Showing papers on "Laser linewidth published in 2005"
TL;DR: In this paper, a high-speed, frequency swept, 1300 nm laser source for frequency domain reflectometry and OCT with Fourier domain/swept source detection is presented, which uses a fiber coupled, semiconductor amplifier and a tunable fiber Fabry-Perot filter.
Abstract: We demonstrate a high-speed, frequency swept, 1300 nm laser source for frequency domain reflectometry and OCT with Fourier domain/swept-source detection. The laser uses a fiber coupled, semiconductor amplifier and a tunable fiber Fabry-Perot filter. We present scaling principles which predict the maximum frequency sweep speed and trade offs in output power, noise and instantaneous linewidth performance. The use of an amplification stage for increasing output power and for spectral shaping is discussed in detail. The laser generates ~45 mW instantaneous peak power at 20 kHz sweep rates with a tuning range of ~120 nm full width. In frequency domain reflectometry and OCT applications the frequency swept laser achieves 108 dB sensitivity and ~10 mum axial resolution in tissue. We also present a fast algorithm for real time calibration of the fringe signal to equally spaced sampling in frequency for high speed OCT image preview.
634 citations
TL;DR: In this paper, the authors report the characterization results for a fully packaged widely tunable digital supermode (DS) distributed Bragg reflector (DBR) laser which has been monolithically integrated with a semiconductor optical amplifier.
Abstract: We report recent device characterization results for a fully packaged widely tunable digital supermode (DS) distributed Bragg reflector (DBR) laser which has been monolithically integrated with a semiconductor optical amplifier. This new device gives all of the wide tunability and high side-mode suppression ratio performance previously reported for the DS-DBR laser with the added feature of output powers in excess of 14 dBm in fiber. In addition to output power and basic tuning behavior, we report on linewidth and relative intensity noise measurements for this device in order to investigate the noise characteristics of this laser.
261 citations
TL;DR: In this article, a cavity enhanced absorption spectroscopy (OF-CEAS) was proposed to record the transmission maxima of the successive TEMoo resonances of a high-finesse optical cavity when a Distributed Feedback Diode Laser is tuned across them.
Abstract: A new technique of cavity enhanced absorption spectroscopy is described. Molecular absorption spectra are obtained by recording the transmission maxima of the successive TEMoo resonances of a high-finesse optical cavity when a Distributed Feedback Diode Laser is tuned across them. A noisy cavity output is usually observed in such a measurement since the resonances are spectrally narrower than the laser. We show that a folded (V-shaped) cavity can be used to obtain selective optical feedback from the intracavity field which builds up at resonance. This induces laser linewidth reduction and frequency locking. The linewidth narrowing eliminates the noisy cavity output, and allows measuring the maximum mode transmissions accurately. The frequency locking permits the laser to scan stepwise through the successive cavity modes. Frequency tuning is thus tightly optimized for cavity mode injection. Our setup for this technique of Optical-Feedback Cavity-Enhanced Absorption Spectroscopy (OF-CEAS) includes a 50 cm folded cavity with finesse ∼20 000 (ringdown time ∼20 μs) and allows recording spectra of up to 200 cavity modes (2 cm−1) using 100 ms laser scans. We obtain a noise equivalent absorption coefficient of ∼5×10−10 cm−1 for 1 s averaging over scans, with a dynamic range of four orders of magnitude.
235 citations
TL;DR: An improved mounting configuration for a passive optical cavity used for laser frequency stabilization with associated reduction of the vibration sensitivity of the effective cavity length has led to a simple and compact reference cavity system for laser stabilization at the level of 1 Hz linewidth.
Abstract: We report an improved mounting configuration for a passive optical cavity used for laser frequency stabilization. The associated reduction of the vibration sensitivity of the effective cavity length has led to a simple and compact reference cavity system for laser stabilization at the level of 1 Hz linewidth.
222 citations
TL;DR: In this article, surface plasmon (SP)-enhanced random laser emission from a suspension of silver nanoparticles in a laser dye operating at diffusive and sub-diffusive scattering strengths was reported.
Abstract: We report on surface plasmon (SP)-enhanced random laser emission from a suspension of silver nanoparticles in a laser dye operating at diffusive and subdiffusive scattering strengths. SP resonance enhances the scattering cross section, while the geometrical cross section remains small, thus providing a large gain volume. The localized electromagnetic field near the particle surface leads to enhanced absorption of excitation light and larger amplification of fluorescence. The metal-nanoparticle-based random laser yields larger linewidth narrowing at lower pump fluence threshold than a dielectric-scatterer-based random laser under equivalent conditions. These findings open the door to studies of applications related to light amplification assisted by SP in metallic nanoparticles.
