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Quantum Electronics, IEEE Journal of

Issue 1 • Date Jan. 1989

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Displaying Results 1 - 18 of 18
  • Multistable fiber-optic Michelson interferometer with electrooptic feedback exhibiting 95 stable states

    Page(s): 3 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    The multistable behavior of a fiber-optic Michelson interferometer with electrooptic feedback using a piezoelectric phase modulator is investigated. A linear stability analysis of the third-order differential equation used to describe the system reveals the number of stable states increases with the ratio tau /T of the system time constant ( tau ) and the feedback delay time (T). In laboratory investigations 95 stable states were achieved with tau /T>50.<> View full abstract»

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  • Modal propagation within MQW waveguides

    Page(s): 6 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (461 KB)  

    The propagation of TE modes and TM modes within planar multiquantum waveguides with large numbers of wells and barriers is shown to exhibit markedly different behavior for the two polarization states. The solutions for these two modes are developed for an arbitrary number of N barriers, and zero- and first-order approximations in powers of 1/N are calculated for quantities of physical interest. A very high geometric birefringence is demonstrated.<> View full abstract»

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  • Theory and applications of band-aligned superlattices

    Page(s): 12 - 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (818 KB)  

    A general device concept based on the miniband junctions formed in superlattices is described. Just as heterojunctions play an important role in bulk semiconductor devices, the miniband junctions have potential applications for superlattice devices. In the band-aligned structures, the aligned minibands function as an energy filter, which ensures efficient injection of monoenergetic carriers, while the miniband offsets can block the carrier flow similarly to the band discontinuity in bulk heterostructures. By engineering the alloy composition, the layer width, the doping, and the applied electric field, several examples of band-aligned superlattices are analyzed for applications in miniband transport and intersubband transitions.<> View full abstract»

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  • Spatial hole burning effects in distributed feedback lasers

    Page(s): 20 - 30
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (887 KB)  

    The effects of spatial hole burning in a steady-state distributed feedback (DFB) laser are examined by numerically solving the coupled mode equations that describe the system. An approximate solution for the gain above threshold is derived and compared to the exact solution. It is shown that the self-induced grating that arises due to spatial hole burning significantly reduces the mode discrimination of index-coupled DFB lasers. This makes it difficult for these lasers to maintain single-longitudinal-mode behavior above threshold. However, it is found in addition that bulk-modulated (gain-coupled) DFB lasers do not lose their mode selectivity above threshold, indicating that these lasers may be better choices for narrow-linewidth operation.<> View full abstract»

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  • Analyses of mode partition and mode hopping in semiconductor lasers

    Page(s): 31 - 38
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    Mode power fluctuations in semiconductors laser due to mode partition and mode hopping are discussed. The power dropout probability P/sub e/ in the mode partition was measured for a wide range, 1.6*10/sup -6/> View full abstract»

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  • Design considerations for crossing channel switches

    Page(s): 47 - 53
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    Theoretical and experimental design considerations for single-mode-crossing switches at the wavelength of 1.32 mu m are presented. The dependence of extinction ratio on branch angle for the extended electrodes and the estimation of fabrication tolerances of the crossing channel structure are discussed. It is also shown that crossing channel devices required a precise control of fabrication parameters.<> View full abstract»

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  • Resonant second harmonic generation by a semiconductor quantum well in electric field

    Page(s): 54 - 60
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    Both single- and double-resonance operating regimes are analyzed, and the latter is found to enable very high conversion efficiencies of pump to harmonic if accompanied by quasiphase matching by periodic alternation of the field direction. The self-consistent procedure of level energies and wave function calculation is also described.<> View full abstract»

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  • Chirped pulse amplification of 300 fs pulses in an alexandrite regenerative amplifier

    Page(s): 61 - 66
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    The amplification of femtosecond dye laser pulses up to the 3.5-mJ level in an alexandrite regenerative amplifier is discussed. An expansion/compression system using diffraction gratings allows chirped amplification techniques to be used to produce peak powers upwards of 1 GW. Limitations in the chirped pulse amplification of ultrashort pulses due to intracavity dispersive elements are discussed.<> View full abstract»

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  • Theory of optical nutation in direct-gap semiconductors due to ultrashort resonant laser irradiation

    Page(s): 67 - 72
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (599 KB)  

    An analytical investigation of optical nutation in direct-gap semiconductors such as GaAs, InSb, and Hg/sub 1-x/Cd/sub x/Te based on the time-dependent perturbation technique is discussed. The crystals are considered to be irradiated by short pulsed moderate power near-resonant lasers producing significant density of optically-induced free electron-hole pairs. Incoherent dephasing mechanisms have been introduced phenomenologically into the coherent radiation-semiconductor interaction model. The theory, on application to the case of a specific crystal such as Hg/sub 1-x/Cd/sub x/Te with x=0.18 irradiated by a pulsed 10.6 mu m CO/sub 2/ laser, manifests distinctly the occurrence of ringing behavior in the transmitted intensity, transient dispersion, and absorption even in the absence of any theoretical averaging or the consideration of the effective density of states.<> View full abstract»

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  • Simulations of a ring resonator free-electron laser

    Page(s): 73 - 83
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1067 KB)  

    A relatively high gain ( approximately=25 to 40%) free-electron laser (FEL) with an optical ring resonator is simulated using the code FELEX. The laser system corresponds to the 'burst mode' FEL. The ring consists of paraboloids, grazing incidence hyperboloids, and a grating rhomb. The wiggler is 5 m in length and has an adjustable taper, while the electron beam is produced by an RF linac. The optical elements of the ring together with the FEL interaction in the wiggler are modeled in three spatial dimensions to investigate the system from start-up to saturation. Both single-frequency and finite-pulse simulations are performed.<> View full abstract»

