High-gain mode-adapted semiconductor optical amplifier with12.4-dBm saturation output power at 1550 nm

A mode-adapted semiconductor optical amplifier (SOA) has been fabricated and packaged. At the gain peak, 1500 nm, the fiber to fiber gain was measured to be 32.5 dB. Statistics for eight packaged devices indicate that a fiber-to-fiber gain of 26.3 dB ± 1.3 dB and a saturation output power of 12.4 dBm ± 0.4 dBm are typical at a bias of 500 mA for λ = 1550 nm. Polarization sensitivity at 1550 nm was measured to be 1.1 dB ± 0.4 dB and the transverse electric (TE) polarization state noise figure (NF) was determined to be 7.0 dB ± 0.5 dB. The coupling loss was 1.3 dB ± 0.1 dB per facet. This SOA, with a 1.3-nm filter, was used as an optical preamplifier in a 10-Gb/s return-to-zero (RZ) system testbed with a pseudorandom binary sequence (PRBS) of 2³¹ -1. A 14.5-dB improvement in receiver sensitivity was observed at a bit error rate (BER) of 10^-11     

High-output-power polarization-insensitive semiconductor optical amplifier

A high-output-power 1550 nm polarization-insensitive semiconductor optical amplifier (SOA) was developed for use as a compact in-line optical amplifier. A very thin tensile-strained bulk structure was used for the active layer and active width-tapered spot-size converters (SSCs) were integrated on both input and output sides. The SOA module exhibited a high saturation output power of +17 dBm together with a low noise figure of 7 dB, large gain of 19 dB, and low polarization sensitivity of 0.2 dB for optical signals of 1550 nm wavelength. For the amplification of optical signals modulated at 10 Gb/s in the nonreturn-to-zero (NRZ) format, a good eye pattern without waveform distortion due to the pattern effect was obtained at an average output power of up to +12 dBm. Additionally, good amplification characteristics were demonstrated for the signal wavelength range corresponding to the C-band.     

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     

High-gain 1310-nm reflective semiconductor optical amplifiers with low-gain uncertainty

A 1310-nm reflective semiconductor optical amplifier with a gain uncertainty of only 0.8 dB at an average gain level of over 30 dB has been demonstrated using a microoptic polarization reversing retroreflector. For this amplifier 3-dB saturation output powers of up to 10 dBm and a noise figure of 7.5 dB have been obtained. A low gain uncertainty for undefined input signal polarization states and input signal wavelengths (which may vary over several nanometers) is of primary importance in switching applications.     

All-optical 1300-nm to 1550-nm wavelength conversion using cross-phase modulation in a semiconductor optical amplifier

All-optical 1300-nm to 1550-nm wavelength converters may be important components in lightwave networks which use both the 1300-nm and the 1550-nm low-loss transmission windows of silica optical fiber. We describe a new all-optical 1300-nm to 1550-nm wavelength converter, based on cross-phase modulation in a 1300-nm semiconductor optical amplifier. We demonstrate operation of the wavelength converter at 1.25 Gb/s, and present bit-error rate measurements. The wavelength converter demonstrated here potentially operates at high speed, with low input power and low polarization-sensitivity.     

Gain characteristics of quantum dot fiber amplifier based on asymmetric tapered fiber coupler

We theoretically analyzed the gain characteristics of an integrated semiconductor quantum dot (QD) fiber amplifier (SQDFA) by using a 2 × 2 tapered fiber coupler with a PbS QD-coated layer. The asymmetric structure of the fiber coupler is designed to have a maximum working bandwidth around 1550-nm band and provide a desired optical power ratio of the output signals. By using 600 mW of 980-nm pump, 10 dB gain of a 1550-nm signal is estimated with the gain efficiency of 4.5 dB/cm.     

AlGaInAs-InP材料系1550nm偏振无关半导体光放大器

采用低压金属有机气相外延设备生长并制作了1550nm AlGaInAs-InP偏振无关半导体光放大器,有源区为3周期的张应变量子阱结构,应变量为-0.40%.器件制作成脊型波导结构,并采用7°斜腔结构以有效抑制腔面反射.经蒸镀减反膜后,半导体光放大器的自发辐射功率的波动小于0.3dB,3dB带宽为56nm.半导体光放大器小信号增益近20dB,带宽大于55nm.在1500～1590nm波长范围内偏振灵敏度小于0.8dB,峰值增益波长的饱和输出功率达7.2dBm.     

