure on p-type InP substrate

A newly developed buried heterostructure on p-type InP substrate was successfully applied to the fabrication of a 1.3 ?m DFB laser diode (LD). Stable CW SLM operation up to 31 mW at 30°C for an LD structure with two as-cleaved facets, and 53 mW at 25°C utilising AR coating, have been achieved.     

基于光纤CATV直接调制的若干问题分析

建立了ＤＦＢ－ＬＤ的宏观电路模型，并对ＤＦＢ－ＬＤ在直接调制下的光输出，进行了频谱分析。