Arrayed narrow linewidth erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss silicon-nitride...

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Semiconductor Devices

Background:

• Integrated photonics requires efficient light sources on silicon platforms.
• Erbium-doped materials are crucial for optical amplification and lasing in the telecommunication C-band.
• Silicon nitride (Si3N4) offers ultra-low loss and CMOS compatibility for photonic integrated circuits.

Purpose of the Study:

• To demonstrate erbium-doped waveguide-distributed feedback (WG-DFB) lasers on an ultra-low-loss Si3N4 platform.
• To investigate the performance characteristics of these integrated lasers.
• To assess the feasibility of Si3N4 as a host material for rare-earth-doped lasers.

Main Methods:

• Fabrication of Si3N4 waveguides with sidewall gratings using 248 nm stepper lithography.
• Deposition of a reactive co-sputtered erbium-doped aluminum-oxide layer for optical gain.
• Characterization of lasing output, including wavelength range, output power, linewidth, and side-mode suppression ratio.

Main Results:

• Lasing output observed over a 12 nm wavelength range (1531-1543 nm) from an array of five separate lasers.
• Achieved output powers of 8 μW.
• Obtained lasing linewidths of 501 kHz.
• Confirmed single-mode operation with side-mode suppression ratios exceeding 35 dB for all designs.

Conclusions:

• Successful demonstration of erbium-doped WG-DFB lasers on an ultra-low-loss Si3N4 platform.
• The results highlight the potential of Si3N4 for integrated rare-earth-doped photonic devices.
• The achieved performance metrics indicate suitability for various integrated photonic applications, including optical communication and sensing.