185 citations
TL;DR: In this article, a coherent phase-locked laser array was demonstrated by combining the outputs of seven individual fiber lasers together in a self-Fourier cavity, and the total output power of this laser array when operated as a coherent ensemble was 0.4watts.
Abstract: A coherent phase-locked laser array has been experimentally demonstrated by combining the outputs of seven individual fiber lasers together in a self-Fourier cavity. By analyzing the interference fringes of the laser output in the far field of the array, a fringe visibility was measured of V=0.87, indicating a coherence of 0.73. The total output power of this laser array when operated as a coherent ensemble was 0.4watts.
171 citations
TL;DR: A Brillouin gain coefficient gB of 6.0 x 10(-9) m/W, about 134 times larger than that of fused silica fiber, is obtained for As2Se3 single mode fiber from measurements of BrillouIn threshold power and the gain linewidth.
Abstract: Strong stimulated Brillouin scattering in single-mode As2Se3 chalcogenide fiber is observed using a cw laser at 1.55 microm wavelength region. Brillouin threshold for a 5-m-long fiber is as small as 85 mW. The Brillouin frequency shift vB and the gain linewidth DeltavB are 7.95 GHz and 13.2 MHz, respectively, measured with heterodyne detection and an RF spectrum analyzer. A Brillouin gain coefficient gB of 6.0 x 10(-9) m/W, about 134 times larger than that of fused silica fiber, is obtained for As2Se3 single mode fiber from measurements of Brillouin threshold power and the gain linewidth.
160 citations
TL;DR: A single-mode, linearly polarized, 1118 nm ytterbium fiber laser was applied to pumping of a short fiber length, polarization-maintaining Raman cavity, resulting in a 0.4 nm linewidth, 23 W CW source at 1179 nm.
Abstract: A single-mode, linearly polarized, 1118 nm ytterbium fiber laser was applied to pumping of a short fiber length, polarization-maintaining Raman cavity, resulting in a 0.4 nm linewidth, 23 W CW source at 1179 nm. Efficient, single-pass frequency doubling of the Raman source in MgO doped PPLN to 589 nm was demonstrated with CW power levels in excess of 3 W. No beam quality degradation was observed due to photorefraction at pump power densities up to 2 MW/cm2. The proposed approach can be readily extended to Watt-level generation of any desired wavelength in the 560 to 770 nm range.
156 citations
TL;DR: Single-dot luminescence spectroscopy showed a continuous line narrowing towards lower temperatures with a linewidth as sharp as 2 meV at 35 K, proving the atomiclike emission from silicon quantum dots subject to quantum confinement.
Abstract: Single-dot luminescence spectroscopy was used to study the emission linewidth of individual silicon nanocrystals from low temperatures up to room temperature. The results show a continuous line nar ...
156 citations
TL;DR: In this article, a diode-pumped single-frequency piezoelectrically tuned fiber laser with narrow spectral linewidth has been used as a light source in applications for long-range coherent frequency-domain reflectometry.
Abstract: A diode-pumped single-frequency piezoelectrically tuned fiber laser with narrow spectral linewidth has been used as a light source in applications for long-range coherent frequency-domain reflectometry. Frequency-modulated continuous-wave (FMCW) measurements of Rayleigh back-scattering and Fresnel reflection from a 95-km-long fiber have been demonstrated without the use of an optical amplifier. This is, to our knowledge, the longest distance measurement with FMCW. The high sensitivity and dynamic range of the long-range backscattering measurements benefit from the extremely long coherence length of the narrow linewidth fiber laser, which has been estimated to be 210 km in air.
152 citations
TL;DR: In this paper, a new multifrequency quasi-optical electron paramagnetic resonance (EPR) spectrometer is described, which is suitable for transient EPR at 120 and 240 GHz.
