Ultrahigh Aggregate Bandwidth Two-Direnrional Mulltiple-Wavele th Diode Laser Arrays N00014-93-1-0558

Approved for public release; distribution unlimited 13. ABSTPACT (Msmmaa 00wct iw Two-dimensional (2D) multi-wavelength vertical cavity surface emitting laser (VCSEL) arrays is promising for ultrahigh aggregate capacity optical networks. A 2D VCSEL array emitting 140 distinct wavelengths was reported by implementing a spatially graded layer in the VCSEL structure, which in turn creates a wavelength spread. In this program, we concentrated on novel epitaxial growth techniques to make reproducible and repeatable multi-wavelength VCSEL arrays. Our approach to fabricate the spatially graded layer involves creating a nonuniform substrate surface temperature across the wafer during the growth of the cavity spacer region using the fact that the molecular beam epitaxy growth of GaAs is highly sensitive to the substrate temperature. We are investigating growth with the use a patterned spacer (either a Ga or Si substrate) placed in-between the substrate and its heater. We have calculated the temperature distributio