Scheduled System Maintenance:
Some services will be unavailable Sunday, March 29th through Monday, March 30th. We apologize for the inconvenience.
By Topic

Quantum Electronics, IEEE Journal of

Issue 1 • Date Jan. 1996

Filter Results

Displaying Results 1 - 22 of 22
  • Correction to "Upconversion Pumped Thulium-Doped Fluoride Fiber Amplifier and Laser Operating at 1.4

    Publication Year: 1996
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (58 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.
  • Mechanisms of fast self pulsations in two-section DFB lasers

    Publication Year: 1996 , Page(s): 69 - 78
    Cited by:  Papers (51)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1132 KB)  

    We show theoretically, that the detuning between the resonance frequencies of differently pumped DFB sections gives rise to two different pulsation mechanisms, 1) dispersive self Q-switching of a single-mode and 2) beating oscillations between two modes of nearly equal threshold gain. Our analysis is based on the dynamic coupled wave equations accomplished with carrier rate equations. We demonstrate the existence of certain isolated values of the detuning between both sections, at which two longitudinal eigenmodes become degenerate. In the degeneration point, the longitudinal excess factor of spontaneous emission has a singularity and the system of eigenmodes becomes incomplete. We derive reduced equations governing the dynamics in the vicinity of degeneration points. For an example device, the numerical integration of these equations clearly demonstrates the two different self pulsations with repetition rates of more than 100 GHz View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Carrier induced transient electric fields in a p-i-n InP-InGaAs multiple-quantum-well modulator

    Publication Year: 1996 , Page(s): 43 - 52
    Cited by:  Papers (7)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (908 KB)  

    Low-power time-resolved pump-probe measurements made on a InP-In 0.53Ga0.47As p-i-n multiple-quantum-well optical modulator are presented. The results show a nonzero signal at negative delays whose magnitude and sign exhibit a strong dependence upon the wavelength and bias. The overall behavior after zero delay, in particular the signal rise and fall times, also depends strongly upon these parameters. A theory, based upon electric field variations due to carrier motion in the intrinsic region of the device, is developed to explain the results. It is found that the signal at negative delay is due to hole space charge trapped in the quantum wells, while the fast effects after zero delay are due to the rapid emission of electrons which cause a temporary reduction in potential across the device. This is followed by diffusive conduction within the contact layers which restores the potential to its former value. The rich variety of signal responses is attributed to transient Stark shifts which vary greatly with well position due to the nonuniformity of the dynamic change in the electric field. Calculated signal responses are in excellent agreement with the experimental results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Monolithic integration of InGaAsP-laser with transferred-electron device as fast laser driver

    Publication Year: 1996 , Page(s): 14 - 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB)  

    A monolithically integrated laser driver circuit has been fabricated incorporating an InGaAs-transferred electron device (TED) and an InGaAsP mushroom stripe laser emitting at 1.3-μm wavelength. The TED provides a large-signal modulation of the laser diode along with a pulse shaping of the optical output signal. A threshold current of 18 mA of the integrated laser has been obtained. The modulation of the optical output signal by the TED has been demonstrated. For practical application of the circuit under dc-bias conditions the thermal resistance of the TED's has been calculated and an optimum device structure is proposed. The possibility of triggering the circuit optically will be discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 1047-nm master oscillator power amplifier free-space optical communications laser transmitter

    Publication Year: 1996 , Page(s): 112 - 117
    Cited by:  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    We report on the performance of a 1047-nm laser diode master oscillator (MO) diode pumped Nd:YLF power amplifier (PA) laser transmitter in a 50-Mbps quaternary pulse position modulation (Q-PPM) free-space optical direct detection communications experiment. The transmitter produced greater than 1 W of 1047-nm average optical power. At optical transmitter powers up to 0.2 W, we achieved nearly the same communications performance (~210 photons/b at 10-6 bit-error rate) using the 1047-nm MOPA transmitter as with the 50 mW laser diode alone. We relied on an external-cavity grating feedback scheme for the 1047-nm laser diode MO to achieve this communications performance View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Evolution of the intensity profile of Cerenkov second-harmonic radiation with propagation distance in planar waveguides

    Publication Year: 1996 , Page(s): 137 - 144
    Cited by:  Papers (5)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB)  

    Using coupled mode theory, we have studied the output intensity profile of Cerenkov second-harmonic radiation from planar waveguides as a function of the propagation distance. In particular, we have obtained the variation of the intensity profile taking into account the effect of prism coupling as well as propagation loss, and have shown that the second-harmonic radiation evolves into a beam-like output. Results of the measured intensity profile of the second-harmonic radiation in proton-exchanged planar waveguides in Z-cut LiNbO3 are also presented that are consistent with the theory View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Theoretical investigation on semiconductor lasers with passive waveguides

