Design optimization of ARROW-type diode lasers

Antiresonant reflecting optical wavelength (ARROW)-type diode lasers have been optimized for high-power, single-spatial-mode operation. Calculated modal behavior predicts strong intermodal discrimination with low loss for the fundamental ARROW mode. Single-lobe far-field operation is obtained only when the high-index reflecting (antiresonant) cladding layers correspond to an optical thickness of λ₁ (m+3/4), where λ is the lateral (projected) wavelength of the leaky wave in the high-index layers, and m is an integer (m=0, 1,. . .). Experimental results include stable, single-spatial mode operation to 500-mW peak pulsed power and 300-mW CW power at an emission wavelength of 0.98 μm     

0.3 W CW single-spatial-mode operation from large-core ARROW-type diode lasers

Large-core-width (6 mu m) antiresonant reflecting optical waveguide (ARROW)-type diode lasers are demonstrated for the first time. The structures have strong intermodal discrimination with low loss for the fundamental mode. As a result, stable, single-spatial-mode operation under CW conditions is obtained up to 300 mW output power at an emission wavelength of 0.98 mu m from strained-layer InGaAs-AlGaAs devices.<>     

Complementary self-aligned laser by metalorganic chemical vapour deposition

A complementary two-step MOCVD growth technique for the self-aligned laser is described which eliminates any possible difficulty associated with regrowth on a high composition AlGaAs layer by placing the regrowth interface outside the stripe region. Single-longitudinal-mode operation with stable near and far-field patterns has been obtained to more than twice the laser threshold current.     

Phase-locked arrays of antiguides: analytical theory II

By employing a variational technique on the eigenvalue equation for finite arrays of antiguides we obtain accurate analytical expressions for key parameters characterizing the adjacent array modes: the edge radiation loss, the loss caused by interelement losses, and the effective index. The upper adjacent mode at its maximum-loss point is found to be well approximated by the sum of two Bloch waves of wavenumbers ±π/[(N-1)Λ], where N is the element number, and Λ is the array period. The intermodal discrimination, Δα, between the adjacent mode and the resonant mode (at the adjacent-mode maximum-loss point) is found to be well approximated (<10% error) by α_RR, the resonant-mode loss at resonance. Accurate analytical expressions are also derived for the two-dimensional optical-mode confinement factor Γ, and the dispersion between the resonant and adjacent modes. The obtained analytical formulas are discussed in light of device design, and general design rules are presented     

Differential gain in bulk and quantum well diode lasers

Differential gain (g^') of bulk and single-quantum-well (SQW) lasers was determined from threshold current density and differential quantum efficiency measurements. The threshold measurement technique was used to show that g^' is a function of cavity length (L) in SQW lasers and independent of L in bulk lasers. It was found that g^' of long SQW lasers (1000 μm) is about 7×10^-16 cm² , approximately two times that of bulk lasers. At short cavity lengths (250 μm), g^' is about the same for both laser types     

Room temperature photopumped ZnSe lasers

Room-temperature laser oscillation at 469 nm observed in photopumped bulk ZnSe is discussed. The result was obtained by using a pump photon energy very close to the bandgap energy and by enhancing the resonator Q with high-reflectivity coatings. Threshold pump power densities as low as 370 kW/cm² were measured     

Mode-locked multisegment resonant-optical-waveguide diode laserarrays

The first mode-locked operation of resonant optical waveguide (ROW) semiconductor laser arrays is reported. The well-behaved emission patterns of such arrays allow coupling to external cavities with efficiencies comparable to those achieved by using single-element lasers. Single- and multisegment lasers are employed to achieve active, passive, and hybrid mode-locking. The use of an arrayed gain region is effective in increasing the saturation energies of gain and absorber segments, resulting in high pulse energies. Pulses are generated that have well-suppressed secondary pulsations, with pulsewidths as short as 5.6 ps and peak powers of over 3 W in a collimated beam with a single main lobe     

A self-consistent model of a nonplanar quantum-well periodic laserarray

An analysis of a nonplanar semiconductor periodic laser array is carried out using a self-consistent model that successfully explains the experimentally observed efficiencies and output optical patterns. This model takes into account the two-dimensional injected current distribution coupled with the optical intensity profile and gain variation from the mesa to the groove. The optical field distribution of the nonplanar laser array is treated as a linear combination of the optical modes in the mesas, grooves, and bends using the effective index method. Numerical results show the multimode operation due to spatial hole burning, the near-field patterns affected by the nonuniform current injection, and the competition of available carriers among the modes of neighboring waveguides     

Photopumped antiguide blue lasers fabricated from molecular beam epitaxial ZnSe on GaAs

Room temperature photopumped laser oscillation at 469 nm has been achieved in ZnSe thin film leaky waveguide (antiguide) resonators with threshold pump intensities of about 350 kW/cm/sup 2/. The 1 mu m thick ZnSe was grown by molecular beam epitaxy on a