Scheduled System Maintenance:
On Monday, April 27th, IEEE Xplore will undergo scheduled maintenance from 1:00 PM - 3:00 PM ET (17:00 - 19:00 UTC). No interruption in service is anticipated.
By Topic

Quantum Electronics, IEEE Journal of

Issue 9 • Date Sept. 1997

Filter Results

Displaying Results 1 - 23 of 23
  • Corrections to "Theoretical And Experimental Investigations Of Small-signal Gain For A Diode-pumped Q-switched Cr:LiSAF Laser"

    Publication Year: 1997 , Page(s): 1614
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (17 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of integrated quantum-well infrared photodetector and light-emitting diode for implementing pixelless imaging devices

    Publication Year: 1997 , Page(s): 1527 - 1531
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (168 KB)  

    The conversion of images into nonuniform distribution of the output current density in a multiple-quantum-well structure for an infrared pixelless imaging system is considered using an analytical device model. The nonuniform current, which reproduces the incident image, is converted back to a light-emitting diode emission image by the device considered here. The developed model takes into account transport processes responsible for the device operation. An explicit expression for the contrast transfer characteristic is derived as a function of the number of quantum wells (QWs) and the electron capture parameter. It is shown that the quality of the up-converted images (contrast and resolution) is improved with increasing number of QWs. The pixelless imaging devices under consideration can effectively convert long-wavelength infrared images into short-wavelength infrared or visible images with contrast transfer ratio close to unity View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electroabsorption and electrooptic effect in SiGe-Si quantum wells: realization of low-voltage optical modulators

    Publication Year: 1997 , Page(s): 1532 - 1536
    Cited by:  Papers (8)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (124 KB)  

    We have calculated the behavior of the band-to-band absorption coefficient in square, coupled, and graded bandgap Si0.6Ge 0.4-Si quantum wells as a function of the transverse electric field. It is seen that due to the weak confinement of the electrons (ΔEc⩽20 meV) the absorption of photons with energy equal to the interband transition energy can be reduced at very small values of the transverse electric field. This phenomenon lends itself to the design of efficient amplitude modulators. In addition, the resulting change in the refractive index is also large and the corresponding linear electrooptic coefficient is calculated to be as large as 1.9×10-10 m/V in square wells. This effect could prove to be the basis for the realization of efficient Si-based electrooptic modulators. Device designs are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Determination of the wavelength dependence of Auger recombination in long-wavelength quantum-well semiconductor lasers using hydrostatic pressure

    Publication Year: 1997 , Page(s): 1557 - 1566
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (268 KB)  

    The variation of the threshold current of an unstrained 1.48-μm InGaAsP quantum-well (QW) laser has been measured as a function of hydrostatic pressure up to 27 kbar. We combine this result with theoretical calculations to extract the bandgap dependence of the Auger coefficient, C, over a range of 200 meV. We find that over this range C reduces by a factor of about three. We have calculated the bandgap dependence of the main Auger processes and conclude that the dominant Auger process over this wavelength range could either be the phonon-assisted CHCC process or the band-to-band CHSH process. Based on this result, we have estimated the threshold current density of strained and unstrained lasers with wavelengths ranging from 1.75 to 1.3 μm using both these processes. We get good agreement between theory and experiment in both cases and show that Auger recombination is the dominant current contribution in 1.5- and 1.3-μm devices View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Injection-locked semiconductor lasers with delayed optoelectronic feedback

    Publication Year: 1997 , Page(s): 1582 - 1591
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (380 KB)  

    Optical injection and optoelectronic feedback are efficient techniques to externally control the spectral characteristics of a semiconductor laser. This paper presents theoretical and experimental results about the effects of a delayed optoelectronic feedback loop on the stability of an optically injected diode laser. In particular, negative feedback configurations (out-of-phase carrier reinjection) are shown to widen the injection-locking domain of the laser and reduce its unstable region. On the contrary, in positive feedback configurations (in-phase carrier reinjection), the laser diode generates a modulation with tunable multigigahertz frequency View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quantitative nonlinear spectroscopy: a direct comparison of degenerate four-wave mixing with cavity ring-down spectroscopy applied to NaH

    Publication Year: 1997 , Page(s): 1465 - 1473
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    Cavity ring-down spectroscopy and degenerate four-wave mixing have been applied for spectroscopic studies, temperature determination, and measurement of relative dipole transition moments of photochemically produced sodium hydride. In our experiment, NaH was formed within a heat-pipe oven after 3p excitation of sodium in a hydrogen atmosphere with a second dye laser. The reaction product NaH was probed in the near ultraviolet part of the spectrum at 382 nm with 1-4-μs delay to the excitation pulse using both a linear and nonlinear spectroscopic technique with a pulsed dye laser source (pulsewidth 15-ns full-width half-maximum). The strengths and limitations of these two spectroscopic techniques are discussed. Since the two processes depend on different parameters and the image-forming beams have different properties, it is difficult to define a single criterion for comparison. But our measurements indicate that cavity ring-down spectroscopy is a powerful tool with a sensitivity better than 109 particles per cm3 and quantum state which is comparable to degenerate four-wave mixing in our case View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fiber transmission for sub-500-fs pulses using a dispersion-compensating fiber

