Ultrawide-bandwidth, superluminescent light-emitting diodes using InAs quantum dots of tuned height.

Area of Science:

• Optoelectronics
• Semiconductor devices
• Quantum dot technology

Background:

• Superluminescent light-emitting diodes (SLEDs) are crucial for broadband light sources.
• Quantum dot (QD) technology offers tunable optical properties for advanced SLEDs.
• Understanding thermal effects is key to optimizing SLED performance.

Purpose of the Study:

• To report on an ultrawide-bandwidth SLED utilizing multiple layers of quantum dots with tuned heights.
• To investigate the influence of thermal effects on SLED performance, particularly the superluminescent phenomenon.
• To characterize the optical and power output of the developed SLED under continuous-wave (cw) and pulsed-mode operations.

Main Methods:

• Fabrication of an SLED device incorporating multiple layers of precisely height-tuned quantum dots.
• Experimental operation of the SLED under both continuous-wave (cw) and pulsed-mode conditions.
• Measurement of the device's 3 dB bandwidth, central wavelength, and output power characteristics.

Main Results:

• The SLED demonstrated an ultrawide 3 dB bandwidth of 190 nm centered at 1020 nm under cw conditions.
• The superluminescent phenomenon was observed exclusively under pulsed-mode operation, attributed to thermal effects.
• Maximum output powers of 0.54 mW (cw) and 17 mW (pulsed) were achieved, highlighting significant pulsed operation enhancement.

Conclusions:

• The developed multilayered quantum dot SLED achieves ultrawide bandwidth and high output power.
• Pulsed-mode operation is essential for observing the superluminescent effect in this device due to thermal management.
• This SLED technology holds promise for applications requiring broadband, high-power light sources.