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We report a diode-end-pumped midinfrared multiwavelength Er:Pr:GGG laser, generating the output powers of 324 and 354 mW in CW and pulsed modes, respectively. The slope efficiencies of CW and pulsed modes are 15.18% and 16.06%, respectively. Compared with Er:GGG, the laser properties of Er:Pr:GGG are much better and the self-termination bottleneck is broken successfully. The transverse beam profile and spectra of Er:Pr:GGG laser are measured and the relationship between lasing wavelengths and operating temperature in the triwavelength emission state are also studied. The Er:Pr:GGG crystal is a potential midinfrared laser gain medium in medical and military application. [ABSTRACT FROM PUBLISHER]

High-power broad area substrate-emitting distributed feedback (DFB) quantum cascade laser emitting at λ ~ 4.6 μm is reported. Proper second-order DFB grating coupling, low waveguide loss mechanism, and epilayer-down mounting bring about a high vertical radiative optical power. The maximum peak power is as high as 1.82 W at 20 °C and still 1.22 W at 50 °C operated in pulsed mode with a pulsed width of 1 μs and duty cycle of 0.2%. A single-lobed radiation far-field with a divergence angle of 7.9 ° in the ridge-width direction and two-lobed radiation far-field with a divergence angle of 0.61 ° in the cavity-length direction are achieved by depositing the high-reflection coatings on both facets. Robust single-mode emission is continuously tunable by the heat sink temperature up to 115 °C. [ABSTRACT FROM PUBLISHER]

Buffer-free growth of GaSb on GaAs using interfacial misfit (IMF) layers may significantly improve the performance of antimonide-based emitters operating between 1.6 and 3 mum by integrating III-As and III-Sb materials. Using the IMF, we are able to demonstrate a GaSb-AlGaSb quantum-well laser grown on a GaAs substrate and emitting at 1.65 mum, the longest known operating wavelength for this type of device. The device operates in the pulsed mode at room temperature and shows 15-mW peak power at -10degC and shows high characteristic temperature (To) for an Sb-based active region. Further improvements to IMF formation can lead to high-performance lasers operating up to 3 mum. [ABSTRACT FROM PUBLISHER]

We have examined a possibility to use an AlxIn1-x P layer as an active region of a 650-nm semiconductor laser. Encouraging results have been obtained with compressively strained oxide-stripe AlInP-AlGaInP quantum-well lasers, which operated in continuous-wave mode at room temperature, producing an optical power of 460 and 320 mW per uncoated facet at 10 degC and 20 degC, respectively. In pulsed mode, a power level of 780 mW/facet was achieved at 2-A drive current at 5 degC. The results indicate that wide-bandgap AlInP affords an opportunity to develop lasers for the wavelengths 600leslambdales650 nm, which is difficult to achieve by any semiconductor heterostructure [ABSTRACT FROM PUBLISHER]

Short-wavelength (lambda<4 mum) GaInAs-AlAsSb quantum cascade (QC) lasers have been demonstrated using a "bound-to-continuum" design for the purpose of reducing the electric injection power density. As a result, we have reduced the low-temperature electric injection power density of the lasers by 40%, compared to that of GaInAs-AlAsSb QC lasers emitting at the same wavelength but adopting a triple-quantum-well design. The lasers in the present report can operate up to room temperature (300 K) in pulsed mode, emitting at short-wavelength lambda~3.7-3.9 mum [ABSTRACT FROM PUBLISHER]

Strain-compensated InGaAsSb-AlGaAsSb quantum-well (QW) lasers emitting near 2.5 μm have been grown by solid-source molecular beam epitaxy. The relatively high arsenic composition causing a tensile strain in the Al0.25GaAs0.08Sb barriers lowers the valence band edge and the hole energy level, leading to an increased hole confinement and improved laser performance. A 60% external differential efficiency in pulsed mode was achieved for 1000-μm-long lasers emitting at 2.43 μm. A characteristic temperature T0 as high as 163 K and a lasing-wavelength temperature dependence of 1.02 nm/°C were obtained at room temperature. For 2000 × 200 μm2 broad-area three-QW lasers without lateral current confinement, a low pulsed threshold of 275 A/cm2 was measured. [ABSTRACT FROM PUBLISHER]

Operation of type-II interband cascade lasers in the 4.3-4.7-μm wavelength region has been demonstrated at temperatures up to 240 K in pulsed mode. These lasers fabricated with 150-μm-wide mesa stripes operated in continuous-wave (CW) mode up to a maximum temperature of 110 K, with an output power exceeding 30 mW/f and a threshold current density of about 41 A/cm2 at 90 K. The maximum CW operation temperature of 110 K is largely limited by the high specific thermal resistance of the 150-μm-wide broad area lasers. A 20-μm-wide mesa stripe laser was able to operate in CW mode at higher temperatures up to 125 K as a result of the reduced specific thermal resistance of a smaller device. [ABSTRACT FROM PUBLISHER]

GaInAsSb-AlGaAsSb multiple quantum-well (QW) lasers with an emission wavelength of 2.81 μm are reported. The ridge waveguide lasers with highly strained QWs show continuous-wave laser emission up to 25°C; in pulsed mode, the lasers operate up to 60°C. For pulsed operation, a threshold current density of 360 A/cm2 is found for devices with 30-μm stripe width and 2-mm cavity length at room temperature. A low threshold current density at infinite length of 248 A/cm2 is derived. [ABSTRACT FROM PUBLISHER]

Self-assembled InAs quantum-dash (QD) lasers with emission wavelengths between 1.54 and 1.78 μm based on the AlGaInAs-AlInAs-InP material system were grown by gas source molecular beam epitaxy. Threshold current densities below 1 kA/cm2 were achieved for 1-mm-long mirror coated broad area lasers with a stack of four QD layers. The devices can be operated up to 80°C in pulsed mode and show a high T0 value of 84 K up to 35°C. In comparison to quantum-well lasers a much lower temperature sensitivity of the emission wavelength was achieved. The temperature shift of Δλ/ΔT = 0.12 nm/K is as low as that caused by the refractive index change [ABSTRACT FROM PUBLISHER]