    Publication Year: 1996 , Page(s): 4 - 13
    Cited by:  Papers (7)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (936 KB)  

    Semiconductor lasers with vertically integrated passive waveguides are theoretically studied using the coupled mode theory and exact calculation. Formulas for the threshold current density and the far-field patterns are derived. The physical concepts of the modulation of the beam divergence by passive waveguides are given. The exact calculated results show that the beam divergence can be greatly improved by paying a price of only a slight increase of the threshold current density. The operation mode selection is discussed. Attention is also paid to the appearance of side lobes for very narrow far-field patterns. Discussions are given for device design View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Creation and optimization of vertical-cavity X-modulators

    Publication Year: 1996 , Page(s): 53 - 60
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (836 KB)  

    We have developed a photon conserving, reversible optoelectronic intensity modulator. The device works by using quantum wells in a slightly asymmetric InGaAs-AlGaAs QW Fabry-Perot cavity to direct an incident optical beam to transmit through the device or to be reflected from the device depending upon the state of the switching element. The first experimental device simultaneously switches reflectivity and transmission from 6% to 60% and 60% to 6%, respectively. We also examine the cavity design parameter space and effects of incident angle on device performance. Furthermore, experimental results from combinations of stacked devices are discussed. A theoretical analysis of the X-modulator design parameter space is given as is an analysis of the system response of our two element stacked devices. Finally, a thorough theoretical treatment of crossbar switches using symmetric X-modulators is provided View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Barrier composition dependence of differential gain and external differential quantum efficiency in 1.3-μm strained-layer multiquantum-well lasers

    Publication Year: 1996 , Page(s): 38 - 42
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    Dependence of the differential gain and the external differential quantum efficiency on the composition of InGaAsP barrier layers were investigated for 1.3 μm InGaAsP-InGaAsP compressively strained layer (SL) multiquantum well (MQW) lasers. In this investigation, we compared between SL-MQW lasers and unstrained MQW lasers having the same well thicknesses and the same emitting wavelength in order to clarify the effect of strain for each barrier composition. As a result It has been found that the barrier composition has large influence on the differential gain and the external differential quantum efficiency in the SL-MQW lasers. Narrower band-gap barrier means little effect of strain on the differential gain due to the electron overflow from a well layer, while wider band-gap barrier means degradation in the differential gain and the external differential quantum efficiency due to the nonuniform injection of hole into a well layer. In this experiment, the barrier composition of 1.05 μm is suitable for 1.3 μm InGaAsP-InGaAsP SL-MQW lasers to realize large differential gain and high external differential quantum efficiency simultaneously View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ho:Tm lasers. I. Theoretical

    Publication Year: 1996 , Page(s): 92 - 103
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1252 KB)  

    Energy transfer dynamics pertinent to Ho:Tm lasers are modeled in two steps: a calculation of the parameters controlling the energy transfer process and a calculation of the population densities of all manifolds influencing the laser process. Energy transfer parameters are modeled with the classical dipole-dipole approximation, but several important changes are implemented to better describe laser materials such as Ho:Tm laser materials. This approach was used to calculate energy transfer parameters using measured energy levels coupled with quantum mechanical calculations although spectroscopically measured parameters could be used in principle. Given the energy transfer parameters, a rate equation approach is used with the eight manifolds required for an accurate description of the Ho:Tm laser. Population densities of all eight manifolds can be predicted as a function of time whether or not lasing occurs. Results of the modeling process are compared with experimental results for both Ho:Tm:YAG and Ho:Tm:YLF with different concentration and a variety of different mirror reflectivities and different pump pulse lengths in a companion paper View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of double and triple quantum wells for InGaAs-AlAsSb intersubband unipolar semiconductor lasers

    Publication Year: 1996 , Page(s): 20 - 28
    Cited by:  Papers (11)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (720 KB)  

    InGaAs-AlAsSb double and triple quantum well (QW) structures were designed in an effort to shorten the wavelength to less than 2 μm for possible application to intersubband unipolar lasers. Wavelengths corresponding to the intersubband separation, the minimum and maximum operating electric field, optical-phonon-limited nonradiative scattering time, and escape time from the QW were simulated. It was found that suitable nonradiative transition times can be obtained by properly designing the coupling layer thickness for both kinds of QW's. The minimum wavelength is 1.5 μm and an operating electric field is above 130 kV/cm for wavelengths <2 μm in the double QW. On the other hand, the minimum operating electric field is less than 10 kV/cm and the minimum wavelength is about 1.7 μm for the triple QW. The triple QW is suitable for an electric-field induced wavelength tunable laser View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Energy transfer up-conversion and excited state absorption of laser radiation in Nd:YLF laser crystals

    Publication Year: 1996 , Page(s): 79 - 91
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1196 KB)  

