Fabry-Perot LD Chip Constructione

LD Chip Construction

The Fabry-Perot LD is composed of an active layer (light emitting layer) sandwiched between N/P cladding and two mirrors used as end faces.

Since the cladding is a material with a bandgap larger than that of the active layer, carriers (electrons and holes) are confined energy-wise. Also, since the refractive index is smaller than the active layer, light is trapped within the active layer. (Same principle as optical fiber)

Both the active layer and cladding are created by epitaxial growth that can be controlled at the nano level, while the stripe (electrode) is fabricated via photolithography which can be controlled on the micron order.

[LD Chip Construction]

Fabry-Perot LD:

Features the simplest structure for a laser diode.

Epitaxial Growth:

A thin-film crystal growth technique that involves carrying out growth on a crystal that will become the substrate, with the crystal arrangement aligned with the substrate crystal plane.

Photolithography:

A method for generating patterns from exposed and unexposed sections by exposing a surface coated with photosensitive material.