This paper reviews the recent progress of quantum-dot semiconductor optical amplifiers developed as ultrawideband polarization-insensitive high-power amplifiers, high-speed signal regenerators, and wideband wavelength converters. A amplifier having a gain > 25 dB, noise figure < 5 3-dB saturation output power 20 dBm, over record widest bandwidth 90 nm among all kinds also penalty-free 23 highest was realized by using quantum dots. By utilizing isotropically shaped dots, TM gain, which is...

This work presents a theory of optical signal amplification and processing by quantum-dot semiconductor amplifiers (SOA's) based on the density matrix equations to treat electron-light interaction pulse propagation equations. The includes linear response as well incoherent coherent nonlinear new devices with arbitrary spectral spatial distribution quantum dots in active region under multimode light. was due hole burning reduction carrier stimulated emission. nonlinearity dynamic caused...

This paper presents recent progress in the field of semiconductor lasers and optical amplifiers with InAs-based self-assembled quantum dots active region for telecommunication. Based on our design terms maximum bandwidth high-speed modulation p-type doping high temperature stability, we realized temperature-insensitive 10 Gb s−1 laser diodes a GaAs substrate at 1.3 µm. The output waveform maintained clear eye opening, average power extinction ratio without current adjustments from 20°C to...

A semiconductor optical amplifier (SOA) having a gain of >25 dB, noise figure <5 and 3-dB saturation output power >19 dBm, over the record widest bandwidth 90 nm among all kinds amplifiers, also penalty-free 23 highest SOAs, was realized by using quantum dots.

This paper presents a theory and simulation of quantum-dot semiconductor optical amplifiers (SOAs) for high-bit-rate signal processing. The includes spatial isolation quantum dots, carrier relaxation excitation among the discrete energy states wetting layer, grouping dots by their resonant frequency under inhomogeneous broadening, homogeneous broadening single-dot gain, which are all essential to amplifier performance. We show that high-speed gain saturation occurs due spectral hole burning...

We demonstrate temperature-insensitive eye-opening under 10-Gb/s direct modulation of 1.3-µm p-doped quantum-dot lasers without using any current adjustments. The show a 6.5-dB extinction ratio between 20°C and 70°C. An active region consisting ten layers with p-type doping enabled this highly temperature-stable dynamic performance, which was much superior to conventional quantum-well lasers. These results make it possible use uncooled

We studied the injection current dependence of room-temperature lasing spectra a 1.3-μm self-assembled InAs∕GaAs quantum-dot laser both experimentally and theoretically. Starting from ground-state with few longitudinal modes, showed splitting, broadening, excited-state lasing, quenching as increased. could explain this unique by numerical simulation based on our theory, taking into account inhomogeneous homogeneous broadening optical gain well carrier relaxation processes in spatially...

Integrated photonic interconnect technology is free from the bandwidth-distance limitation that intrinsically exists in electrical interconnects, promising a disruptive alternative for next-generation scalable data centers. Silicon platforms have been reported based on monolithic and hybrid integration. Monolithic systems mitigate integration overhead but require compromise either electronic or device performance [1,2]. Hybrid allows independent process selection each so overall system can...

Ultrafast gain dynamics in quantum-dot (QD) optical amplifiers has been studied. It was found that there are at least three nonlinear processes, which attributed to carrier relaxation the ground states, phonon scattering, and capture from wetting layers into QDs. The relevant time constants were evaluated be /spl sim/90 fs, sim/260 sim/3 ps, respectively, under a 50-mA bias condition. dephasing sim/85 fs. third-order susceptibility (/spl chi//sup (3)/) by means of both transmission four-wave...

This paper provides a theory and simulation of traveling-type semiconductor optical amplifiers (SOAs) with self-assembled quantum dots in their active region. We calculated continuous-wave 40-Gbit/s dynamic performance, compared them 1.55-µm SOAs bulk InGaAsP layers. The results demonstrate that quantum-dot can process multiple-wavelength high bit-rate pulse trains over 40 Gbit/s under gain saturation. promises diverse functions like regeneration, reshaping, processing, wavelength...

Conversion efficiency to longer wavelengths in four-wave-mixing-based wavelength conversion optical semiconductor amplifiers is generally much lower than that the opposite direction. This study demonstrates experimentally this feature drastically improved, and asymmetry between directions eliminated by using quantum dots active layer. We attribute a reduction linewidth enhancement factor due discreteness of electron states dots.

Wavelength conversion using nondegenerate four-wave mixing in quantum-dot optical amplifiers is investigated. From the detuning frequency dependence of χ(3), derived from efficiency, we consider that, within range experiment, spectral-hole burning and carrier heating are responsible, that their time constants, i.e., relaxation to ground state phonon scattering time, 60–140 200–400 fs, respectively. This indicates supply level via higher levels very fast a broad bandwidth comparable...