Abstract: A new multifrequency quasioptical electron paramagnetic resonance (EPR) spectrometer is described. The superheterodyne design with Schottky diode mixer/detectors enables fast detection with subnanosecond time resolution. Optical access makes it suitable for transient EPR (TR-EPR) at 120 and 240 GHz. These high frequencies allow for an accurate determination of small g-tensor anisotropies as are encountered in excited triplet states of organic molecules like porphyrins and fullerenes. The measured concentration sensitivity for continuous-wave (cw) EPR at 240 GHz and at room temperature without cavity is 1013spins∕cm3 (15 nM) for a 1 mT linewidth and a 1 Hz bandwidth. With a Fabry-Perot cavity and a sample volume of 30 nl, the sensitivity at 240 GHz corresponds to ≈3×109 spins for a 1 mT linewidth. The spectrometer’s performance is illustrated with applications of transient EPR of excited triplet states of organic molecules, as well as cw EPR of nitroxide reference systems and a thin film of a colossal magn...
TL;DR: In this article, the authors describe 1.1 and 1.3 µm p-doped tunnel injection self-organized In(Ga)As quantum dot (QD) laser emitting at 1.2 × 10−16 cm3.
Abstract: The modulation bandwidth of conventional 1.0–1.3 µm self-organized In(Ga)As quantum dot (QD) lasers is limited to ~6–8 GHz due to hot carrier effects arising from the predominant occupation of wetting layer/barrier states by the electrons injected into the active region at room temperature. Thermal broadening of holes in the valence band of QDs also limits the performance of the lasers. Tunnel injection and p-doping have been proposed as solutions to these problems. In this paper, we describe high-performance In(Ga)As undoped and p-doped tunnel injection self-organized QD lasers emitting at 1.1 and 1.3 µm. Undoped 1.1 µm tunnel injection lasers have ~22 GHz small-signal modulation bandwidth and a gain compression factor of 8.2 × 10−16 cm3. Higher modulation bandwidth (~25 GHz) and differential gain (3 × 10−14 cm2) are measured in 1.1 µm p-doped tunnel injection lasers with a characteristic temperature, T0, of 205 K in the temperature range 5–95°C. Temperature invariant threshold current (infinite T0) in the temperature range 5–75°C and 11 GHz modulation bandwidth are observed in 1.3 µm p-doped tunnel injection QD lasers with a differential gain of 8 × 10−15 cm2. The linewidth enhancement factor of the undoped 1.1 µm tunnel injection laser is ~0.73 at lasing peak and its dynamic chirp is <0.6 A at various frequencies and ac biases. Both 1.1 and 1.3 µm p-doped tunnel injection QD lasers exhibit zero linewidth enhancement factor (α ~0) and negligible chirp (< 0.2 A). These dynamic characteristics of QD lasers surpass those of equivalent quantum well lasers.
Journal Article•
TL;DR: The first direct measurements of femtosecond electronic dephasing in CdSe nanocrystals are reported using three-pulse photon echoes and a novel mode-suppression technique to separate the dynamics of the coherently excited LO phonons from the underlying electron-hole dephase by suppressing the quantum beats.
Abstract: We report the first direct measurements of femtosecond electronic dephasing in CdSe nanocrystals using three-pulse photon echoes and a novel mode-suppression technique. We are able to separate the dynamics of the coherently excited LO phonons from the underlying electron-hole dephasing by suppressing the quantum beats. The homogeneous linewidth of these materials at 15 K results from electronic dephasing in -85 fs, approximately half of which is due to acoustic phonon modes. Contributions from acoustic phonons dominate the homogeneous linewidth at room temperature.
TL;DR: In this article, a single nickel-nitrogen (NE8) defect center in diamond by chemical vapor deposition is demonstrated. And the same authors used a Hanbury-Brown and Twiss interferometer to demonstrate the antibunching of single centers.
Abstract: Fabrication of single nickel-nitrogen (NE8) defect centers in diamond by chemical vapor deposition is demonstrated. Under continuous-wave 745nm laser excitation single defects were induced to emit single photon pulses at 797nm with a linewidth of 1.5nm at room temperature. Photon antibunching of single centers was demonstrated using a Hanbury–Brown and Twiss interferometer. Confocal images revealed approximately 106 optically active sites∕cm2 in the synthesized films. The controlled fabrication of an NE8 based single photon source in synthetic diamond is important for fiber based quantum cryptography, and potentially linear optics quantum computing.
TL;DR: In this article, the chirp characteristics of 40-Gb/s directly modulated 1.55-/spl mu/m distributed-feedback laser diodes (DFB-LDs) were investigated.