    Experiments at room temperature were carried out to study the higher order processes that produced the yellow and blue fluorescence observed in Nd:YLF laser crystals, which were pumped by lasers with wavelengths between 785 nm and 811 nm, and with the pump power density ranging from 10 to 30 kW/cm2, or the stored energy density, 15-45 J/cm3. The analysis of the experimental results provided an explanation for the performance degradation of a Q-switched laser with increasing pump intensity. These higher order processes were energy transfer up-conversion and excited state absorption of both pump and laser radiation. A model was also developed based upon rate equations to describe these higher order processes. This model allowed us to discriminate between these processes and to determine which one played the most important role. The experimental results agreed well with the predictions of the model. It is concluded that the energy transfer up-conversion process is the dominant mechanism for the population of the 4G7/2 multiplet. It is also concluded that excited state absorption of the 1.05 μm or 1.3 μm radiation from the 4G7/2 multiplet play a significant role in populating the 2P3/2, 2 D(1)5/2, and 2P½ manifolds, and in the performance of Nd:YLF lasers operating in the pulsed mode. The effect of excited state absorption of the pump radiation from the 4F½ multiplet is much less important View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Injection locking of a passively mode-locked laser

    Publication Year: 1996 , Page(s): 155 - 160
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB)  

    We present and analyze a model of a passively mode-locked laser, which is subjected to injection of a coherent pulse train. The model, based on soliton perturbation theory, predicts the possibility of coherent injection locking, and gives analytical estimates for the locking ranges. The ability to simultaneously lock the timing and the phase of the output pulses of a mode-locked laser to an injected, coherent pulse train is shown. The interesting limiting case of phase locking the mode-locked laser to a constant amplitude external injection, is addressed with implications for future coherent soliton communication systems View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tensile strain and threshold currents in GaAsP-AlGaAs single-quantum-well lasers

    Publication Year: 1996 , Page(s): 29 - 37
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (924 KB)  

    The effects of tensile strain on threshold current in GaAsP-AlGaAs quantum well lasers are studied theoretically and experimentally. A comprehensive model for the light-current characteristics of separate-confinement strained-layer lasers, which is based on a six-band Luttinger-Kohn valence dispersion model, is first developed. Theoretical and experimental results for broad stripe single-well laser diodes with a constant well width of 115 Å are then presented. Experimentally observed variations in threshold currents and TE/TM polarization switching are accurately described by the model for phosphorus compositions in the quantum-well ranging from 0 to 0.30 and cavity lengths ranging from 300 to 1500 μm. Constant-gain contours generated from the theoretical model are shown to provide a simple and powerful guide to various regimes of operation. Our studies show that tensile-strain-related effects lower threshold currents in GaAsP-AlGaAs only in the high gain (short cavity) regime, and suggest more generally that the threshold advantages offered by tensile strain are conditional View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Influence of lateral field on the relaxation oscillation frequency of semiconductor lasers

    Publication Year: 1996 , Page(s): 1 - 3
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB)  

    We demonstrate theoretically that the lateral field distribution can be utilized to enhance the relaxation oscillation frequency of semiconductor lasers. It is found, for some laser parameters, that gain-guided semiconductor lasers with narrow stripe can exhibit higher relaxation oscillation frequency than index-guided devices View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An analytical treatment of the effect of axial inhomogeneity on femtosecond solitary waves near the zero dispersion point

    Publication Year: 1996 , Page(s): 145 - 154
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (852 KB)  

    A perturbed nonlinear Schrodinger equation, valid for femtosecond pulse propagation in axially inhomogeneous optical fibers near the zero dispersion point, is considered. It is found that for a weak axial nonuniformity, and under certain conditions, this equation can be treated analytically. Exact bright and dark solitary wave solutions are derived and their behavior in the presence of the inhomogeneity is analyzed. The nonuniformity induced time shift of the solitary waves is also obtained. The potential use of this parameter as a diagnostic tool for estimating characteristic parameters of the axial variations is discussed and its range of values is investigated View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Space-time profiles of shaped ultrafast optical waveforms

    Publication Year: 1996 , Page(s): 161 - 172
    Cited by:  Papers (46)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1208 KB)  

    A derivation of the space-time profiles of ultrafast optical waveforms shaped by filtering of spatially separated frequency components is presented. Closed form expressions for the space-time impulse response functions are given for the cases of single and double passes through a pulse shaping apparatus. For a single pass and a short unshaped pulse, diffraction by the mask filter gives rise to a translational spatial shift in the desired electric field profile that varies linearly with time along the shaped waveform. This result is completely general, and applies to frequency-domain pulse shaping with either continuous or discrete mask filters. It is also shown that double passing the apparatus does not generally reverse this effect but rather introduces further space-time coupling such as a time-varying spotsize. Examples of specific mask patterns are presented and implications for the generation of high-fidelity shaped optical waveforms are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Static and dynamic analysis of tunable two-section high-speed distributed feedback laser utilizing the gain lever effect