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  • An ultraviolet gas-loaded free-electron laser

    Page(s): 84 - 87
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (457 KB)  

    By loading the wiggler cavity of a free-electron laser (FEL) with hydrogen gas, it is possible to tune the FEL to below 130 nm, just above the electronic resonance of molecular hydrogen. The change in wavelength results from the refractive index of the gas, which alters the phase velocity of the wave and so modifies the synchronism condition. Using the parameters of the wiggler on the beamline of the Stanford Superconducting Accelerator, this FEL can be tuned from 500 to 130 nm with a pressure ranging from 0 to 55 torr. The calculated electronic gain varies between 5.6 and 11% over this wavelength interval, comparable to the gain in vacuum.<> View full abstract»

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  • Fluorescence dynamics of Er/sup 3+/ and Ho/sup 3+/ ions and energy transfer in some fluoride glasses

    Page(s): 88 - 96
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (679 KB)  

    A detailed study at room temperature of the fluorescence dynamics of Er/sup 3+/ and Ho/sup 3+/ ions and energy transfer processes Er/sup 3+/ to Ho/sup 3+/ in the ABLA, BATY, and BIZYT fluoride glasses is reported. Numerous concentrations and different selective laser excitations in the visible and infrared spectral ranges are used. The best concentrations and the more suitable glasses for laser applications at 2 mu m are determined.<> View full abstract»

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  • Observation of ultrafast nonlinear polarization switching induced by polarization instability in a birefringent fiber rocking filter

    Page(s): 104 - 112
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1032 KB)  

    Ultrafast all-optical switching between two orthogonal linear polarizations in a periodically twisted fiber filter is discussed. The dependence of the switching characteristics on the input power and operating wavelength is considered.<> View full abstract»

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  • Theoretical analysis of transient gain phenomena in a fast-axial flow type CO/sub 2/ laser amplifier

    Page(s): 121 - 131
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (911 KB)  

    A decrease of output power observed after discharging plasma tubes in a fast-axial flow CO/sub 2/ laser amplifier with a short dwell time of about 1 ms is discussed. For the 10P(18) line at 50 torr pressure, the small-signal gain goes from 1.308/m to 1.068/m within 135 s after discharging the plasma tubes, for a gas-flow velocity of 180 m/s and discharge current of 60 mA. The fraction of power decrease is about 15% for the plasma length of 80 cm and the input power of 5 W. Dependences of the observed fraction of power-down and the transient time to reach a stable power on input power and plasma length are theoretically analyzed by introducing the CO/sub 2/ dissociation factor as a function of gas-flow velocity, discharge current and plasma length, and gain saturation, resulting in good agreement between the experimental results and computation.<> View full abstract»

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  • Comments on `Interaction of carbon dioxide laser radiation with ocular tissues' by T.J. Bridges et al

    Page(s): 132 - 133
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    Previous experiments by Bridges et al. (in D.B. Karlin, 1984) on the interaction of carbon dioxide laser radiation with human eye lens tissue have been repeated. Contrary to previous results, it is found that there is a threshold fluence for the vaporization of lens tissue for its phototransection. Its average value is found to be about 26 J/cm 2 for 10.6-μm radiation. Beyond this threshold fluence, the depth of incision increases with the interaction time of the laser beam. The possibility of thermal dissolution of cataractous eye lens tissue is explored and it is shown that with the CO2 laser this is a high-temperature (270°C) process, which makes it impractical for the removal of cataracts View full abstract»

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  • Increase in laser repetition rate by spectral selection

    Page(s): 97 - 103
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    An experimental and theoretical study into the use of Fabry-Perot etalons as static repetition rate upconverters outside the laser cavity is discussed. It is shown that the output repetition rate can be increased up to 12 times while maintaining high average power View full abstract»

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  • A theoretical analysis of the transient intensity noise of semiconductor lasers

    Page(s): 39 - 46
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (556 KB)  

    The nonstationary intensity noise of a high-speed modulated semiconductor laser is investigated. The analysis is based on a rate equation method with Langevin fluctuation sources. The variance and the autocorrelation function of the intensity noise are calculated analytically with a state-space approach. The time-variant statistical properties of the intensity noise are evaluated numerically for the turn-on transient. The numerical calculation indicates that the difference between intensity noise and photon number fluctuations during the turn-on transient can be neglected. It a shown that is significant part of the nonstationary intensity noise can be described as timing jitter of the relaxation oscillations View full abstract»

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  • 50 J discharge-pumped XeCl laser

    Page(s): 113 - 120
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    An X-ray preionized XeCl laser with a wide aperture of 10×10 cm2 is described. The density for preionization electrons is estimated from an X-ray energy distribution to be greater than 6×109 cm-3 under operational gas conditions. In high pressure operation at 4500 torr, sufficient preionization has led to successful discharge-breakdown at a low E/N of 6.4×10-17 V-cm2, resulting in a high electrical efficiency of 3.1% with an output energy of 17.6 J. An output energy of 50 J in an 85-ns (FWHM) optical pulse has been extracted from an active volume of about 10:1 for a pulse-forming-line (PFL) voltage of 400 kV. The effects of impedance transformation of a pulse-transmission-line (PTL) following the PFL have been investigated using two types of PTL with output impedances of 0.26 and 0.48 Ω View full abstract»

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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