Abstract: For short-reach applications, 40-Gb/s directly modulated semiconductor lasers enable high-capacity transmission with a simple and low-cost configuration. We investigated the chirp characteristics of 40-Gb/s directly modulated 1.55-/spl mu/m distributed-feedback laser diodes (DFB-LDs) and measured the linewidth enhancement factor and dynamic chirp. We then evaluated the fiber-dispersion dependence of the bit error rates (BERs) and dispersion tolerance for 40-Gb/s transmissions.
TL;DR: An optical atomic clock scheme is proposed that utilizes two lasers to establish coherent coupling between the 5s2 1S0 ground state of 88Sr and the first excited state, 5s5p 3P0, exploiting the phenomenon of electromagnetically induced transparency.
Abstract: An optical atomic clock scheme is proposed that utilizes two lasers to establish coherent coupling between the 5s2 1S0 ground state of 88Sr and the first excited state, 5s5p 3P0. The coupling is mediated by the broad 5s5p 1P1 state, exploiting the phenomenon of electromagnetically induced transparency. The effective linewidth of the clock transition can be chosen at will by adjusting the laser intensity. By trapping the 88Sr atoms in an optical lattice, long interaction times with the two lasers are ensured; Doppler and recoil effects are eliminated. Based on a careful analysis of systematic errors, a clock accuracy of better than 2 x 10(-17) is expected.
TL;DR: In this article, a single particle level spectral analysis of spherical CdSe nanocrystals capped by a CdS rod-like shell was carried out and the results showed a high degree of correlation between the emission energy, spectral linewidth, phonon coupling strength, and emission intensity of the single nanocrystal.
Abstract: Spherical CdSe nanocrystals capped by a CdS rod-like shell exhibit interesting spectral dynamics on the single particle level. Spectral boxcar averaging reveals a high degree of correlation between the emission energy, spectral linewidth, phonon coupling strength, and emission intensity of the single nanocrystal. The results can be described in terms of a spatially varying surface charge density in the vicinity of the exciton localized in the CdSe core, leading to a quantum confined Stark effect which modifies the transition energy and the radiative rate. Whereas internal charging of the particle results in a change in the nonradiative rate, surface charges primarily influence the radiative rate. Additionally, we observe characteristic spectral dynamics in frequency space, the magnitude of which depends slightly on temperature and strongly on excitation density. By distinguishing between continuous spectral jitter and discrete spectral jumping associated with a reversible particle ionization event, we can attribute the spectral dynamics to either a slowly varying surface charge density or a rapidly occurring polarization change due to a reversible expulsion of a charge carrier from the semiconductor nanostructure. Whereas the former exhibits universal Gaussian statistics, the latter is best characterized by a Lorentzian noise spectrum. The Gaussian spectral noise increases with spectral redshift of the emission and with increasing proximity of the surface charge to the localized exciton. The observation of a high degree of correlation between peak position and linewidth right up to room temperature suggests applications of the nanocrystals as extremely sensitive single charge detectors in both solid state devices and in biomolecular labeling, where highly local measurements of the dielectric environment are required. Nanoscale control of the physical shape of nanocrystals provides a versatile test bed for studying electronic noise, making the approach relevant to a wide range of conducting and emissive solid state systems.
TL;DR: In this paper, the dynamics of the organic laser guest-host composite of tris-(8-hydroxy quinoline) aluminium and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran embedded in a high-Q (Q≈4500) double distributed Bragg reflector microcavity using subpicosecond up-conversion techniques were investigated.
Abstract: We investigate the dynamics of the organic laser guest-host composite of tris-(8-hydroxy quinoline) aluminium and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran embedded in a high-Q (Q≈4500) double distributed Bragg reflector microcavity using subpicosecond up-conversion techniques. Lasing is observed at a threshold of 0.4nJ∕20μJcm−2 with a linewidth of 0.05 nm (resolution limit). We observe a strongly nonlinear intensity-dependent delay of the emitted radiation burst. All experimental results are successfully modeled by a set of nonlinear rate equations, emphasizing the importance of a feedback mechanism for lasing.
TL;DR: The frequency doubling of a 110-W linearly polarized diffraction-limited Yb-doped fiber oscillator power amplifier (FOPA) has generated 60-W near-diffraction- limited (M2 < or = 1.33) linearly polarization green output.
Abstract: The frequency doubling of a 110-W linearly polarized diffraction-limited Yb-doped fiber oscillator power amplifier (FOPA) has generated 60-W near-diffraction-limited (M2 < or = 1.33) linearly polarized green output. The FOPA produces as much as 2.4 kW of peak power and less than 20-pm linewidth at a 10-MHz repetition rate and 5-ns pulse duration without the onset of nonlinear effects. With two lithium triborate crystals at noncritical phase matching, a maximum of 54.5% doubling efficiency has been demonstrated. The overall electrical efficiency to the green portion of the spectrum is 10%.
