共查询到20条相似文献,搜索用时 890 毫秒
1.
Toda T. Reinhardt F. Martinet E. Kapon E. Nakano Y. 《Photonics Technology Letters, IEEE》1999,11(12):1530-1532
Distributed-feedback (DFB) lasers were fabricated by using strained InGaAs quantum-wire (QWR) arrays on V-grooved GaAs substrates as an active grating. After characterizing the luminescence from the QWRs and parasitic quantum wells (QWLs), a DFB laser cavity incorporating such a QWR array with its emission wavelength matched to the Bragg wavelength was designed and fabricated. The wavelength selectivity of the DFB cavity was found to strongly support the QWR emission, and DFB lasing from QWR gain up to 145 K has been achieved under pulsed current. The emission from the parasitic QWLs was suppressed by the DFB filtering and the loss induced by coupling to radiation modes. The DFB cavity was shown to be essential for obtaining lasing from QWRs on V-grooved substrates 相似文献
2.
Kapon E. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1992,80(3):398-410
Recent progress in the development of the concept and technology of semiconductor quantum wire (QWR) lasers is reviewed. In these quasi-one-dimensional structures, optical gain is provided by charge carriers that are quantum mechanically confined in two dimensions within wire-like active regions. These devices are expected to exhibit improved laser performance, including extremely low threshold currents (in the μA range), higher modulation bandwidth, narrower spectral linewidth, and reduced temperature sensitivity. QWR lasers would thus be particularly useful in applications involving densely packed laser arrays and monolithic integration of lasers with low-power electronics, including computer optical interconnects, optical computing, and integrated optoelectronic circuits. Approaches for fabricating these novel structures are reviewed, and recent successful demonstrations of lasing in semiconductor QWRs are described. Prospects for further progress in this area are also discussed 相似文献
3.
《Microelectronics Journal》1999,30(4-5):379-385
Extremely flat interfaces, i.e. effectively atomically flat interfaces over a wafer-size area were realized in GaAs/AlGaAs quantum wells (QWs) grown on (411)A GaAs substrates by molecular beam epitaxy (MBE). These flat interfaces are called as “(411)A super-flat interfaces”. Besides in GaAs/AlGaAs QWs, the (411)A super-flat interfaces were formed in pseudomorphic InGaAs/AlGaAs QWs on GaAs substrates and in pseudomorphic and lattice-matched InGaAs/InAlAs QWs on InP substrates. GaAs/AlGaAs resonant tunneling diodes and InGaAs/InAlAs HEMT structures with the (411)A super-flat interfaces were confirmed to exhibit improved characteristics, indicating high potential of applications of the (411)A super-flat interfaces. High density, high uniformity and good optical quality were achieved in (775)B GaAs/(GaAs)m(AlAs)n quantum wires (QWRs) self-organized in a GaAs/(GaAs)m(AlAs)n QW grown on (775)B GaAs substrates by MBE. The QWRs were successfully applied to QWR lasers, which oscillated at room temperature for the first time as QWR lasers with a self-organized QWR structure in its active region. These results suggest that MBE growth on high index crystal plane such as (411)A or (775)B is very promising for developing novel semiconductor materials for future electron devices. 相似文献
4.
M. Geiger F. Adler U. A. Griesinger H. Schweizer F. Scholz 《Microelectronics Journal》1997,28(8-10):903-908
A single nominally lattice matched GaInAs quantum well (QW)/quantum wire (QWR) structure was grown by metalorganic vapor phase epitaxy (MOVPE) in V-grooved InP substrates. Different Si02 etch masks with opening widths from 2 μm down to 200 nm (for application as second order DFB grating) were defined by optical and electron beam lithography. A damage-reduced wet chemical etching process enables the growth of the GaInAs QWs/QWRs without any InP buffer layer. In low temperature photoluminescence we found improved intensity for all wire structures prepared by this etching technique. A reduction of the period and opening width of the V-groove etch mask resulted in a optimized luminescence intensity ratio between QW and QWR. Decay times from time resolved luminescence measurements were compared to the decay times of wet or dry etched mesa wires before and after regrowth. The good optical properties of the GaInAs QWRs are encouraging for future application as a QWR-laser device. 相似文献
5.
6.