We studied small-signal modulation characteristics of 1.3μm InAs∕GaAs self-assembled quantum-dot lasers in terms the efficiency and K factor as a function photon lifetime. could explain measured photon-lifetime dependence based on rate equation model considering explicitly carrier-capture process Pauli blocking quantum dots. Our shows how bandwidth is limited by time maximum modal gain via factor. present prerequisite designs active regions for over 10GHz modulation.

It is experimentally shown that the pattern effect inherent in semiconductor optical amplifiers can be eliminated by using self-assembled quantum dots active region. This property comes from ultrafast response of dominant gain nonlinearity, or spectral-hole burning, which respond as fast <3 ps due to intra-dot carrier relaxation, thereby enabling operation up 160 Gbit/s.

We report on the first all-optical switching operation of intersubband absorption at an optical communication wavelength (/spl sim/1.55 μm). The 1.55-μm was achieved by InGaAs-AlAs-AlAsSb coupled quantum wells. A ultrafast signal (equivalent to 1 THz) successfully demonstrated with a control pulse energy as low 27 pJ.

A nonlinear device capable of handling multiple wavelength channels simultaneously by using spectral-hole burning in the inhomogeneous broadening gain self-assembled quantum dots is proposed. The multichannel property this stems from localized absorption or change at pump within inhomogeneously broadened spectrum. spectral width modulation and its time evolution was also evaluated. result indicates applicability to operation.

Values for the nonlinearity and recovery time of 1.55 µm intersubband absorption have been experimentally obtained first by using InGaAs/AlAs/AlAsSb coupled quantum wells. The third-order susceptibility (χ(3)) has evaluated to be 5.8×10-17 m2/V2. An ultrafast (τ) ~685 fs while keeping figure merit (χ(3)/ατ) as large those interband transitions.

We have studied the polarization properties of cleaved-edge photoluminescence (PL) from InAs/GaAs self-assembled quantum dots. Transverse-electric (TE) and transverse-magnetic (TM) mode PL intensities been analyzed for dots having 8 nm InxGa1−xAs capping layer with indium (In) composition x=0 0.13. Polarization results show a dramatic change In compositions; TE-mode dominant is observed x=0, on other hand, TM-mode x=0.13. This has attributed to dot shape using transmission electron...

We successfully developed a high-density broadband 16-channel × 25 Gb/s on-package silicon photonics optical transceiver. The flip chip bonded bridge structure realized high density of about 363 Gb/s/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . demonstrated simultaneously on all 16 channels error-free operations with low crosstalk penalties Tx-to-Tx 1.4 dB, Rx-to-Rx and Tx-to-Rx <;0.1 dB.

Abstract We demonstrate that the pattern effect of semiconductor optical amplifiers appearing in amplified signals and cross‐gain modulated can be suppressed by using quantum dots as active media. This property, which originates from ultrafast (less than 3 ps) gain nonlinearity dominated spectral‐hole burning, principle enables pattern‐effect‐free operations at up to 160 Gb/s. Experimental confirmation this property was conducted 40

A change in the density and wavelength of InAs quantum dots (QDs) on InGaAsP/InP(100) substrate grown by metalorganic vapor-phase epitaxy (MOVPE) accordance with variation growth conditions was studied, aiming at optical device applications 1.55 μm region. In moderate V/III ratio region, size QDs found to decrease while increased as group-V source reduced, but other hand, both them monotonously increasing supply. The combination changing supply allowed us control independently so that a high...

We demonstrated transverse-magnetic (TM)-mode dominated gain at the 1.5μm wavelength in semiconductor optical amplifiers (SOAs) with columnar quantum dots (QDs). show that we can control polarization dependence of QD-SOAs by changing height and tensile-strained barrier QDs. The TM mode is 17.3dB a over 10dB was attained wide range 200nm. saturation output power 19.5dBm 1.55μm.

We have demonstrated a polarization-independent gain in semiconductor optical amplifiers that columnar quantum dots surrounded by strained side barriers 1.5-mum wavelength bands. obtained polarization-dependent of 0.5 dB with 10 and saturation output power 18 dBm at 1.55 mum.

We propose a class of wavelength-division multiplexing (WDM) demultiplexers having novel monitor and control scheme enabling dense WDM on Si nano-waveguide (NW) photonic integrated circuits (PICs), which had been impossible due to the critically small fabrication tolerance extremely miniaturized waveguide structure. With computer simulation, we show our proposed enable crosstalk in range -50 -40 dB, flat-topped spectrum for high spectral efficiency, channel counts as large 64. have...