TL;DR: In this paper, the growth over 2 in. sapphire substrates of crack-free fully epitaxial nitride-based microcavities using two highly reflective lattice-matched AlInN∕GaN distributed Bragg reflectors (DBRs) was reported.
Abstract: We report the growth over 2 in. sapphire substrates of crack-free fully epitaxial nitride-based microcavities using two highly reflective lattice-matched AlInN∕GaN distributed Bragg reflectors (DBRs). The optical cavity is formed by an empty 3λ∕2 GaN cavity surrounded by AlInN∕GaN DBRs with reflectivities close to 99%. Reflectivity and transmission measurements were carried out on these structures, which exhibit a stopband of 28 nm. The cavity mode is clearly resolved with a linewidth of 2.3 nm. These results demonstrate that the AlInN∕GaN system is very promising for the achievement of strong light–matter interaction and the fabrication of nitride-based vertical cavity surface emitting lasers.
TL;DR: In this paper, the performance of distributed feedback lasers (DFBs) based on InAs/InGaAs quantum dots (QDs) is studied, and the effect of gain saturation with the carrier density on the linewidth of DFLs is analyzed.
Abstract: The dynamic properties of distributed feedback lasers (DFBs) based on InAs/InGaAs quantum dots (QDs) are studied. The response function of QD DFBs under external modulation is measured, and the gain compression with photon density is identified to be the limiting factor of the modulation bandwidth. The enhancement of the gain compression by the gain saturation with the carrier density in QDs is also analysed for the first time. The linewidth of the QD DFBs is found to be more than one order of magnitude narrower than that of conventional quantum well (QW) DFBs at comparable output powers. The figure of merit for the narrow linewidth is compared between different semiconductor materials, including bulk, QWs and QDs. Linewidth re-broadening and the effects of gain offset are also investigated. Finally, the chirp of QD DFBs is studied by time-resolved-chirp measurements. The wavelength chirping of the QD DFBs under 2.5 Gbps modulation is characterized. The strong dependence of the linewidth enhancement factor on the photon density is explained by the enhancement of gain compression by the gain saturation with the carrier density, which is related to the inhomogeneous broadening and spectral hole burning in QDs.
TL;DR: In this article, a broadband mm-wave transmission link for downstream transmission is investigated, where a dual-frequency optical source based on suppressed-carrier double-sideband modulation of a narrow linewidth laser is created.
Abstract: A broad-band millimeter-wave (mm-wave) transmission link for downstream transmission is investigated. The mm-wave carrier is created by a dual-frequency optical source based on suppressed-carrier double-sideband modulation of a narrow linewidth laser. The optical sidebands generated in the modulation are divided into two separate fibers by filtering with fiber Bragg gratings. One of the waves is modulated with baseband data up to 2.5 Gb/s. The fibers are combined and connected with the base station (BS) via a single-mode fiber. At the BS, the mm-wave modulated signal with data is created with a wide bandwidth photodetector through heterodyne mixing of the two optical waves. This mm-wave signal is amplified and transmitted to the mobile unit, where the reception is performed using self-homodyne mixing, in order to ensure carrier frequency independence. Error-free data transmission was demonstrated for the downlink after 44 km of single-mode optical fiber.
TL;DR: In this article, the performance of a photonic band-edge laser fabricated from a low molar mass dye-doped chiral nematic liquid crystal is found to have a strong thermal dependence.
Abstract: The performance of a photonic band-edge laser fabricated from a low molar mass dye-doped chiral nematic liquid crystal is found to have a strong thermal dependence. At each temperature the performance of the laser has been characterized by the slope efficiency which was calculated from a plot of the emission energy as a function of excitation energy. This slope efficiency was found to increase by 36% when the dye-doped chiral nematic liquid crystal was cooled from 53to43°C. The increase in slope efficiency is considered to be due to a change in the lasing conditions, in particular, changes in the emission efficiency of the dye and possibly the quality factor of the liquid-crystal resonator, which is dependent upon the linewidth of the resonant mode. The wavelength dependency of the spontaneous emission intensity and the quantum efficiency of the dye were not found to influence the lasing conditions in this case. The order parameters relating to the dye-doped chiral nematic liquid crystal were considered t...
