Integrated Erbium Laser for Silicon Photonics

Technology

This technology is about integrated erbium-doped waveguide lasers designed for silicon photonic systems with low-loss, high-refractive-index-contrast photonic features. The distributed Bragg reflector laser cavities consist of silicon nitride waveguide and grating features defined by wafer-scale immersion lithography and a top erbium-doped aluminum oxide layer deposited as the final step in the fabrication process in order to be fully compatible with silicon process. The resulting inverted ridge waveguide yields high optical intensity overlap with the active medium for both the 0.98 μm pump and 1.5 μm laser wavelengths with high intensity. We obtain output powers of up to 5mW and show lasing at widely spaced wavelengths within both the C- and L-bands of the erbium gain spectrum (1536, 1561, and 1596 nm).  

Problem Addressed      

For production-level fabrication of integrated lasers on silicon, it is desirable to define the laser cavities using standard silicon processing methods. However, rare-earth-doped materials are incompatible with existing silicon production lines in semiconductor industry. Here we developed a highly beneficial process flow in which the erbium-doped layer can be deposited in a back-end manner.  

Advantages      

• Up to 5mW of output power and shows lasing in both the C- and L- bands
• Covering a wavelength range more than two times larger than that previously shown using erbium-doped aluminum oxide
• A silicon-compatible process used to fabricate low-loss, high-refractive-index-contrast photonic features with high resolution
• Easy to integrate with other Si3N4 passive components on silicon chips  

Publications

"C- and L-band Erbium-doped Waveguide Lasers with Wafer-scale Silicon Nitride Cavities." Optics Letters 2013.