    Publication Year: 1997 , Page(s): 1455 - 1464
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    We report transmission of ~60-fs and ~245-fs pulses, respectively, over 42-m and 2.5-km fiber links which consist of standard single-mode fibers (SMF) concatenated with dispersion-compensating fibers (DCF). The experiments using very short pulses (~60 fs) over a short fiber length (~42 m) demonstrate the ability to achieve simultaneous dispersion and dispersion slope compensation using this technique. Femtosecond spectral interferometry measurements of this 42-m link show that its residual dispersion slope is approximately six times lower than that of the dispersion-shifted fiber. Finally, to demonstrate that the dispersion-limited propagation distance is proportional to the cube of the pulsewidth, we transmit ~245-fs pulses over a 2.5-km SMF-DCF link and achieve comparable pulse restoration as with the shorter fiber experiments View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Frequency dynamics of gain-switched injection-locked semiconductor lasers

    Publication Year: 1997 , Page(s): 1537 - 1542
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB)  

    The frequency dynamics of gain-switched single-mode semiconductor lasers subject to optical injection is investigated. The requirements for low time jitter and reduced frequency chirp operation are studied as a function of the frequency mismatch between the master and slave lasers. Suppression of the power overshoot, typical during gain-switched operation, can be achieved for selected frequency detunings View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Long-wavelength (9.5-11.5 μm) microdisk quantum-cascade lasers

    Publication Year: 1997 , Page(s): 1567 - 1573
    Cited by:  Papers (36)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (188 KB)  

    Quantum-cascade whispering-gallery-mode disk lasers emitting at 9.5-μm and 11.5-μm wavelength are reported. Taking advantage of the high-quality resonator (Q≈200), the threshold current density of disk lasers emitting at 9.5 μm is reduced below the value of the corresponding ridge waveguide geometry (Jth,disk=2.39 kA.cm -2 versus Jth,ridge=3.0 kA.cm-2). Additionally, the increase in wavelength compared to previously reported disk lasers at 5.0 μm is a significant step toward the microcavity regime (by an effective scaling factor of 2.5, comparing identical disk sizes), disk diameters from 125 μm down to 20 μm are used to study the approach to the microcavity regime by size reduction. Far-field pattern measurements identify scattering from the pedestal as an important outcoupling mechanism for microdisk lasers. An excellent agreement between the measured and calculated free spectral range of the whispering gallery modes allows us to estimate the beta factor of the microdisks, resulting in β≈0.05 for a 20-μm diameter disk. A two-level rate equation model is evaluated for the quantum-cascade disk laser as a tool for a direct measurement of β. Nevertheless, the actual measurement is at present blurred by luminescence (light-emitting diode) from the disk center accompanied by an unbalanced carrier distribution between the whispering gallery laser and the center light-emitting diode View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A model of the metallic surface-emitting second harmonic generator

    Publication Year: 1997 , Page(s): 1474 - 1480
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (252 KB)  

    We present an accurate calculation of the intensity of the second harmonic radiation generated by the reflection of the incident radiation from a metal surface. This radiation is due to two currents. The first current results from the rapid variation of the normal component of the oscillating electric field in the vicinity of the surface and depends on both conduction and bound electrons. The second one results from the action of the Lorentz force on conduction electrons. We show that if the adiabatic and the Thomas-Fermi assumptions are considered, then an accurate calculation of these currents is possible and leads to a simple relation of the intensity of the second harmonic radiation View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 115-W Tm:YAG diode-pumped solid-state laser

    Publication Year: 1997 , Page(s): 1592 - 1600
    Cited by:  Papers (66)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (212 KB)  

    A compact diode-pumped Tm:YAG laser capable of generating greater than 100 W of CW power at 2 μm has been demonstrated. A scalable diode end-pumping architecture is used in which 805-nm radiation, coupled to the wing of the Tm3+3H6-3H 4 absorption feature, is delivered to the end of the laser rod via a lens duct. To facilitate thermal management, undoped YAG end caps are diffusion bonded to the central doped portion of the laser rod. For 2% and 4% Tm-doped rods of the same length, the lower doping level results in higher power, indicating that cross relaxation is still efficient while offering lower thermal stress and reduced absorption at the laser wavelength. Output powers for various output coupler reflectivities are compared to the predictions of a quasi-three-level model. Thermal lensing, cavity stability, and stress-induced birefringence measurements are described. The beam quality was analyzed with the 2% Tm-doped rod and a flat output coupler, yielding M2 values of 14-23 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Eigenvalue equations of N-parallel graded-index waveguides: WKB analysis

