InAs quantum dots, typically grown on GaAs, are a potential candidate for 1.3 µm lasers for use in silica optical fiber-based local and metro data communications systems. In this application, lasers are required to operate in road-side cabinets over a broad temperature range without the need for expensive temperature control. In QD lasers, temperature sensitivity can be reduced by enhancing the energy level separation.
PL spectra taken at high and low powers allow the identification of the confined states of the quantum dot and the surrounding wetting layer, offering essential information on the internal electronic structure including confinement potential depth and energy spacing.
DMc150 Double Monochromator
A cryogenically-cooled QD sample is excited with a 532 nm DPSS laser. The ensuing photoluminescence was analyzed by an InGaAs photodiode and a Bentham DMc150 double monochromator, providing high sensitivity and excellent stray light rejection to allow the resolution of weak features even at extremely high excitation levels of MW/cm2.
PL spectra of 1.3 µm emitting QD sample at low and high power
The ground state dominates at low power, whereas at high excitation power, the ground, 1st, 2nd, 3rd and wetting layer are clearly visible.
(Images and application information courtesy of Dr David Childs, University of Sheffield)
This information has been sourced, reviewed and adapted from materials provided by Bentham Instruments Limited.
For more information on this source, please visit Bentham Instruments Limited.