Digitally tunable channel dropping filter/equalizer based onwaveguide grating router and optical amplifier integration

We demonstrate a novel and powerful device that permits individual and simultaneous control of all the wavelength channels in a WDM system. The device is based on the monolithic integration of two identical waveguide grating routers with semiconductor optical amplifiers. By biasing appropriately the individual amplifier, each WDM channel can be amplified, detected or modulated. The device exhibits a channel bandwidth of 60 GHz, a channel spacing of 195 GHz and a crosstalk of -19 dB     

Monolithic integration of widely tunable sampled grating DBR laser with tilted semiconductor optical amplifier

High output powers and wide range tuning have been achieved in a sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier. Tilted amplifier and anti-reflection facet coating are used to suppress reflection. We have demonstrated sampled grating DBR laser with a tuning range over 38 nm, good wavelength coverage and peak output powers of more than 9 mW for all wavelengths.     

单片集成倾斜SOA的宽可调谐取样光栅分布布拉格反射激光器

高功率和宽调谐范围的单片集成倾斜SOA的宽可调谐取样光栅分布布拉格反射激光器被成功制备。倾斜的SOA结构和端面增透膜有效的降低了端面的反射率。器件调谐范围大于38nm,波长覆盖较好,调谐范围内波长输出功率均大于9mW。     

Digitally tunable wavelength filter and laser

A novel nonmechanical, digitally tunable, polarization insensitive and optically transparent wavelength filter using holograms electro-optically written on a ferroelectric liquid crystal (FLC) spatial light modulator (SLM) has been constructed and operated to tune to discrete wavelengths spaced by 1.3 nm. The filter has been incorporated in a ring laser which is tunable over a range of 38.5 nm across the erbium window, giving output powers of 10 mW. Both wavelength filter and tunable laser are suitable for wavelength division multiplexing (WDM) applications.     

Widely (132 nm) wavelength tunable laser using a semiconductor optical amplifier and an acousto-optic tunable filter

A widely wavelength tunable laser combining a semiconductor optical amplifier, an acousto-optic tunable filter and a Fabry-Perot etalon has been developed. It exhibited good characteristics over a 132 nm (1480-1612 nm) tuning range.     

Widely tunable wavelength converter using a double-ring fiber laser with a semiconductor optical amplifier

Widely tunable wavelength conversion has been demonstrated using broad-band orthogonal-pump four-wave mixing in a semiconductor optical amplifier placed at the intersection of two fiber ring lasers. The all-optical wavelength converter operates without using any external pump source. A 3-dB conversion-range over 40 nm is obtained. The measured power penalty is 1.5 dB for a 2.5-Gb/s converted signal at 10/sup -9/ bit error rate.     

Optical signal processing based on semiconductor optical amplifier and tunable delay interferometer

In this paper,several applications in all-optical signal processing based on a semiconductor optical amplifier (SOA) and variable delayed interferometers (DIs) have been experimentally demonstrated.Wavelength converter based on a nonlinear polarization switch (NPS) and a DI is proposed and presented for the wavelength conversion of nonretum-to-zero (NRZ) signals.An alloptical nonretum-to-zero to return-to-zero (NRZ-to-RZ)format converter with tunable duty cycles is achieved by the DI with variable delays.The 40 Gb/s reconfigurable optical OR/NOR gate in a single SOA,followed a tunable optical bandpass filter (OBF) and a DI,optical 2R regeneration using an SOA-DI are investigated.It is found that this combinative realization of filters has been endowed with great flexibility and quality for 40 Gb/s optical logic and 2R regeneration.     

空间级联可调谐光滤波器方式实现光分插复用器

提出一种采用空间级联可调谐光滤波器方式实现的OADM.该器件不但具有集成度高、体积小、插入损耗低、信道间插入损耗差异小的特点,而且能够在控制电路的作用下灵活选择上下路波长及其数量,为构建灵活、高性能的WDM网络提供了选择.     

Proposals and analyses on laser amplifier based integrated optical circuits

Simplified traveling wave laser (TWL) amplifier equations are given based on a lumped model. Pulse transfer characteristics for a TWL amplifier are examined theoretically. A new class of integrated optical amplifier with three terminals (OPATT) has been proposed as an optical analog of the electric transistor. Analytical formulas and dynamic properties of an OPATT have been considered. OPATT-based optical integrated circuits, including optical differential amplifiers, comparators, saturable oscillators, and optical logic gates, have been investigated theoretically.     

Automatic frequency control in a semiconductor laser and an optical amplifier

Automatic frequency control (AFC) in an injection locked or resonant type amplifier in an AlGaAs semiconductor laser was achieved through using the terminal voltage change induced by light injection. Signal-to-noise ratio in the control signal of 10 dB was obtained when the input optical power was -47 dBm and the optical gain Was 51 dB. The AFC was maintained for 3 h with an 0.3-percent output power fluctuation for 2°C ambient temperature change and 65-MHz frequency stability. Step response showed that the system response time was 1.5 s. Sensitivity to input optical power deteriorates at -49 dBm, with a 53-dB locking gain, because of frequency deviation caused by temperature modulation. The second derivative of the induced voltage and it's relation to the optical frequency is constant at5 times 10^{-10}[V/(MHz)²] for all input power levels in a buried-heterostructure (BH)-AlGaAs laser. Terminal voltage change induced by light injection is calculated by simple rate equations with a Gaussian-Halperin-Lax (GHL) bandtail model. Good agreement with experimental results was seen.     