AlGaAs-GaAs quantum-wire (QWR) gain-coupled distributed-feedback (GC-DFB) lasers have been fabricated by a single metal-organic chemical vapor deposition growth step on 0.36-μm pitch V-groove arrays of GaAs. A record low-threshold current of 13 mA is achieved via DFB lasing from QWR gain at room temperature. The consistency of the photon energies of the lasing and the photoluminescence peaks from QWR, and about 4-nm-wide stopband with a large threshold gain difference observed in the near-threshold spectrum are presented as possible evidence for GC-DFB effects in these devices 相似文献
7.
AlGaAs/GaAs quantum wire lasers, with three quantum wires (QWRs) of almost identical physical size, have been fabricated by flow rate modulation epitaxy. Room temperature lasing from the ground state electron and heavy-hole (le-lhh) transition of the QWRs has been observed for the first time. Typical threshold currents of 6 mA and extremely minor wavelength shifts in emission spectra have been obtained 相似文献
8.
9.
We discuss in detail a new mechanism of nonlinearity of the light-current characteristic (LCC) in heterostructure lasers with reduced-dimensionality active regions, such as quantum wells (QWs), quantum wires (QWRs), and quantum dots (QDs). It arises from: 1) noninstantaneous carrier capture into the quantum-confined active region and 2) nonlinear (in the carrier density) recombination rate outside the active region. Because of 1), the carrier density outside the active region rises with injection current, even above threshold, and because of 2), the useful fraction of current (that ends up as output light) decreases. We derive a universal closed-form expression for the internal differential quantum efficiency /spl eta//sub int/ that holds true for QD, QWR, and QW lasers. This expression directly relates the power and threshold characteristics. The key parameter, controlling /spl eta//sub int/ and limiting both the output power and the LCC linearity, is the ratio of the threshold values of the recombination current outside the active region to the carrier capture current into the active region. Analysis of the LCC shape is shown to provide a method for revealing the dominant recombination channel outside the active region. A critical dependence of the power characteristics on the laser structure parameters is revealed. While the new mechanism and our formal expressions describing it are universal, we illustrate it by detailed exemplary calculations specific to QD lasers. These calculations suggest a clear path for improvement of their power characteristics. In properly optimized QD lasers, the LCC is linear and the internal quantum efficiency is close to unity up to very high injection-current densities (15 kA/cm/sup 2/). Output powers in excess of 10 W at /spl eta//sub int/ higher than 95% are shown to be attainable in broad-area devices. Our results indicate that QD lasers may possess an advantage for high-power applications. 相似文献
10.
Design and Fabrication of Low-Driving-Voltage Electroabsorption Modulators Operating at 40 Gb/s 总被引:1,自引:0,他引:1
In this paper, a design for low-driving-voltage InGaAlAs/InAlAs electroabsorption modulators (EAMs) operating at 40 Gb/s is described. The theoretical calculation clarified that the tensile-strained InGaAlAs/InAlAs multiquantum-well layers with thin wells provide large and steep extinction characteristics. This was experimentally confirmed. We modeled an EAM with a low-loss coplanar waveguide for both the input and output ports and designed an optimized core structure that assures a sufficient extinction ratio and electrical-to-optical bandwidth for 40-Gb/s operation, in terms of well number and core length. A fabricated device driven by a peak-to-peak voltage as low as 1.1 V shows a 3-dB bandwidth of over 50 GHz and an RF extinction ratio of 10 dB. Error-free operation at 40 Gb/s is confirmed. 相似文献
11.
V. Hornung F. Le Du C. Starck G. Gelly J.Y. Emery C. Chaumont A. Bodere C. Hache O. Le Gouziegou E. Derouin G. Michaud M. Matabon J.F. Vinchant D. Lesterlin 《Photonics Technology Letters, IEEE》1996,8(9):1136-1138
Ridge integrated laser modulator (ILM) devices were fabricated using a butt-coupling technology based on two-gas-source molecular-beam epitaxy. A complete stability evaluation was undertaken, including a reliability study on discrete lasers, discrete modulators, and integrated devices. High temperature, high current, and high voltage were applied for over 1900 h without significant evolution of the electrooptical characteristics. A functional aging test at the current corresponding to a 2-mW output power and the modulator bias necessary to reach the maximum extinction ratio was performed for more than 1500 h. The butt-coupling region does not affect the reliability of the integrated devices. 相似文献
12.
