Chapter 10 - Selective Growth Techniques and Their Application in WDM Device Fabrication

Abstract

This chapter discusses the selective growth techniques and their application in wavelength-division multiplexing (WDM) device fabrication. A selective area growth technique, in which a double heterostructure (DH) structure is grown on a mask-patterned planar substrate, is very useful, especially for fabricating integrated photonic devices used in WDM systems, because it enables bandgap energy control over the substrate. This bandgap energy control is mainly a result of diffusion in metal-organic vapor phase epitaxy (MOVPE). Selective MOVPE has many unique characteristics such as in-plane layer thickness control and bandgap-energy control, which is achieved simply by changing the mask pattern. Narrow-stripe selective MOVPE offers further advantages due to its direct waveguide formation capability, because no semiconductor mesa etching is needed to form active layers and optical waveguides. Consequently, highly uniform device characteristics can be obtained. This technique enables accurate control of Bragg lasing wavelengths for distributed feedback laser diode (DFB)-LDs, and wavelength-selectable light sources.