Four-wavelength microdisk laser array laterally coupled with a bus waveguide

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Lasers
• Integrated Optics

Background:

• Microdisk lasers offer compact and efficient light sources.
• Laterally coupled structures are crucial for integrated photonic circuits.
• Achieving stable multi-wavelength emission is essential for WDM systems.

Purpose of the Study:

• To numerically and experimentally demonstrate a four-wavelength microdisk laser array.
• To investigate the coupled-mode characteristics and scattering loss.
• To analyze the thermal effects on lasing mode tuning.

Main Methods:

• Numerical simulation using 2D finite-difference time-domain (FDTD) technique.
• Fabrication of an AlGaInAs/InP microdisk laser array using photolithography and ICP etching.
• Experimental characterization of continuous-wave (CW) electrically injected operation.

Main Results:

• Demonstrated continuous-wave electrically injected operation at room temperature with a threshold current as low as 3 mA.
• Achieved four-wavelength lasing operation with 3-4 nm wavelength intervals and side-mode suppression ratios > 25 dB.
• Investigated the influence of heating and thermal crosstalk on lasing mode wavelength tuning.

Conclusions:

• The demonstrated microdisk laser array is a viable component for multi-wavelength optical systems.
• The study provides insights into the design and performance of coupled microdisk lasers.
• Understanding thermal effects is critical for stable multi-wavelength operation in such devices.