Do SLEDs Have a Bright Future?

Superluminescent light emitting diodes (SLEDs) are similar to laser diodes, but have a beam-like output like LEDs. They emit broadband light in all directions and narrowband light with a well-focused beam. SLED applications include fiber optic gyroscopes (FOG) and optical coherence tomography (OCT), a near-infrared interferometric technique for medical imaging. Today, OCT is used to image the retina and cornea in the human eye.

Commercially-available red-infrared SLEDs use indium phosphide (InP) and gallium arsenide (GaAs) technologies. Researchers in Switzerland, however, have used metal-organic chemical vapor deposition (MOCVD) to develop SLED layers made of indium gallium nitride (InGaN). These new nitride SLEDs feature better blue-violet capabilities and good thermal performance.

Superluminescent light emitting diodes provide high output power, large bandwidth, and low residual spectral ripple; however, they are sensitive to electrostatic discharges and current spikes. Are SLED really the broadband light source for the imaging applications of the future?

Sources: Semiconductor Today, Exalos and RP Photonics