Polarization independent optical phase conjugation with pump-signalfiltering in a monolithically integrated Mach-Zehnder interferometersemiconductor optical amplifier configuration

Demonstration of polarization independent optical phase conjugation by four-wave mixing in a monolithic Mach-Zehnder interferometric semiconductor optical amplifier (SOA) configuration. An integrated filtering mechanism for the pump-signal enhances the conjugate-to-pump ratio by 15 dB compared to the single SOA case     

27-dB gain unidirectional 1300-nm polarization-insensitive multiplequantum well laser amplifier module

An unidirectional polarization-insensitive multiple quantum well laser amplifier module for the 1300-nm window with a record high gain of 27 dB and a 3-dB saturation output power of 13 dBm is demonstrated. The module gain has a 3-dB width exceeding 60 nm and shows a typical polarization sensitivity and gain ripple as low as 0.3 dB. To provide immunity for backscattered or reflected light, polarization independent optical isolators were inserted in the input and output coupling optics of the package. A practical optical amplifier module for the 1300-nm window is very desirable, because most of the presently installed fiber has its zero dispersion wavelength around 1310 mm, while much of the older fiber often only can be operated around this wavelength     

1310-nm DBR-type MQW gain-clamped semiconductor optical amplifiers with AM-CATV-grade linearity

A 1310-nm gain clamped semiconductor optical amplifier with amplitude modulation CATV-grade linearity at an output power of 8 mW is demonstrated for the first time. The InGaAsP multiquantum-well laser amplifier is equipped with distributed Bragg reflectors at each end to supply the feedback necessary for gain clamping. The TE optical gain of 21.3 dB is measured to be constant within 0.1 dB up to 25-mW signal output power. Electrical signal distortion experiments are presented to demonstrate the linearity of the device.     

Monolithic Semiconductor Waveguide Device Concept for Picosecond Pulse Amplification, Isolation, and Spectral Shaping

In this paper, a waveguide device concept, named IRIS, is presented. The device consists of a monolithic array of concatenated semiconductor optical amplifiers and saturable absorbers. We have theoretically investigated picosecond pulse transmission through these devices. The parameters used in the simulation are representative for InP-InGaAsP bulk gain material, operating in the 1550-nm region. Operated as an optical amplifier for picosecond pulses, the simulation results show increased pulse peak amplification and decreased temporal broadening of the pulses for the IRIS devices as compared to a semiconductor optical amplifier of equivalent length. Used as a nonlinear element to increase the optical bandwidth of a picosecond pulse, the spectra obtained with IRIS devices show an increased broadening and smoothness as compared to a semiconductor optical amplifier. Finally the feasibility for using the IRIS device as an optical isolator is shown. It is operated in a regime where the device is transparent for a picosecond pulse train, while it is absorbent for lower power reflections.     

A compact external cavity wavelength tunable laser without an intracavity etalon

We propose a novel external cavity wavelength tunable laser (ECTL) configuration without an etalon inside the cavity. ECTL consists only of a semiconductor optical amplifier with an integrated phase section, and a liquid crystal tunable mirror. We successfully demonstrated excellent performances of the ECTL with fiber coupled output power of more than 50 mW over a 40-nm tuning range, sidemode suppression ratio of better than 45 dB, relative intensity noise of better than -148 dB/Hz, and linewidth of narrower than 2.3 MHz.     

Long-wavelength monolithic GaInNAs vertical-cavity optical amplifiers

We report on the continuous-wave amplification characteristics of an optically pumped 1.3-/spl mu/m multiple-quantum-well GaInNAs-GaAs vertical-cavity semiconductor optical amplifier (VCSOA). The VCSOA structure was monolithically grown by molecular beam epitaxy and operated in reflection mode in a fiber-coupled system. The maximum on-chip gain attained, limited by the onset of laser action, was 15.6 dB at 196 mW of 980-nm pump power. For a chip gain of 10.4 dB, the optical bandwidth was 10.8 GHz and the saturation output power was -9 dBm. By varying the pump laser power, a maximum extinction ratio of 22.3 dB was obtained. Temperature-controlled tuneable operation of the device is also presented and demonstration of 9 dB of chip gain obtained over 9.5 nm with an optical bandwidth of 12 GHz is reported.     

