By Topic

Quantum Electronics, IEEE Journal of

Issue 1 • Date Jan 1997

Filter Results

Displaying Results 1 - 15 of 15
  • Aging time dependence of catastrophic optical damage (COD) failure of a 0.98-μm GaInAs-GaInP strained quantum-well laser

    Page(s): 66 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (984 KB)  

    In this paper, we studied the aging time dependence of the catastrophic optical damage (COD) failure of an Al-free uncoated 0.98-μm GaInAs-GaInP strained quantum-well laser with an injection current as a parameter. Based on the stress-strength model, we first investigated experimentally the dependence of the critical power level (CPL) at which COD would take place upon the aging time. Then applying a statistical treatment to this result, we found for the first time that CPL data at each aging time could be considered to distribute according to the Weibull statistics, and the decrease rate of the CPL with the aging time depended very strongly on the injection current. Finally, using the relationship between the decrease rate of the CPL with the aging time and the current, we predicted roughly the time of a COD failure occurrence for both large and small current cases. As a result, we clarified that for our Al-free uncoated 0.98-μm laser, a COD failure became a fatal problem in the case of a large-current (high-power) operation View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spectral characteristics of an all solid-state frequency-shifted feedback laser

    Page(s): 103 - 111
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1012 KB)  

    A laser cavity closed via the first-order diffracted light of an acoustooptic modulator is referred to as a frequency-shifted feedback laser (FSF laser). This laser exhibits outstanding features in its oscillation spectrum. We previously demonstrated the first oscillation of an all solid-state FSF laser, and it turned out experimentally that the oscillation spectrum consists of a continuously chirped comb of frequency components. Furthermore, we have been investigating oscillation dynamics both experimentally and analytically for a better understanding of FSF laser. Here experimental results and analyses on the spectral characteristics of the laser are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Double-tapered-waveguide distributed feedback lasers for high-power single-mode operation

    Page(s): 71 - 80
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1348 KB)  

    Theoretical analysis of double-tapered-waveguide distributed feedback semiconductor laser for stable single-mode and high-power operation is presented. It is found that the single-mode behavior of a distributed feedback laser with large coupling-length product can be improved significantly by the double-tapered-waveguide structure View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Noise analysis of frequency converters utilizing semiconductor-laser amplifiers

    Page(s): 81 - 88
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1128 KB)  

    This paper deals with a general problem concerning semiconductor-laser amplifiers used for frequency conversion. The amplified spontaneous emission (ASE) of a saturated amplifier is investigated experimentally and theoretically. An analytical solution accounting for the spatial dependence of the inversion parameter as well as the spectral dependence of the ASE is derived. Hence, the results can be applied to arbitrary saturation conditions and frequency shifts. Our theory is applied to frequency converters based on four-wave mixing and is found to be in good agreement with both the numerical results and the experimental data. In order to quantify the performance of a frequency converter, a noise figure is defined and shown to be strongly dependent on the frequency detuning and the power of the input waves View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characterization and modeling of a noncollinearly phase-matched femtosecond optical parametric oscillator based on KTA and operating to beyond 4 μm

    Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1060 KB)  

    We describe the design and operation of a critically phase-matched femtosecond optical parametric oscillator based on KTA. By employing a small pump-signal noncollinear angle, tuning of the idler to beyond 4 μm is achieved using a Ti:sapphire pump laser. A Gaussian-beam model is described which can be used to identify the optimal noncollinear phase-matching geometry. Idler and signal pulses are characterized fully both temporally and spectrally and interferometric autocorrelation data at 3.5 μm showing idler pulses of only eight optical cycles duration are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pulsed and continuous-wave operation of long wavelength infrared (λ=9.3 μm) quantum cascade lasers

    Page(s): 89 - 93
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (660 KB)  

    The operation of quantum cascade lasers at a wavelength (λ≃9.3 μm) well within the 8-13-μm atmospheric window is reported. A detailed study of intersubband luminescence in a vertical transition structure shows linewidths as narrow as ~10 meV at cryogenic temperatures, increasing to 20 meV at room temperature. Pulsed operation is demonstrated up to 220 K with a peak power ≈10 mW and ≈35 mW at 140 K. The temperature dependence of the threshold current density (J th) is described by a high T0 (128 K), Jth is also systematically studied as a function of cavity length to determine the peak gain and waveguide losses. Continuous-wave, single-mode operation is demonstrated up to 30 K with powers ≈2 mW View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Monolithic integration in InGaAs-InGaAsP multiple-quantum-well structures using laser intermixing

    Page(s): 45 - 55
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1684 KB)  

    The bandgap of InGaAs-InGaAsP multiple-quantum-well (MQW) material can be accurately tuned by photoabsorption-induced disordering (PAID), using a Nd:YAG laser, to allow lasers, modulators, and passive waveguides to be fabricated from a standard MQW structure. The process relies on optical absorption in the active region of the MQW to produce sufficient heat to cause interdiffusion between the wells and barriers. Bandgap shifts larger than 100 meV are obtainable using laser power densities of around 5 W·mm-2 and periods of illumination of a few minutes to tens of minutes. This process provides an effective way of altering the emission wavelengths of lasers fabricated from a single epitaxial wafer. Blue shifts of up to 160 nm in the lasing spectra of both broad-area and ridge waveguide lasers are reported. The bandgap-tuned lasers are assessed in terms of threshold current density, internal quantum efficiency, and internal losses. The ON/OFF ratios of bandgap-tuned electroabsorption modulators were tested over a range of wavelengths, with modulation depths of 20 dB obtained from material which has been bandgap-shifted by 120 nm, while samples shifted by 80 nm gave modulation depths as high as 27 dB. Single-mode waveguide losses are as low as 5 dB·cm-1 at 1550 mm. Selective-area disordering has been used in the fabrication of extended cavity lasers. The retention of good electrical and optical properties in intermixed material demonstrates that PAID is a promising technique for the integration of devices to produce photonic integrated circuits. A quantum-well intermixing technique using a pulsed laser is also demonstrated View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Chaotic effects in flared lasers: a numerical analysis

