Abstract
While III-V lasers epitaxially grown on silicon have been demonstrated, an efficient approach for coupling them with a silicon photonics platform is still missing. In this paper, we present a novel design of an adiabatic coupler for interfacing nanometer-scale III-V lasers grown on SOI with other silicon photonics components. The starting point is a directional coupler, which achieves 100% coupling efficiency from the III-V lasing mode to the Si waveguide TE-like ground mode. To improve the robustness and manufacturability of the coupler, a linear-tapered adiabatic coupler is designed, which is less sensitive to variations and still reaches a coupling efficiency of around 98%. Nevertheless, it has a relatively large footprint and exhibits some undesired residual coupling to TM-like modes. To improve this, a more advanced adiabatic coupler whose geometry is varied along its propagation length is designed and manages to reach ∼100% coupling and decoupling within a length of 200 μm. The proposed couplers are designed for the particular case of III-V nano-ridge lasers monolithically grown using aspect-ratio-trapping (ART) together with nano-ridge engineering (NRE) but are believed to be compatible with other epitaxial III-V/Si integration platforms recently proposed. In this way, the presented coupler is expected to pave the way to integrating III-V lasers monolithically grown on SOI wafers with other photonics components, one step closer towards a fully functional silicon photonics platform.
Highlights
Leveraging the well-established fabrication technology developed originally by the electronics industry, the domain of silicon photonics has seen an exponential growth over the last decade
We present a novel design of an adiabatic coupler for interfacing nanometer-scale III-V lasers grown on SOI with other silicon photonics components
In the case of monolithic integration the mask opening for growing the III-V nano-laser and the waveguide can be defined in the same patterning step as we will discuss in section 2, alleviating all issues in terms of alignment
Summary
Leveraging the well-established fabrication technology developed originally by the electronics industry, the domain of silicon photonics has seen an exponential growth over the last decade. This issue can be circumvented by coupling the light to the waveguide before it reaches the end of the III-V nano-ridge as we will discuss here. HHoowweevveerr,,aasstthheeddiirreeccttiioonnaallccoouupplleerriissvveerryysseennssiittiivveettoopprroocceessss vvaarriiaattiioonnss,, sseeccttiioonn 44 ddiissccuusssseess tthhee ddeessiiggnn ooff aa mmoorree rroobbuusstt lliinneeaarrllyy ttaappeerreedd aaddiiaabbaattiicc ccoouupplleerr FFiinnaallllyy,, sseeccttiioonn 55 ddeessccrriibbeess aa mmoorree aaddvvaanncceedd aaddiiaabbaattiicc ccoouupplleerr TThhee nnaannoo--rriiddggee ggrroowwtthh ssttaarrttss wwiitthh aa tthhiinn GGaaAAss nnuucclleeaattiioonn llaayyeerr ddeeppoossiitteedd iinn tthhee ttrreenncchheessffoolllloowweeddbbyyGGaaAAssggrroowwtthhiinnssiiddeeaannddoouuttssiiddeetthheettrreenncchh((FFiigg..33((dd)))).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
