Parametric study of high-performance 1.55 μm InAs quantum dot microdisk lasers on Si

Area of Science:

• Optoelectronics
• Materials Science
• Semiconductor Devices

Background:

• Monolithic integration of lasers on silicon substrates is crucial for photonic integrated circuits.
• Quantum dots (QDs) offer advantages over quantum wells (QWs) for laser gain media due to suppressed inhomogeneous broadening.

Purpose of the Study:

• To perform a parametric study of high-performance microdisk lasers grown on silicon substrates.
• To compare the performance of quantum dot (QD) gain elements with quantum well (QW) gain elements in silicon microdisk lasers.
• To evaluate the temperature stability and performance of silicon-based QD microdisk lasers against those grown on indium phosphide (InP) substrates.

Main Methods:

• Fabrication and characterization of microdisk lasers with multiple layers of quantum dots (QDs) on on-axis (001) Si substrates.
• Comparative analysis of laser structures employing QDs versus quantum wells (QWs) on Si.
• Statistical comparison of silicon-based QD microdisk lasers with InP-based lasers.

Main Results:

• Optimized QD structures with seven layers achieved high gain and suppressed inhomogeneous broadening.
• QD lasers on Si exhibited superior performance compared to QW lasers on Si, with lower thresholds and better quantum efficiency.
• Si-based QD microdisk lasers showed comparable thresholds to InP-based lasers and demonstrated excellent temperature stability with a characteristic temperature of 277 K.

Conclusions:

• Monolithic integration of high-performance QD microdisk lasers on Si substrates is feasible at the 1550 nm telecom wavelength.
• QD gain elements provide significant advantages over QWs for silicon-based laser applications.
• The demonstrated temperature stability and performance offer a promising pathway for reliable silicon-based photonic devices.