High characteristic temperature 1.5 µm wavelength laser diode via Sb-based quantum dots in quantum wells

ABSTRACT

The advent of laser diodes in the 1.55 µm wavelength region is becoming a hot topic in the field of telecommunications. The growth of strain-engineered Sb-based multi-stacks quantum dots (QDs) on GaAs by molecular beam epitaxy (MBE) is advantageous to restrain its drawback of self-absorption and thus beneficial for preparing efficient laser diodes (LDs). Moreover, owing to a strong electronic coupling between the QDs layers and the quantum wells (QWs), strain-engineered QDs introducing antimony (Sb) with emission wavelength up to 1.5 µm were achieved at room temperature. The p-type doping can substantially increase the QD laser’s ground state gain at room temperature. Based on this simple process, high efficient LD was obtained. The LD was fabricated with a cavity length of 1000 μm and a stripe width of 100 μm. The output performance was achieved with threshold current densities of the device as low as 135 A/cm², and with high Characteristic Temperatures of 118 K or higher in the temperature range between 20°C and 80°C. The continuous wave operating up to 32 mW were achieved at room temperature (RT).

KEYWORDS:

• Quantum dots (QDs)
• laser diodes (LDs)
• strain-engineered
• antimony (Sb)

Additional information

Funding

We acknowledge financial support from the National Natural Science Foundation (NSFC) of China [grant numbers 61774025, 61430037, 11474036]. The financial support of the Department of Jilin Provincial Science and Technology [grant numbers 20140520139JH, 20170520157JH, 20170414016GH, 2015174, 201524], and Chinese Postdoctoral Support [grant number 2016M60139] is also acknowledged.