Nonlinear gain suppression in semiconductor lasers due to carrier heating (original) (raw)

Carrier heating effects in dynamic-single-frequency GaInAsP-InP laser diodes

IEEE Journal of Quantum Electronics, 1995

The fully self-contained model of a laser diode (LD) under the carrier heating conditions based on the description of a nonequilibrium carrier-phonon-photon system excited by an injection in a P-1-N double heterostructure @I%) is presented. It combines the microscopic approach to the lightcarrier interaction with the macroscopic treatment of the device characteristics and does not for example involve any empirical formulation of nonlinear gain. This model is used to investigate the carrier heating effects in the CW operation, small-signal modulation response and nonlinear picosecond (ps) dynamics of a single-frequency GaInAsP-InP laser. The carrier heating induced suppression of the material gain and enhancement of the intracavity losses are shown to be important for all operational modes. In the CW performance, these effects are found to cause the saturation of lasing and blue shift of the generation wavelength. In the high-frequency response, they are established to ensure an additional mechanism of dynamical carrier-photon coupling and therefore m d i y the modulation behavior of an LD. For nonlinear dynamics, the carrier heating induced perturbation of the gain and losses are shown to lead to deep pulse modulation on a ps timescale. AU the numerical estimations and modeling examples are given for 1.55 pm distributed feedback (DFB) laser operating at mom temperature. It is concluded that carrier heating effects are unwelcome phenomena for CW operation, but they can be engaged to improve the modulation behavior of an LD. AL bandgap narrowing [8]-[lo], and so the carrier heating effects have to be especially significant in the long-wavelength GaInAsP-InP lasers. Carrier heating influence on lasing is frequently described in terms of nonlinear gain [11]-[13], when the mode gain coefficient at a frequency w is written as T~ = Tw,$h(Ne)(l-awNw) [111, [I21 or ^lw = Tu,th(Ne)/(l-k CwNw) [I319 Manuscript

Nonlinear gain model and its application for numerical investigation of semiconductor lasers

1999

The optimization of parameters and adequate methods of modeling for the creation of new types of semiconductor lasers with impro¨ed properties are required. In this work, a numerical model of gain is presented, which contains a complex description of the linear and nonlinear effects in an acti¨e layer. We show the more exact conformity of the gi¨en model to experimental data for large le¨els of light power and pumping currents. The original method of calculations of the total ( ) density states function for the quantum well QW laser is shown. The gi¨en expression has allowed us to reduce the model calculation time.

On the temperature sensitivity of semiconductor lasers

Applied Physics Letters, 1992

The temperature dependence of below-threshold emission from multiple quantum well semiconductor lasers is well characterized by a power law, in excellent agreement with Landau-Ginzburg theory of second-order phase transitions. We thereby show that it is the temperature dependence of net gain and not that of nonradiative recombination which primarily determines temperature sensitivity of threshold in long-wavelength injection lasers.

A theoretical investigation of the characteristic temperature T0 for semiconductor lasers

IEEE Journal of Selected Topics in Quantum Electronics, 2003

The temperature dependence of the characteristic temperature T 0 of semiconductor quantum-well lasers is investigated using detailed simulations. The critical-temperature-dependent processes are the optical gain and the nonradiative recombination. The gain model is based on k p theory with the multiple quantum wells in the active layer represented by a superlattice. The Auger process is assumed to be thermally activated. It is shown that, with inclusion of the continuum state filling and interband mixing, the most important features experimentally observed in the temperature dependence of the T 0 value can be explained. The continuum state filling and band nonparabolicity cause a significant deviation from the ideal linear carrier density versus temperature relation for quantum wells. The results are compared to experiment for broad area devices lasing at 980 nm and 1.3, and 1.55 m, and show good agreement over a broad range of temperature.

Temperature dependence of long wavelength semiconductor lasers

Applied Physics Letters, 1992

We compare the temperature dependent characteristics of multiple quantum well semiconductor laser diodes and light emitting diodes operating at a wavelength, /z = 1. 3 ,um. No model in which Auger recombination is the dominant temperature sensitive parameter can explain our experimental observations. We suggest that net gain is the appropriate temperature dependent variable which determines laser diode performance at elevated temperatures.

Side-mode gain in semiconductor lasers

Journal of the Optical Society of America B, 1992

Side-mode gain and coupling coefficients in semiconductor laser media are calculated with the use of a multimode Fourier technique valid both for mode spacings that are small compared with the carrier-carrier relaxation rates and for spacings comparable with these rates as predicted by the Boltzmann theory of Binder et al. [Phys. Rev. B 45, 1107]. The medium is described by a free-carrier model that provides for carrierprobability pulsations around quasi-equilibrium Fermi-Dirac values. We find that population pulsations play just as important a role as spectral hole burning for mode spacings comparable with the intraband relaxation rates. For the carrier-carrier relaxation rates of Binder et al., side-mode gain is predicted to be smaller than the main-mode gain, leading to single-mode operation. However, for somewhat smaller intraband relaxation rates, side-mode gain is readily found that exceeds the single-mode gain, which would encourage multimode operation. In addition, we find that the gain and coupling coefficient spectra are sensitive to the k dependence of the carrier-carrier relaxation rates and might provide a useful way to measure these rates. We are also able to explain the asymmetric side-mode gain spectra for small beat frequencies in terms of the rapid decrease of the quasi-equilibrium Fermi-Dirac electron distribution just above the gain region.

Gain saturation in semiconductor lasers: Theory and experiment

IEEE Journal of Quantum Electronics, 1982

The semiconductor stimulated gain saturation model of Zee has been extended using reasonable approximations to obtain an anaiytical solution for the gain saturation process in PbSnTe and to determine the limit to single mode power directly from the gain expression, the intraband relaxation time, and device and material parameters.

Reduction of damping in high-speed semiconductor lasers

IEEE Photonics Technology Letters, 2000

We derive an analytical expression for the intrinsic gain suppression factor based on carrier heating. The theory shows good agreement with the published experimental value of E = + 1.5 X 10 -I 7 cm3 for in-plane lasers. For the first time, we