Gary Lee Peterson

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. >

Two-dimensional surface-emitting leaky-wave coupled laser arrays

Leaky-wave coupling has been used for the first time to phase-lock surface-emitting antiguided arrays in a two-dimensional (2-D) configuration. Small differences between the length of separate array sections can be compensated for by phase shifts induced by carrier injection between the sections. Both four- and nine-array-section devices, arranged in diamond-shaped patterns, were phase-locked. Four-array-section devices provide far-field patterns with 35% fringe visibility to 0.2-W pulsed output power. Higher spatial coherence (45% fringe visibility) to 3.9-W pulsed output power is obtained from nine-array-section devices. The large improvement in coherent power of the nine-array-section devices appears to be because they are parallel coupled. The inherent single-spatial-mode stability of resonant optical waveguide (ROW) arrays to high drive levels above threshold allows the application of a coupled-mode formalism to 2-D arrays of ROW devices. The modeling indicates that resonant 16-array-section devices produce 10 W of spatially coherent power. >

Reflection, transmission, and scattering at an integrated diode laser-waveguide interface

A first-principle method for calculating reflection, transmission, and scattering of light at a boundary between a diode laser and an adjoining waveguide is presented. The electric field on each side of the boundary is expanded in terms of the trapped modes and radiation modes of the laser and waveguide. A matrix equation for the coefficients of each mode is then obtained by matching the fields and their longitudinal derivatives at the boundary. This equation is solved numerically to obtain a reflection and scattering matrix for the fraction of the incident light reflected into each trapped mode of the diode laser, scattered into radiation modes, and transmitted into an adjoining waveguide. Results obtained from this method are compared with calculations using the effective index of refraction technique and an overlap integral analysis to determine when these simpler approaches are valid.

High-power coherent diode lasers

Diffraction-limited beam operation at high output power levels (0.5 W cw and 1.5 W pulsed) has been demonstrated from resonant-optical-waveguide (ROW) array structures. Uniphase mode operation is achieved without the need for active phase control. As a result, a reliable monolithic device capable of watt-range coherent output power is obtained.

0.36-W cw diffraction-limited-beam operation from phase-locked arrays of antiguides

Diffraction-limited beam operation at high output power levels (0.36 W cw and 1.5 W pulsed) have been demonstrated from resonant-optical-waveguide array structures. Uniphase mode operation is achieved without the need for active phase control. As a result, a reliable monolithic device capable of watt-range coherent output power is obtained.

Stabilized in-phase-mode operation from monolithic antiguided diode laser arrays

Stabilized in-phase mode oscillation is demonstrated from large-aperture 20-element antiguided diode laser arrays. 20-element resonant optical waveguide arrays emit 160 mW total power at 2.8 x I(th) in a diffraction-limited beam and have high spatial coherence across the entire array. CW operation of nonresonant 20-element array structures is demonstrated to high output power levels.