    Publication Year: 1996 , Page(s): 61 - 68
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (712 KB)  

    Analysis of a novel semiconductor laser structure designed for obtaining wide tuning range along with high speed modulation response is presented. The laser consists of a composite cavity structure with two active (gain) sections. One of the sections has a grating corrugation while the other is flat. A detailed round-trip analysis is combined with the rate equations, which include sublinear gain/carrier relation, to perform steady-state and small-signal analysis. It is shown that the biasing (dc) condition of the different sections plays a critical role in the determination of the dynamic response of the device. In addition, we show that the gain-lever effect can be utilized for a considerable enhancement of the frequency modulation (FM) response. Other critical structural parameters such as the grating coupling coefficient and device geometry are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Efficient third-harmonic generation of a picosecond laser pulse with time delay

    Publication Year: 1996 , Page(s): 127 - 136
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (860 KB)  

    A new configuration based on the polarization-mismatching scheme with time delay for efficient frequency tripling conversion is proposed in this paper. The calculated results showed that the requirement for the efficient frequency tripling conversion of a 1-ps laser pulse is not only the optimization of peak intensity of the second-harmonic pulse, but also the optimization of the pulse duration ratio and temporal difference between the o-polarization second-harmonic pulse and the e-polarization first-harmonic pulse due to group-velocity mismatch among the interacting pulses. With the proposed scheme the group velocity mismatch can be compensated. Overall energy conversion efficiency increases from 55% to 75% under the optimized conditions at the intensity of 6 GW/cm2. The temporal shape of the third-harmonic pulse with 1 ps pulse duration has no subpulses. The optimization of the efficient frequency tripling conversion for intensities of over 75 GW/cm2 is also described. The results showed that the maximum tripling energy conversion efficiency is close to 80% with the optimized doubler and tripler View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ho:Tm lasers. II. Experiments

    Publication Year: 1996 , Page(s): 104 - 111
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (832 KB)  

    For pt.I see ibid., vol.32, no.1, pp.92-103 (1996). Laser performance of Ho:Tm:YLF and Ho:Tm:YAG lasers are compared under a wide variety of experimental situations. Laser diode pumping is simulated using a Cr:BeAl2O4 laser tuned to the absorption peak of the Tm3H4 manifold for the respective laser material. Laser performance is characterized by experimentally determining the threshold and slope efficiency, and compared with predicted results of a rate equation model developed in the companion paper. Energy transfer parameters for the rate equation model are calculated using the theory developed in that paper. For these experiments, four different pump pulselengths, six different output mirror reflectivities, different Ho concentrations and different length laser materials were evaluated. Using Ho:Tm:YAG an optical slope efficiency of 0.36 was achieved while with Ho:Tm:YLF an optical slope efficiency of 0.50 was reached View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improved dispersion equation for MgO:LiNbO3 crystal in the infrared spectral range derived from sum and difference frequency mixing

    Publication Year: 1996 , Page(s): 124 - 126
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB)  

    Phase matching angles for sum and difference frequency mixing in a 7% MgO:LiNbO3 crystal of the radiation of a Ti:Sapphire laser and the radiation of 2.2 to 3.4 μm from a Raman shifter are used to determine the refractive indices of the crystal. A dispersion equation accurate in the mid-infrared spectral range as well as in the visible and near infrared range is firstly given. Based on this result the phase matching characteristic of a mid-infrared optical parametric generator using 7% MgO:LiNbO3 crystal is described View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Operation of diode laser pumped Tm3+ ZBLAN upconversion fiber laser at 482 nm

    Publication Year: 1996 , Page(s): 118 - 123
    Cited by:  Papers (18)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (672 KB)  

    Lasing at 482 nm is observed in Tm3+-doped ZBLAN glass fiber pumped with single-mode InP semiconductor diode lasers. Up to 5 mW of 482 nm light is obtained with <40 mW of absorbed pump power from a single 1135 nm pump diode laser. The optimum pump wavelength is measured to be 1135-1340 nm. More efficient laser operation is observed in fiber with 2500 ppm Tm3+ compared to 1000 ppm Tm3+ because of the reduced length of the fiber laser cavity possible with increased doping. Improved slope efficiencies are also demonstrated when the fiber laser is co-pumped with up to 5 mW from a 1220 nm diode laser. The relative intensity noise (RIN) of the fiber laser displays a maximum of -90 dB/Hz at relaxation oscillation frequencies of a few tens of kHz. The measurement of RIN is limited by shot-noise of -152 dB/Hz above 2 MHz. At higher frequencies, self mode-locking was observed in the fiber laser, which may indicate the existence of saturable absorbers in the fiber core. The presence of such bleachable absorbers is indicated by the observed increase in threshold after upconversion lasing at 482 mm 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