High-gain 1310 nm semiconductor optical amplifier modules with a built-in amplified signal monitor for optical gain control

A compact high-gain 1310-nm semiconductor optical amplifier (SOA) module incorporating two photodiodes to detect radiation emitted from the two opposite facets of the amplifier chip is reported. By subtracting their signals, a measure of the amplified signal is obtained without the need for optical filtering, Using this, amplified signals can be stabilized within 0.5 dB over a 25-dB range of input signals.     

Fabrication and characterization of 1 550 nm polarization-insensitive semiconductor optical amplifiers

Semiconductor Optical Amplifiers (SOAs) can beused asin-line amplifier ,preamplifier ,optical switch,andwavelength converter in future optical systems[1-3].Po-larization-independent gain,high output power and lowgain ripple are desirable features for most…     

Performance of a reconfigurable wavelength converter based ondual-pump-wave mixing in a semiconductor optical amplifier

We report on a wavelength converter based on dual pump wave mixing in an 1-mm-long bulk semiconductor optical amplifier. Very high conversion efficiency (more than 0 dB) and signal-to-background-noise ratio (SBR) (16 dB), for large down- or up-wavelength shifts (30 mn) has been achieved using parallel polarized pumps with low optical power (-13 dBm). Orthogonal polarized pumps result in worse performance, having the advantage of polarization insensitivity for small wavelength spacing between them. The converter operates in a fixed input-tunable output or a tunable input-fixed output mode of operation. In each mode, the measured SBR is almost independent of the wavelength shift for either up- or down-conversion     

Noise and gain band management of thulium-doped fiber amplifierwith dual-wavelength pumping schemes

Three dual-wavelength pumping schemes (1550 nm + 1064, 1047, or 1400 nm) have been experimentally assessed for the thulium-doped fiber amplifier in terms of power and noise performance. It is shown that 1047- and 1550-nm pumping gives a better power performance than 1064- and 1550-nm pumping at fixed gain peak wavelength (GPW). In addition, the most efficient pumping scheme appears to be 1400- and 1550-nm pumping for GPW higher than 1475 nm, and 1047 and 1550 nm for lower GPW. Noise figures lower than 6 db (with -5-dBm signal input power) are exhibited regardless the pumping schemes (although a 0.8-dB increase is reported for the 1400- and 1550-nm pumping)     

Active integrated photonic true time delay device

A photonic true time delay cell with two waveguide couplers and five semiconductor optical amplifiers is demonstrated. The five semiconductor optical amplifiers provide gain in the 1550-nm region and port selection to determine the time delay. With the amplifiers off the signal are blocked with extinction ratios of more than 10 dB. In the experiments reported here, the delay of 20 ns was provided by an optical fiber. Because of the potential for nanosecond switching times, the device has application in very agile phased array antenna applications, in optical switching and routing, and in optical filtering.     

Single-Polarization Cladding-Pumped Optical Amplifier Without Polarization-Maintaining Gain Fiber

We demonstrate a single-polarization cladding-pumped Er : Yb optical amplifier using a dual-pass design with a Faraday rotator mirror and nonpolarization-maintaining gain fiber. Over a 25-nm range centered at 1562 nm, the amplifier output exceeds 1 W and maintains a polarization extinction ratio greater than 22 dB. We investigate enhanced relative intensity noise inherent in the dual-pass configuration and discuss scaling to higher powers.     

High-performance semiconductor optical amplifier array forself-aligned packaging using Si V-groove flip-chip technique

A high performance four-tilted stripe InGaAsP semiconductor optical amplifier array, with low polarization sensitivity and very low-gain ripple, compatible with self-aligned flip-chip mounting on a Si motherboard is reported. Up to 32 dB of internal gain with 2-dB polarization sensitivity is obtained. A multifiber module has been realized, following an almost static optical alignment procedure, showing no degradation of the SOA array performances. Fiber-to-fiber gain, measured on the four stripes, is 14.4±1.3 dB with a gain ripple below ±0.1 dB