TL;DR: In this paper, a femtosecond broad-band multiplex spectroscopy setup with a polycrystalline Pt electrode with both CO-free and CO-saturated electrolytes was used for simultaneous electrochemical and vibrational sum-frequency generation.
TL;DR: Giant effective linewidth enhancement factors, close to 60, are measured on a quantum dot laser under specific biasing conditions in this paper, where 2.5 Gbit/s purely frequency modulated signal is obtained by direct current modulation at this operation point.
Abstract: Giant effective linewidth enhancement factors, close to 60, are measured on a quantum dot laser under specific biasing conditions. Consequently, 2.5 Gbit/s purely frequency modulated signal is obtained by direct current modulation at this operation point.
10 May 2005
TL;DR: In this article, the authors proposed simple changes to the measurement algorithm that, if adopted by metrology instrument suppliers, would permit estimation of linewidth roughness without bias caused by image noise.
Abstract: Linewidth roughness (LWR) is usually estimated simply as three standard deviations of the linewidth. The effect of image noise upon this metric includes a positive nonrandom component. The metric is therefore subject to a bias or "systematic error" that we have estimated can be comparable in size to the roughness itself for samples as smooth as required by the industry roadmap. We illustrate the problem using scanning electron microscope images of rough lines. We propose simple changes to the measurement algorithm that, if adopted by metrology instrument suppliers, would permit estimation of LWR without bias caused by image noise.
TL;DR: The results indicate that the much debated steep rise of the fluorescence lifetime of pseudoisocyanine aggregates above 40 K results from the fact that this coherence length drops below the localization length imposed by static disorder.
Abstract: We study the temperature-dependent dephasing rate of excitons in chains of chromophores, accounting for scattering on static disorder as well as acoustic phonons in the host matrix From this we find a power-law temperature dependence of the absorption linewidth, in excellent quantitative agreement with experiments on dye aggregates We also propose a relation between the linewidth and the exciton coherence length imposed by the phonons The results indicate that the much debated steep rise of the fluorescence lifetime of pseudoisocyanine aggregates above 40 K results from the fact that this coherence length drops below the localization length imposed by static disorder
TL;DR: In this article, a comparison between two kinds of single-frequency Sb-based semiconductor VCSELs operating at 2.3 /spl mu/m in continuous-wave regime at room temperature is presented.
Abstract: We present a comparison between two kinds of single-frequency Sb-based semiconductor VCSELs operating at 2.3 /spl mu/m in continuous-wave regime at room temperature. These lasers are studied in view of application to spectroscopy or trace gas detection. Both are based on a molecular beam epitaxy grown half-VCSEL. In the first configuration, a dielectric mirror is deposited on top to form a microcavity, while in the second a concave mirror is used to form an external cavity. The external cavity VCSEL exhibits 5-mW output power, a narrow linewidth (<<20 kHz), and 50-GHz continuous frequency tunability.
TL;DR: In this paper, the effect of annealing on the concentration of localized states and/or the localization length of excitons in (GaIn)(NAs) quantum wells is investigated.
Abstract: Photoluminescence in (GaIn)(NAs) quantum wells designed for laser emission was studied experimentally and theoretically. The observed temperature dependences of the luminescence Stokes shift and of the spectral linewidth evidence the essential role of disorder in the dynamics of the recombining excitations. The spatial and energy disorders can cause a localization of photocreated excitations supposedly in the form of excitons. Theoretical study of the exciton dynamics is performed via kinetic Monte Carlo simulations of exciton hopping and recombination in the manifold of localized states. Direct comparison between experimental spectra and theoretical calculations provides quantitative information on the energy scale of the potential fluctuations in (GaIn)(NAs) quantum wells. The results enable one to quantify the impact of annealing on the concentration of localized states and/or on the localization length of excitons in (GaIn)(NAs) quantum wells.
TL;DR: In this article, self-pulsation at 45 GHz repetition frequency has been demonstrated in 1.5µm single-section quantum dot Fabry-Perot semiconductor lasers without saturable absorber.
Abstract: Self-pulsation at 45 GHz repetition frequency has been demonstrated in 1.5 µm monolithic single-section quantum dot Fabry-Perot semiconductor lasers without saturable absorber. The mode-beating exhibits a narrow linewidth below 100 kHz, demonstrating high phase correlation between these modes. Such modelocked lasers open ways to low timing-jitter components for clock recovery or millimetre-wave generation in wireless transmission applications.