    Page(s): 26 - 32
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1052 KB)  

    A numerical analysis of chaotic effects in flared laser structures is presented. A numerical model based on the beam propagation method is used which includes saturation and temperature effects. Instabilities observed at the output are shown to be chaotic. Reconstruction of the strange attractor is employed for analysis of the leading Lyapunov exponent and the correlation dimension. Different control parameters are examined, and all show several phases of the system: stable, periodic, and chaotic View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal design of optically side-pumped lasers

    Page(s): 94 - 102
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1228 KB)  

    A ray-tracing algorithm is used to determine the pump-absorption distribution, and the mode-coupling efficiencies to specific transverse modes are calculated. We develop a model for optimizing the pumping geometry for an optical side-pumped laser medium. Analytic and numerical results are given for the case of TEM00 laser output arising from a few examples of Gaussian pumping. We also model the performance of a close-coupled, side-pumped configuration that is found in numerous recent high-power laser-diode-pumped solid-state lasers. A particular advantage of this system approach is that it allows characterization and selection of pump configurations before fabrication of the pump cavity View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A generalized model for passively Q-switched lasers including excited state absorption in the saturable absorber

    Page(s): 41 - 44
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (532 KB)  

    A generalized model of a passively Q-switched laser is presented. It enables performance optimization including cases in which the saturable absorber exhibits both ground and excited state absorption (ESA) at the laser wavelength. The model accounts for the properties of the lasing material, the saturable absorber, and the resonator. The procedure for using this model to determine resonator and Q-switch parameters which optimize the laser's performance is described and the model is applied to reported systems to demonstrate its use View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radial birefringence in optical resonators

    Page(s): 18 - 25
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB)  

    Paraxial fields polarized in the transverse plane and represented in the polar coordinate system are expanded in an azimuthal Fourier series. For series terms with spiraling phases, the radial and azimuthal components are shown to mix during propagation. For simple rod lasers with thermally induced birefringence, this property may cause the dominant mode to be of mixed polarization rather than purely radial polarization. An explanation is given in terms of the properties of scalar field propagators and the way in which they combine to propagate the vector field components. Comparisons to other recent predictions show that the theory is correct, and the method provides a basis for understanding the complex results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Chaos control and noise suppression in external-cavity semiconductor lasers

    Page(s): 56 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1564 KB)  

    Feedback-induced chaos and intensity noise enhancement in a laser diode with external optical feedback are studied by computer simulations. The enhancement of relative intensity noise (RIN) that is often observed in experiments is considered as a result of the feedback-induced deterministic chaos and the intensity noise suppression is treated from the viewpoint of chaos control. Especially, the conventional noise suppressing technique known as a high-frequency injection modulation is turned into a problem of stabilizing chaos through parameter modulations. We developed an analytical method which allows to optimize the modulation frequency from the linear stability analysis of the dynamical model that describes the laser diode with external feedback. The robustness of the modulation with respect to the modulation frequency and depth is verified and the results suggest the feasibility of applying our method to actual noise suppression. The RIN in the low-frequency region (up to 100 MHz) is shown to be reduced to the solitary laser level when the feedback-induced chaos is effectively controlled with the optimized modulation frequency View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Generation of frequency-chirped optical pulses in a large-slippage free-electron laser

    Page(s): 10 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (892 KB)  

    We have investigated the optical output of the free-electron laser for infrared experiments (FELIX) when it is driven by an electron beam with a ramped energy. We show that the applied slow ramp on the electron beam energy leads to a frequency chirp on each picosecond optical pulse. Typical values for the chirp are 0.2% frequency sweep across a 1.5-ps-long optical pulse. The optical pulses were analyzed with a double-grating pair and with a second-order autocorrelator. The pulse duration was reduced in the double-grating pair by 20%. A linear dependence of the chirp on the cavity desynchronization was measured View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improvement of single-mode gain margin in gain-coupled DFB lasers

    Page(s): 33 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1108 KB)  

    Using the Bloch-wave analysis, this paper investigates the effect of the gain grating on the single-mode condition in DFB lasers. Various factors affecting the threshold gain of gain-coupled DFB lasers are analyzed in some detail. It is shown for the first time that unequal section lengths in the gain grating can have a significant effect on the single-mode gain margin of gain-coupled DFB lasers, especially when the linewidth enhancement factor αM is large, because the long and shortwavelength Bloch waves are in phase and in antiphase with the index grating of DFB lasers, respectively View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Diode-pumped Ho:Tm:LuLiF4 laser at room temperature

    Page(s): 112 - 115
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (460 KB)  

    A diode-pumped room-temperature Ho:Tm:LuLiF4 laser achieved an optical efficiency of 9.4% under normal mode operation. Under similar experimental conditions. Ho:Tm:LuLiF4 yielded 1.5 times greater optical efficiency than Ho:Tm:YLiF4. Absorption spectra and lifetimes as a function of pump energy were measured for evaluation of this laser material 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