    Publication Year: 1997 , Page(s): 1608 - 1613
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    The eigenvalue equations of N-parallel graded-index waveguides are derived in a recursive form for the first time by using the WKB method and the transfer matrix method. For the derivation, trial solutions are defined which not only converge at turning points but also approximate the conventional WKB solutions. It is confirmed through the computer simulation that the results of the derived WKB eigenvalue equations are in good agreement with those of the finite-difference method in the well-guided regions View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The 2-D-3-D crossover in modulation-doped GaAs-Ga1-xAl xAs quantum wells

    Publication Year: 1997 , Page(s): 1492 - 1497
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB)  

    We report on a method to analyze the 2-D-3-D crossover in n-type modulation-doped quantum wells. Finite well barrier, first and second subband population, many-body effects, and residual doping are included in our calculation. We found that the 2-D-3-D crossover remarkably depends not only upon the geometrical parameters, as for instance, the spacer layer width and quantum-well width, but also upon a residual p-type doping intentionally introduced. A diagram showing the 2-D-3-D dimensional crossover is presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurement of effective drift velocities of electrons and holes in shallow multiple-quantum-well p-i-n modulators

    Publication Year: 1997 , Page(s): 1498 - 1506
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    We present results on carrier transport in shallow multiple-quantum-well GaAs-AlxGa1-xAs p-i-n diodes (x=0.02, 0.04, 0.08) at various bias voltages. We show that only carrier drift and enhanced diffusion dominate response times of these devices. We also emphasize that the drift of holes plays different roles in determining the response times: at low bias, the slow drift of holes adds to enhanced diffusion, slowing down the decay-times; at high bias, the drift time of holes can be comparable to the time of electrons and contribute to the rise-times. From picosecond time-resolved pump/probe electroabsorption measurements, we obtain the drift times, effective drift velocities, and effective mobilities of electrons and holes. The effective drift velocities (especially for holes) appear rather insensitive to the Al concentration in the barriers View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Monte Carlo simulations of carrier transport in AlGaInP laser diodes

    Publication Year: 1997 , Page(s): 1551 - 1556
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (124 KB)  

    A self-consistent ensemble Monte Carlo simulation of charge transport in AlGaInP quantum-well (QW) lasers has been developed in an effort to understand the temperature sensitivity of these devices. In particular, the lasing capability of a three-well design has been studied at 300 and 360 K. Although the electron and hole leakage currents are found to increase with the temperature, this does not explain a reduction in the emitted light hole emission time intensity for the particular device studied. Instead, the fall in the light output is due to increased emission from the QW's, since this reduces the net electron and hole capture efficiency View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of far-field patterns of microdisk resonators by the finite-difference time-domain method

    Publication Year: 1997 , Page(s): 1489 - 1491
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (132 KB)  

    The far-field patterns of microdisk resonators are analyzed by using the finite-difference time-domain (FDTD) method and the near-to-far field transformation. A brief summary of FDTD and details of the transformation in the cylindrical coordinate system are presented. Using FDTD, the wavelengths and Q values of the resonant modes are calculated from an impulse excitation. The steady-state field solutions are calculated from sinusoidal sources. The far-field patterns of an ideal microdisk are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Acoustooptic interactions in AlGaAs-GaAs planar multilayer waveguide structures

    Publication Year: 1997 , Page(s): 1601 - 1607
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (156 KB)  

    The acoustooptic interaction of guided optical waves and surface acoustic waves (SAW's) is studied in multilayered structures of dimensions of the order of those seen in multiple-quantum-well (MQW) structures. The guided mode profiles and SAW-induced electric field and strain profiles are used to calculate the diffraction efficiency, using an expression derived from coupled mode theory. Diffraction efficiency is plotted as a function of SAW frequency, and the effects of acoustic power, acoustic aperture, and material structure are considered. For a specific structure, the diffraction efficiency is seen to increase with increasing aluminum content for low concentrations and the opposite is seen for higher concentrations. This is explained in terms of the opposing effects of guided optical mode parameters and material properties. Possibilities for optimization of the diffraction efficiency through tailoring of the refractive index profile of the material structure are suggested View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effective Bloch equations for semiconductor lasers and amplifiers

    Publication Year: 1997 , Page(s): 1543 - 1550
    Cited by:  Papers (52)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (180 KB)  

