Junction Temperature Measurement of InAs Quantum-Dot Laser Diodes by Utilizing Voltage–Temperature Method

Abstract

Junction temperature of InAs quantum-dot laser diodes (LDs) is measured by utilizing a forward voltage- temperature method. Although the forward voltage decrease with junction temperature increment is low, the linear relation between forward voltage and temperature clearly occurs. It is found that SiN <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> is more useful than SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> to keep junction temperature low. Injection current to shift the lasing wavelength from ground to excited state is increased over 200 mA by using SiN <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> instead of SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> as the insulating layer. As a result, ground state optical power is doubled.