Johansson L.A. Getty J.T. Akulova Y.A. Fish G.A. Coldren L.A. 《Lightwave Technology, Journal of》2003,21(12):2968-2976
Sampled-grating distributed Bragg grating (SGDBR) laser-based widely tunable optical transmitters are investigated for application in high-performance analog links. More than 45 nm tuning range, 40 dB sidemode suppression ratio, and peak relative intensity noise below -153 dB/Hz is measured. SGDBR lasers integrated with semiconductor optical amplifiers and electroabsorption modulators (EAMs) are characterized with spurious free dynamic range of 125-127 dB/spl middot/Hz/sup 4/5/ over the wavelength tuning range. It is also shown how the modulation response of the EAM is affected by the optical power to limit the performance of the analog transmitter. 相似文献
13.
Jian-Jun He 《Photonics Technology Letters, IEEE》2007,19(5):285-287
A novel structure and mechanism for high-speed modulation of semiconductor lasers are proposed and analyzed. The modulator consists of an antiresonant cavity acting as a rear reflector of the laser. The change of the absorption coefficient in the modulator results in a change in the reflectivity of the rear reflector, and consequently the Q-factor, the lasing threshold, and the output power. An implementation structure and numerical results for a Q-modulated distributed feedback laser are presented. The monolithically integrated Q-modulated laser has potential advantages of high speed, low wavelength chirp, high extinction ratio, and high power efficiency 相似文献
14.
In view of applications to next-generation electronics based on quantum devices, this paper presents and discusses the results of a systematic study recently done by the authors' group on the growth conditions, characterization and device application of InP-based In0.52Al0.48As/In0.53Ga0.47As quantum wires and dots formed by selective M13E growth on mesa-patterned (001) InP substrates. First, selective MBE growth experiments of InAlAs/InGaAs wire and dot structures on patterned (001) InP substrates are discussed generally. Then, particular attention is paid to successful growth conditions and properties of (110) oriented InAlAs/InGaAs ridge quantum wires (QWRs), including the effect of misorientation of mesa stripes. Finally, device related issues such as successful surface passivation by a technique using a silicon interface control layer (Si ICL) and electronic transport characterization by QWR transistors are discussed. The QWR transistor exhibited excellent gate-controlled one-dimensional transport with the appearance of clear conductance oscillations near pinch-off, visible up to about 50K. 相似文献
15.
T Fleischmann J.M UlloaM Moran G.J ReesJ Woodhead M Hopkinson 《Microelectronics Journal》2002,33(7):547-552
We have studied InGaAs/GaAs quantum well (QW) lasers with an intracavity saturable absorber grown on (111)B GaAs. The effect of the built-in piezoelectric field, resulting from strained growth, on the gain/absorption spectra is modelled theoretically and measured experimentally. With the piezoelectric field opposing and exceeding the intrinsic field in our structure an externally applied reverse bias can be used to change the net-field in the well from forward to reverse via the flat-band condition. Changing the field in the QW of the passive section influences its absorptive behaviour, changing the light output characteristics. Large hysteresis loops in the light output versus current relation are observed which can be tailored by the applied bias. Additionally, the change in absorption with applied bias provides the possibility of integrated amplitude modulation, avoiding the direct modulation of the active section. An extinction ratio of −11 dB was measured when changing the bias at the absorber by 1 V. 相似文献
16.
J. Antoszewski K. J. Winchester A. J. Keating T. Nguyen K. K. M. B. D. Silva C. A. Musca J. M. Dell L. Faraone P. Mitra J. D. Beck M. R. Skokan J. E. Robinson 《Journal of Electronic Materials》2005,34(6):716-721
A monolithically integrated low-temperature micro-electro-mechanical systems (MEMS) and HgCdTe infrared (IR) detector technology
is introduced, implemented, and characterized. The ultimate aim of this project is to develop a MEMS-based optical filter,
integrated with an IR detector, that selects narrow wavelength bands within the short-wavelength IR (SWIR) region of the spectrum.