    A set of effective Bloch equations is established for semiconductor bulk or quantum-well media. The model includes the nonlinear carrier-density dependence of the gain and refractive index and their respective dispersions (frequency dependences). A comparative study is performed between the full microscopic semiconductor Bloch equations and this effective model for pulse propagation to show the range of validity of the present model. The results show that this model agrees well with the microscopic model provided carrier depletion is the dominant saturation mechanism relative to the plasma heating. The effective Bloch equations provide an accurate and practical model for modeling amplifiers with pulses of duration greater than a few picoseconds. By capturing the large bandwidth and the carrier density dependence of the gain, it also provides a reliable model for studying the complex spatiotemporal multilongitudinal and transverse mode dynamics of a variety of wide-aperture high-power semiconductor lasers. The model goes beyond the traditional rate equations and is computationally much more efficient to simulate than the full model View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The optical response of epitaxial lift-off HEMT's to 140 GHz

    Publication Year: 1997 , Page(s): 1507 - 1516
    Cited by:  Papers (6)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (212 KB)  

    We present measurements on the optical frequency response of epitaxial lift-off (ELO) 1.0-μm InP high-electron mobility transistors (HEMTs) to 140 GHz using electrooptic sampling and heterodyne techniques. Our picosecond sampling measurements established that the lift-off devices exhibited substantial optical response to 140 GHz. Heterodyne measurements made at 60 and 94 GHz later confirmed these findings. A novel three wave mixing technique was used to extend the heterodyne bandwidth to 130 GHz. In these experiments, millimeter waves were generated in our optically driven HEMT's and launched into waveguides. These lift off devices can be major additions to future millimeter wave integrated optoelectronic systems either as high frequency optical detectors or as optically driven tunable millimeter wave sources View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microcavity effects in an external-cavity surface-emitting laser

    Publication Year: 1997 , Page(s): 1574 - 1581
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (264 KB)  

    Microcavity-induced lasing threshold reduction and modulation of the spontaneous emission coherence length with cavity length in an external-cavity resonant-periodic-gain, surface-emitting laser is reported. In contrast to comparing different epitaxial growths, external-cavity operation allows changing the cavity length without affecting material properties as well as arbitrarily long resonator lengths. The transition to the macrocavity domain is observed by extending the cavity length beyond the spontaneous emission coherence length. The maximum change in the spontaneous emission rate induced by the cavity QED effect in the presence of resonant periodic gain is calculated. As expected, for cavities longer than several wavelengths, microcavity Fabry-Perot resonance effects dominate over cavity QED in determining the cavity-normal spontaneous emission power and coherence length. A simple model of the cavity-normal spontaneous emission coherence length and spontaneous emission power emitted from a Gaussian source placed in an ideal Fabry-Perot cavity is consistent with our observations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Noise in an optical amplifier: formulation of a new semiclassical model

    Publication Year: 1997 , Page(s): 1481 - 1488
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (300 KB)  

    After pointing out some questionable assumptions of the standard beating theory, we formulate a new semiclassical wave theory of the noise in optical amplifiers. The theory is simple yet rigorous and uses a few quantum statements in a classical signal framework. The amplifier is modeled as a 2×2 port device, and the amplified spontaneous emission and associated noise are shown to be just the amplified coherent state (or vacuum state) fluctuation of the field entering the idler input. The new theory can treat other closely related detection schemes as well, correctly supplying both mean signal and noise View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Synchronization of chaotic lasers by optical feedback for cryptographic applications

    Publication Year: 1997 , Page(s): 1449 - 1454
    Cited by:  Papers (42)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (172 KB)  

    We propose a new scheme for synchronization of the optical chaos generated by a semiconductor laser subjected to external reflection. The scheme is based on optical feedback and will be analyzed from the viewpoint of static and dynamic properties and of robustness to external perturbations and noise. An application to cryptographic communications (chaotic shift keying) is finally proposed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quantum interference, Stark, and carrier density infrared electrooptical modulation based on intersubband transitions in asymmetrical quantum wells

    Publication Year: 1997 , Page(s): 1517 - 1526
    Cited by:  Papers (8)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB)  

    A new approach toward studying electrooptic modulation utilizing intersubband transitions in quantum wells is presented. Using first-order perturbation theory for analyzing the effect of a dc electric field on the linear susceptibility, an understanding of the mechanisms which give rise to intersubband electrooptic susceptibility is presented. This includes modulation due to the dc Stark effect, modulation due to coherent interference of the envelope states, and modulation of the carrier densities in populated subbands. We study several structures that maximize the electrooptic susceptibility of a particular origin and discuss the suitability of the various schemes for practical realizations. Finally, we derive a figure of merit for each type of modulator, taking into account the linear intersubband absorption, and show that highly efficient near-infrared modulators that operate at a wavelength of 1.5 μm can be realized View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The IEEE Journal of Quantum Electronics is dedicated to the publication of manuscripts reporting novel experimental or theoretical results in the broad field of the science and technology of quantum electronics..

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Aaron R. Hawkins
Brigham Young University