Ultra-high aggregate bandwidth two-dimensional multiple-wavelength diode laser arrays
Abstract
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. Concentrtion was on 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. Growth is investigated with the use of a patterned spacer (either a Ga or Si substrate) placed in-between the substrate and its heater. The temperature distribution on such wafers is used to guide our experiments. A reflectivity measurement apparatus that is capable of mapping a 2 in. wafer with a 100 microns diameter resolution was built for diagnosing our wafers. In this first six-month report, our calculations, the various experimental results, and a discussion on future directions are presented.
- Publication:
-
Stanford Univ. Report
- Pub Date:
- December 1993
- Bibcode:
- 1993stan.reptR....C
- Keywords:
-
- Laser Cavities;
- Molecular Beam Epitaxy;
- Semiconductor Diodes;
- Semiconductor Lasers;
- Surface Emitting Lasers;
- Temperature Distribution;
- Bandwidth;
- Gallium Arsenides;
- Laser Arrays;
- Surface Temperature;
- Wafers;
- Lasers and Masers