The entire fabrication process is compatible with two-dimensional IR focal plane array technology, and needs to be compatible
with a proposed electrically tunable MEMS filter based on a Fabry-Perot optical cavity. The fabricated device consists of
an HgCdTe SWIR photoconductor, distributed Bragg mirrors formed of Ge-SiO-Ge, a sacrificial spacer layer within the cavity,
and a silicon nitride membrane for structural support. Mirror stacks fabricated on silicon, identical to the structures that
will form the optical cavity, have been characterized to determine the optimum filter characteristics. The measured full-width
at half-maximum (FWHM) was 34 nm at the center wavelength of 1,780 nm with an extinction ratio of 36.6. Fully integrated filters
on HgCdTe photoconductors with a center wavelength of approximately 1,950 nm give a FWHM of approximately 100 nm, and a peak
responsivity of approximately 8×104 V/W. The experimental results are in good agreement with the optical model, which takes into account mirror reflectivity,
absorption within the cavity by the spacer material, and absorption by the silicon nitride support structure. 相似文献
17.
We present a general theoretical model for the optical differential gain in semiconductor lasers. The model describes self assembly quantum dots (QDs), self assembly quantum wires (QWRs) and single quantum-well lasers. We have introduced the inhomogeneous broadening due to size fluctuations in the assembly cases. At each dimensionality, we have considered the carrier populations in the excited states and in the reservoirs, where conduction and valence bands are treated separately. We show that for room temperature operation the differential gain reduction due to increased size inhomogeneity is more pronounced in QDs than in QWRs. We show this reduction to be smaller than the one-order reduction attributed to state filling in conventional dot and wire assemblies operating at room temperature. The integration prefactor coefficient of the differential gain in zero-dimensional cases exceed one- and two-dimensional coefficients only for low temperatures where the homogenous broadening is considerably smaller than the thermal energy. The differential gain of QDs, QWRs, and compressively strained single quantum-well lasers operating at room temperature and close to equilibrium is nearly the same. 相似文献
18.
Kambiz Abedi 《半导体学报》2012,33(6):064001-6
Electroabsorption modulators (EAMs) with negative chirp and very low insertion loss are numerically designed with asymmetric intra-step-barrier coupled double strained quantum wells (AICD-SQWs) based on InGaAlAs material. For this purpose, the electroabsorption coefficient is calculated over a range of wells layer strain from compressive (CS) to tensile (TS). The chirp parameter and insertion loss for TE input light polarization are evaluated from the calculated electroabsorption spectra, and their Kramers-Krönig transformed refractive index changes. The results of the numerical simulation show that the best range of left and right wells strain for EAMs based on AICD-SQWs with negative chirp and very low insertion loss are from 0.032% to 0.05% (TS) and -0.52% to -0.50% (CS), respectively. 相似文献
19.
In this paper, we proposed a novel scheme to realize the multiwavelength erbium-doped fiber lasers. By adding a length of dispersion shifted fiber (DSF) in the ring cavity, we can suppress the cavity mode competition resulting from homogeneous line broadening (HLB) effect. In addition, a comb filter based on fiber delay inter-ferometer (DI) is used for frequency selecting. To enhance the extinction ratio while maintaining the free space range (FSR), the proposed isolator-assisted double-pass DI is utilized into the laser cavity, and a stable 7-wavelength simultaneous lasing spaced at 21.5GHz is accordingly achieved with an extinction ratio of higher than 40 dB. The lasers are stable with a maximum power fluctuation per channel of less than 0.6 dB during an hour test. 相似文献
20.
《Optical Fiber Technology》2001,7(2):84-100
In this study, we review the characteristics of 10-Gb/s electroabsorption modulator integrated (EAMI) distributed feedback (DFB) lasers for long-haul optical transmission systems. The recent progress and issue of extinction ratio, chirp, and frequency response are described, which are important parameters to improve transmission performance. Except for the extinction ratio, frequency response and chirp characteristics are discussed further. The frequency response of packaged EAMI-DFB lasers has been improved using the novel impedance matching technique. The large signal chirp characteristics are calculated with varying bias voltage, facet reflectance, grating phase, and a coupling coefficient (κL) to predict the measured chirp characteristics. Finally, transmission performance (BER, eye margin, and eye opening penalty) is measured and estimated using the calculated chirp characteristics. 相似文献