IEEE Journal of Quantum Electronics

In this paper, we present a simulation model to optimize and engineer EuSe-PbSe0.78Te0.22-EuSe single-quantum-well lasers. We solve for the effects of strong nonparabolicity of the bands on the optimization process. The optical energy confined in the active region is also calculated for multiple-quantum-well (MQW) lasers. The modal gain-current density relation for this struc... View full abstract»

An adaptive optical sequence generation scheme has been described in a nonlinear optical ring which exhibits chaotic dynamics. The adaptation is based on avoidance of collisions between the ring output and signals from another source. It is shown that collision-avoiding sequences can be autonomously selected via chaotic mode transitions induced by the feedback of collision signals. Experimental re... View full abstract»

The optical properties of quantum wells on GaxIn1-xAs1-yPy are investigated. The dielectric function ε(ω) is calculated with a density matrix formalism valid for excitonic transitions as well as for the interband absorption including band mixing. With two simple approximations, the required number of overlap integrals is greatly reduced, allow... View full abstract»

Spectral broadening due to fiber amplifier phase noise has been investigated experimentally. Results differ from previously published data. The measured spectral broadening reveal to be much smaller than expected View full abstract»

Structural, electrical, and ultrafast optical properties of furnace-annealed arsenic-ion-implanted GaAs (GaAs:As+) has been investigated for its applications in ultrafast optoelectronics. From these studies, we determine that GaAs substrates implanted with 200-keV arsenic ions at 1010 ions/cm2 and furnace-annealed at 500°C-600°C would have recovered its cry... View full abstract»

Narrow linewidth and stabilized light injection is employed to reduce the phase noise and stabilize the frequencies of individual teeth of an active mode-locked laser diode (ML-LD) which is modulated by both fundamental and subharmonic frequencies of the cavity free-spectral range (FSR). We demonstrate accurate frequency control of the ML-LD using an injection seed light with linewidth of less tha... View full abstract»

We theoretically analyze 630-nm band GaInP-AlGaInP tensile-strained quantum-well (QW) lasers with doping in the active region. The radiative current can be significantly reduced by introducing n-type doping in the active region. However, this advantage is reduced by the increase of the leakage current. As a result, the threshold current is reduced and the emission wavelength is shortened for multi... View full abstract»

A comprehensive physics-based three-dimensional (3-D) model for distributed feedback (DFB) lasers is developed and presented. The model considers self-consistently optical confinement, carrier transport and heat transfer over the two-dimensional (2-D) cross section. It also accounts for the longitudinal spatial hole-burning effect along the laser cavity. A rigorous optical gain model is incorporat... View full abstract»

A newly designed high-repetition rate regenerative amplifier system producing sub-50 fs, ~7 μJ pulses at 100 kHz (~4 μJ at 250 kHz) is used to pump a fully tunable optical parametric amplifier (OPA). The resulting transform limited visible pulses in the 510-610-nm range have pulsewidths of ~40 fs and energies in the range of 350-550 nJ. Doubling these pulses in thin (0.110-0.150 mm) BBO crys... View full abstract»

We explore the analytical dependence of the free-electron laser (FEL) saturated power on the cavity detuning and discuss the dependence of the higher harmonics generated power on this quantity. We show that a suitable modulation of the cavity detuning may provide a pulsed behaviour of the laser, superimposed to the natural mode locking. The new temporal characteristics of the laser are discussed a... View full abstract»

We present a tight-binding analysis of the polarization dependence of GaAs δ-strained semiconductors optical amplifiers. Our approach allows us to account for band nonparabolicity, valence band mixing, as well as thin layer perturbations, overcoming the natural limitations of standard techniques based on the envelope function formalism. We explain how thin strained GaAs layers embedded in a ... View full abstract»

The results from experiments relating to the CW operation of a Tm-Ho-doped silica fiber laser which is pumped with the fundamental output from a Nd:YAG laser are presented. The measured maximum output power from the fiber laser of 11 mW was generated at a slope efficiency of approximately 1.8% for a fiber length of 0.574 m and an output coupling of 10%. An output wavelength of 2170 nm (one of the ... View full abstract»

