Measurements of I–V characteristics in InAs/InP quantum dot laser diode

Abstract

The current–voltage (I–V) characteristics are reported of an InAs/InP quantum dot laser diode operating under the continuous wave mode. The laser diode emits a wavelength of 1.55 µm at a temperature of 293 K. The maximum operation temperature reaches 343 K. As the injection current is increased, a nonlinear relationship between ln(I) (where I is the injection current) and applied voltage is observed. When the operating temperature is increased, the forward voltage and turn-on voltages decrease. The voltage is found to drop linearly with operation temperature. However, the temperature efficiency of forward voltage (slope: ) is nonlinear with the applied current. In the injection current range from 5 to 400 mA, the temperature efficiency of forward voltage decreases from −1.27 mV/K to −6.68 mV/K. The dV_F /dT shows a linearity with the function ln(I), which agrees well with the simplified Shockley equations. In addition, the band gap of the laser diode is obtained by fitting the forward voltage with operating temperature at low injection current.

Keywords:

• quantum dot laser diode
• current–voltage characteristics
• energy band gap

Acknowledgements

This work was financially supported by the National Natural Foundation of China (Grant Nos. 61204058, 10990103, 61021064 and 60976015), the Natural Foundation of Guangdong province (Grant No. S2011040001330) and by the Foundation of Shenzhen Institute of Information Technology (Grant No. CXTD003).