Superluminescent diode. It is an edge-emitting semiconductor light source that operates by amplified spontaneous emission rather than stimulated emission in a resonator. It provides the high spatial coherence and brightness of a laser diode but with the broad optical bandwidth and low temporal coherence of an LED, making it ideal for optical coherence tomography and fiber optic gyroscopes.
The SLD gives us a nice broad spectrum without the speckle issues we were getting from the laser diode.
Also heard as
- SLED
Related terms
Laser diode
A semiconductor laser driven by electric current, used as a light source in its own right and to pump other lasers.
ASE
Amplified Spontaneous Emission: random spontaneous photons amplified in a gain medium, a broadband noise background.
Speckle
The grainy pattern of bright and dark spots seen when coherent laser light scatters off a rough surface.