Widely tunable lasers are essential components for high-capacity wavelength-division-multiplexed (WDM) transmission and photonic switching systems. For these optical fiber communication systems, they offer several advantages to increase the capacity, the functionality, and the flexibility of WDM networks. Nevertheless, these widely tunable transmitters must satisfy several stringent requirements d... View full abstract»

In this paper we use an exact calculation of dipole emission modifications in an arbitrary multilayer structure to obtain the extraction efficiency from realistic planar microcavities, additional insights gained through this exact approach compared to the simplified one of Part I of this paper [see ibid., p. 1612, 1998] are first discussed in the case of a dielectric slab. We next optimize for the... View full abstract»

A novel frequency-domain transmission line model for multisection distributed feedback (DFB) lasers is developed. The characteristic impedances of active periodic structures are derived. A multisection DFB laser is described as a transmission line network, with each section represented by a transmission lint segment with a corresponding characteristic impedance. Static, dynamic, and noise analysis... View full abstract»

The exchange of power between two identical coupled waveguides with embedded periodic structure along the direction is studied in the framework of Floquet-Bloch theory. A one-period propagator is calculated and a spectrum of its eigenvalues (eigenphases) is studied. We show that due to special symmetry properties of the Floquet-Bloch operator, a strong enhancement or a total suppression of power e... View full abstract»

Experimental evidence that in quantum cascade lasers electron injection into the active region is controlled by resonant tunneling between two-dimensional subbands is discussed. A quantitative analysis is carried out using an equation for the current density based on a tight-binding approximation. Electron injection into the active region is optimized when the current density is limited by the lif... View full abstract»

Strongly pumped fiber lasers are analyzed, based on a rate equation model. Examples include Nd3+-doped and Yb3+ -doped fiber lasers, with distributed Bragg reflector mirrors at either end. Approximate analytical and quasi-analytical expressions are shown to be in excellent agreement with the exact numerical solution of the rate equations, and both agree well with recently pub... View full abstract»

The performance of a master-slave configuration for effecting the synchronization of chaotic vertical-cavity surface-emitting lasers (VCSELs) is studied using numerical simulations. The dynamical evolution of optically coupled VCSELs is examined using a traveling wave model which is valid in the strong optical feedback regime. It is shown that the proposed configuration is capable of effecting syn... View full abstract»

A key issue in widely tumble laser diodes employing codirectional mode coupling is the number of accessible wavelength channels. Depending on the device structure, only a fraction of about 25% of the available cavity modes can typically be accessed. In this paper, we identify the suppression of individual longitudinal modes by internal reflections at the grating and other waveguide inhomogeneities... View full abstract»

We address the long-standing issue of extracting light as efficiently as possible from a high-index material, n⩾2, where as little as 2%-10% of light not suffering total internal reflection is extracted at standard plane faces due to the small critical angle ~1/n. Using a planar microcavity to redirect spontaneous emission toward the surface, constructive interferences can bring 15%-50% of the... View full abstract»

Laser power stabilization for a chemical oxygen-iodine laser (COIL) was demonstrated using a complete feedback system with an external magnetic field based on the Zeeman effect of the iodine transition. The input/output characteristics of the feedback system are theoretically analyzed and found to be consistent with the experimental results. As a result, highly stable output power of less than 0.4... View full abstract»

A comprehensive model for steady-state analysis of polarization-mode competition in fiber distributed feedback (DFB) lasers is presented. Effects of polarization-dependent grating nonuniformities, polarization-dependent grating strength, coupling between the linear polarization states due to twist or Faraday rotation, back reflections, cross saturation from serially multiplexed lasers, as well as ... View full abstract»

We consider the interpulse dynamics in harmonic passively mode-locked soliton lasers and find that gain depletion in conjunction with its recovery provides an effective repulsion force between adjacent solitons by imparting a group-velocity drift proportional to the interpulse spacings. Analytic descriptions for both the two-pulse and N-pulse per round-trip configurations demonstrate the stability... View full abstract»

In this paper we describe the properties of GaxIn1-xP-(AlyGa1-y) 0.52In0.48P strained quantum-well (QW) lasers at compressive strains of greater than 1%. Structures containing single 100-Å GaxIn1-xP QW's of different compositions have been grown by low-pressure metal organic chemical vapor deposition (MOC... View full abstract»