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Midinfrared “W” quantum-well diode lasers with reduced turn-on voltages are reported. Devices with coated facets operated in continuous-wave mode up to 195 K, where the emission wavelength was 3.56 μm. At 78 K, the threshold current density was 67 A/cm[sup 2], the maximum output power was 198 mW, and the slope efficiency was 106 mW/A. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We investigate broad-stripe photonic-crystal distributed-feedback lasers emitting at λ=4.4 μm. The beam quality improves dramatically when a laser ablation technique is used to eliminate parasitic Fabry–Pérot-like modes, by inducing loss in the regions adjoining the pump stripe. Even though the peak of the gain spectrum never fully aligns with the grating resonance, for pulsed pumping the output beam is essentially diffraction limited up to a stripe width of 150 μm, and remains no worse than six times the diffraction limit for stripes as broad as 400 μm. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Whereas laser emission at 1.55 μm is difficult to realize using type-I InGaAsN quantum wells grown on GaAs, we show that it can be achieved with far fewer restrictions on the growth by employing type-II (In)GaAsN/GaAsSb/(In)GaAsN/GaAs structures having a “W” band alignment. We use a 10-band k·p formalism that accounts for the N band anticrossing to calculate the gain and spontaneous-emission characteristics of “W” structures optimized for maximum overlap of the electron and hole wave functions. We estimate that one to three wells would be necessary for edge emitters with moderate cavity losses and nonradiative recombination rates, and a somewhat larger number of wells may be required for vertical-cavity surface emitters. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

It is shown theoretically that semiconductor optical amplifiers (SOAs) with type-II quantum-well active regions in SOAs will have up to 10 dB lower interchannel crosstalk at high (>2.5 Gb/s) data rates. That reduction is attained via the corresponding increase in saturation energy without any reduction in the efficiency [ABSTRACT FROM PUBLISHER]

Optically pumped type-II QW lasers emitting in the 5.4-7.1 -μm wavelength range and at continuous-wave (CW) temperatures up to 210 K are demonstrated. At 80 K, the maximum CW output power from a 40-μm-wide pump stripe is 48 mW at 5.41 μm and 31 mW at 6.05 μm. Epitaxial-side-down heat sinking is provided by a new diamond-pressure-bond mounting technique, which requires minimal processing and maintains topside optical access [ABSTRACT FROM PUBLISHER]

Focuses on superlattice diodes' display of strong negative luminescence under reverse bias. Measurement of the negative emittance at room temperature; Main features of the data reproduced by photodiode simulation.

Reports that optically pumped type-II W lasers emitting in the mid-infrared exhibited continuous-wave (cw) operating temperatures of 290 K at lambda=3.0 mu m and 210 K at lambda=6.1 mu m. Maximum cw output powers for 78 K.

Examines issues related to pulsed-power determinations for midinfrared semiconductor lasers. Recalibration of previous pulsed midinfrared semiconductor laser characterization; Measurements of a detector's peak response versus pulse width; Fourier transform magnotude of the impulse response of various detector configurations.

Describes an optical pumping injection cavity (OPIC] edge-emitting laser which employs GaSb/AlAsSb distributed Bragg reflectors above and below the type II W active region. Incident threshold pump intensity; Incident power conversion efficiencies per facet of nine percent; Experimental and simulated transmittance of the W-OPIC structure at normal incidence.

Examines the photoelectric properties of mercury telluride-cadmium telluride superlattices. Reduction of the tunneling noise and minority carrier collection efficiency; Effects of valence-band offset on electron and hole masses; Application of superlattices to long wavelength infrared detectors.

Investigates indium arsenide and gallium indium antimonide superlattices. Utilization of magneto-optical and magnetotransport techniques in the analysis; Determination of band gaps; Measurement of both electron and hole effective mass.

Examines the setback modulation of doping of mercury telluride-cadmium telluride heterostructures using photoassisted molecular beam epitaxy. Influence of setback on electron mobility; Enhancement of the electron mobility; Combination of the quantum Hall effect measurements with the mixed conduction analysis.

Examines nondegenerate four-wave mixing measurements on a molecular beam epitaxy-grown Bi[sub 1-x]Sb[sub x] film. Role of the etalon effect in enhancing the four-wave signal; Importance of nonlinearity as a function of temperature; Link between linear reflectivity spectra and four-wave mixing.

Reports that interface roughness is the dominant low-temperature scattering mechanism for electrons in superlattices with thin wells. Reproduction of the observed temperature; Generalization of the treatment of interface roughness scattering for narrow-gap superlattices.

Examines the type II mid-infrared quantum well lasers. Illustration of the threshold behavior at a series of elevated temperatures; Result of the shifting of energy gap resonance; Realization of the full potential for Auger suppression.

Investigates the Auger lifetimes for InAs, InAsSb, IAsSb-InAlAsSb quantum wells. Correlation of the Auger rate at 77 Kelvin with the proximity to resonance between the energy gap and the split-off gap; Reduction of the Auger coefficient in the alloy with decreasing temperature; Rise of the Auger coefficient of the quantum well with decreasing temperature.

Examines the electro-optical modulators based on intersubband transitions induced by normal incidence radiation in GaSb-AlSb-family asymmetric double quantum wells. Discussion on the electro-optical modulator; Effectiveness of the applied field; Alteration of the selection rules, resonance energies, and in plane effective masses.

Examines the application of type-II quantum well lasers to mid-wavelength infrared. Comparison between quantum well and double heterostructure lasers; Details on the energy levels and wavefunctions quantum wells; Suppression of the Auger recombination rate.

Proposes an intersubband-based frequency-mixing device with voltage-controlled imposition of phase matching. Production of strong linear absorption through optical nonlinearity and intersubband transitions; Variety of the phase matching techniques used; Use of an external field for refractive index tuning.

Investigates the Auger recombination lifetime in InAs-Ga[sub 1-x]In[sub x]Sb superlattices. Analysis of data on photoconductive response to frequency-doubled CO[sub 2] radiation; Calculation of the superlattice band structure; Observation of Auger lifetimes of two orders of magnitude.

Examines the monolayer thickness fluctuations in infrared photoluminescence for [211]-oriented HgTe-CdTe superlattices. High growth quality indications of double and triple peaks; Use of a band-to-band model; Calculation of energy gaps using an eight-band transfer-matrix algorithm.

Examines the interface roughness scattering in semiconducting InAs-Ga[sub 1-x]In[sub x]Sb superlattices. Growth of the superlattices on gallium arsenide substrate; Observation of semimetallic band alignment in the superlattices; Coexistence of two electron species in semimetallic superlattices.

Describes the epitaxial growth of antimony (Sb) films on gallium antimonide (GaAs) substrates. Influence of a confinement-induced positive energy gap on nonlinear optical switches; Exploitation of the long mean free path in Sb for quantum transport evaluation; Application of Sb/GaAs system to electronic devices incorporating heterostructures.

Describes the fabrication of nanometer scale features in the narrow gap, compound semiconductor mercury cadmium telluride. Application of electron-beam lithography and reactive ion etching; Effect of methane concentration and substrate bias on etch rate; Use of scanning electron microscopy.