Widely tunable complex-coupled distributed feedback laser with photonic Crystal mirrors and integrated optical amplifier

We report the development of a current-controlled widely tunable laser diode based on InP with photonic crystal mirrors and an integrated amplifier section for stabilized power output. The laser consists of three longitudinally coupled ridge waveguide cavities that are coupled through photonic crystal mirror segments. A laterally defined binary superimposed grating provides complex-coupled distributed feedback into two of the laser cavities. The wavelength can be switched over a range of 26 nm. Through adjustment of the current into a third amplifier section, the output power can be stabilized over the tuning range of the laser.     

Digitally tunable optical filters using arrayed-waveguide grating(AWG) multiplexers and optical switches

Two novel configurations for digitally tunable optical filters based on arrayed-waveguide grating (AWG) multiplexers are described in detail with emphasis on the connection of the AWG multiplexer and optical switches. Performance comparisons show that conventional configurations are disadvantaged by the switch size required and loss imbalance among the optical frequency-division-multiplexed (FDM) channels; the proposed configurations require only O(√(N)) switch elements to select one of N FDM channels, and the loss imbalance is lower by up to 75% in decibel     

采用可调谐激光器提高光纤延迟线精度的研究

为了提高一种3bit可变光纤延迟线的延时精度,提出一种采用可调谐激光器作为系统光源的技术,利用光纤的材料色散特性即光纤的折射率随传输波长变化而改变的特点,来改变延时光纤中信号存储的时间,从而达到提高光纤延迟线延时精度的目的。仿真结果表明,采用该种技术的光纤延迟线系统,平均延时误差从4.1ps下降到了1.3ps,延时精度得到了显著提高。     

Widely tunable polarization-independent all-optical wavelengthconverter using a semiconductor optical amplifier

We report a polarization-independent widely tunable four-wave mixing wavelength converter using polarization diversity and broad-band orthogonal pumps in a single semiconductor optical amplifier. The conversion efficiency is nearly constant (less than 3-dB variation) over a 36-nm range with less than 0.34 dB polarization sensitivity. The power penalty at 10^-9 bit error rate for a 10-Gb/s signal is less than 0.9 dB     

WDM-PON system based on the laser light injected reflective semiconductor optical amplifier

This paper proposes a WDM-PON system which uses the laser light injected reflective semiconductor optical amplifier (R-SOA) as the optical transmitter. In the system, optical carrier of laser lights is supplied from the central office (CO) to the R-SOA both in CO and in the subscriber's side. The optical carrier consists of a pair of the perpendicularly polarized laser lights to avoid the polarization dependence of R-SOA. The optical carrier can be shared by several WDM-PON systems to save the cost. We measured the transmission performance of R-SOA which modulates the polarization mixed injection laser at 1.25 Gbps. It is shown that the combined effect of Rayleigh backscattering and the intensity noise induced by the feedback of optical signals into the R-SOA increases the required level of optical injection power into the R-SOA.     

Frequency and wavelength tunable optical microwave source based on a distributed Bragg reflector self-pulsation laser

A frequency and wavelength tunable self-pulsation laser based on DBR laser devices is reported for the first time.This laser generates continuous tunable optical microwave in the range of 1.87-21.81 GHz with 3-dB linewidth about 10 MHz by tuning the injection currents on the front and back gain sections,and exhibits wavelength tuning range from 1536.28 to 1538.73 nm by tuning the injection currents on the grating section.     

基于DBR结构自脉动激光器的波长及频率可变光微波源

首次报道了基于DBR结构自脉动激光器的波长及频率可变光微波源。该微波源可以或得1.87GHz至21.81GHz的微波信号同时可以获得1536.28nm至1538.73nm的波长调谐。     

Multichannel FSK experiment using an optical amplifier repeater and wavelength tunable direct detection receiver

A four channel direct detection FDM operating at 565 Mbit/s with a channel spacing of 12 GHz which achieves a receiver sensitivity of -40 dBm is reported. A laser preamplifier is used to overcome the optical processing loss of the channel selective filter.<>     

A combined tunable optical filter and tunable MQW ring laser

A dual-purpose, grating-based tunable optical filter/ring laser is described for accurate wavelength selection and generation at customer terminals. The device selects a single-wavelength channel from a HDWDM multiplex with 1 nm channel spacing, and simultaneously generates an identical wavelength as part of a tunable ring laser. The device is tunable over a 125 nm wavelength range, centered in the 1.5 μm low-loss fiber window     

Generation of an ultra-wideband triplet signal based on semiconductor optical amplifier

We propose a novel ultra-wideband (UWB) triplet signal source based on the cross-gain modulation (XGM) in semiconductor optical amplifier (SOA). In the proposed scheme, only an optical source and two SOAs are needed, so the all-optical structure is compact. A triplet optical pulse with center frequency of 6.25 GHz and fractional bandwidth of 83% is obtained by the scheme. The extinction ratio can be improved by the counter-propagating scheme. The triplet pulse signal with only one wavelength can be easily controlled, and can aviod the dispersion effect. The output triplet pulse signal is insensitive to the light wavelength shifts, its available wavelength range is wide, the dynamic range of the input power is more than 6 dBm, and the bias current of the SOAs is exhibited.