Phase-locked Arrays Of Antiguides Research Articles

10 W near-diffraction-limited peak pulsed powerfrom Al-free,0.98 µm-emitting phase-locked antiguided arrays

10 W peak-pulsed power emitted in a beam pattern 2×diffraction limit (DL) is obtained from a 40-element, 200 µm-aperture Al-free phase-locked antiguided array (λ = 0.98 µm). 60% of the power resides in the central lobe, and the external differential quantum efficiency is 54% for 1 mm-long optimised facet-coated devices.

Distributed-feedback grating used as a lateral-mode selector in phase-locked antiguided arrays

We show here, for the first time, that a distributed-feedback (DFB) grating can act as a lateral-mode discriminator if located below the active region of a phase-locked antiguided array. Spatial-mode selection from such a lower-DFB (LDFB) grating in a resonant antiguided structure (ROW-LDFB) relies on the fact that the optical field distribution below the active region is strongly array-mode dependent. In particular, it is shown that at and near resonance a ROW-LDFB structure strongly favors resonant-mode oscillation, while suppressing oscillation of high-order modes. ROW-LDFB devices thus accomplish both spatial- and frequency-mode selection in a single structure. Furthermore, for effective intermodal discrimination, there is no need for interelement loss or Talbot-type filters, thus eliminating all potential sources of self-pulsations.

Corrections to "Phase-Locked Arrays of Antiguides: Analytical Theory"

Corrections to "Phase-Locked Arrays of Antiguides: Analytical Theory"

Optical properties of dual-state Fabry–Perot étalons

We consider the optical properties of dual-state Fabry-Perot étalons where both the cavity and the external media can support two eigenmodes with different refractive indices. A matrix formulation is developed to analyze resonant transmission of such étalons. The results are presented and discussed. In particular, the results can be employed to explain the resonances of phase-locked arrays of antiguides.

Phase-locked arrays of antiguides: model content and discrimination

Three classes of array modes of closely spaced antiguides are analyzed: coupled fundamental (element) modes, coupled first-order (element) modes, and modes adjacent to coupled fundamental modes. The behavior of coupled fundamental modes as a function of lateral index step is analyzed and explained from a ray-optics point of view. It is found that at resonance, for both coupled fundamental and first-order modes, the array-mode propagation constant is virtually identical to the propagation constant of the mode of a single, unperturbed antiguide. Several types of mode discrimination mechanisms are discussed. For devices with 3- mu m-wide antiguide cores and 1- mu m interelement spacing, intermodal discrimination values of 15-20 cm/sup -1/ can be achieved. Excellent agreement is found between experimental data and theoretical predictions based on the effective-index method. >

High-power, narrow single-lobe operation from 20-element phase-locked arrays of antiguides

Pure in-phase-mode operation is obtained from 20/21-element AlGaAs/GaAs antiguided arrays grown by two-step metalorganic chemical vapor deposition. Oscillation of out-of-phase modes is substantially suppressed by a built-in spatial filter: two sets of noncollinear antiguides separated by a 50-μm-long laterally unguided region, corresponding to the half-Talbot distance. Design considerations for 20- vs 10-element arrays are discussed. Diffraction-limited-beam operation (i.e., 0.8° lobewidth) is obtained to 1.5×threshold (90 mW, both facets). Beams with 1.3° lobewidth (1.6×diffraction limit) are obtained at 3×threshold and 300 mW (both facets). Devices with optimized facet coatings operate in a single, 1.5°-wide lobe (i.e., 1.8×diffraction limit) at 330 mW front-facet emitted power. The main lobe contains 80–87% of the total power.