Inclined emitting slotted single-mode laser with 1.7° vertical divergence angle for PIC applications.

Area of Science:

• Photonics
• Optoelectronics
• Materials Science

Background:

• Photonic integrated circuits (PICs) require efficient on-chip light sources.
• Direct coupling of laser light into silicon photonic platforms is challenging.
• Existing laser technologies often have limitations in beam divergence and integration compatibility.

Purpose of the Study:

• To propose and demonstrate a new type of single-mode slotted laser for on-chip light sources.
• To achieve direct coupling of an inclined laser beam into silicon surface gratings.
• To develop an integrated light source with low vertical beam divergence.

Main Methods:

• Design and fabrication of a single-mode slotted laser incorporating a specially distributed microstructure.
• Experimental characterization of the laser's emission angle, divergence, side mode suppression ratio, and output power.
• Integration strategy involving direct coupling of the inclined beam into silicon surface gratings.

Main Results:

• A III-V laser with a 54.6° inclined emission angle and a 1.7° vertical divergence angle was successfully fabricated.
• The laser achieved a side mode suppression ratio greater than 45 dB.
• Continuous wave output power reached 6.5 mW at room temperature.

Conclusions:

• The developed microstructured single-mode laser with an inclined emission and low divergence angle is a novel advancement.
• This laser technology enables efficient on-chip light source integration in photonic integrated circuits.
• The findings represent a significant step towards practical silicon-based photonic integrated light sources.