Optical properties of a GaAlAs superluminescent diode

The optical properties of a GaAlAs superluminescent diode (SLD) are described. The spectra of this device exhibit a large number of longitudinal modes. The coupling efficiency into a 0.23 NA 50 μm diameter graded index fiber is ∼ 30 percent. The current required for constant light output at a temperature
T
can be written as
I(T) \sim I_{0} \cdot \exp (T/T_{2})
where
T_{2} \sim 120
K. A model of the SLD is described.