Efficient Active-to-Passive Light Coupling of InGaAsP/InP Laser Using Subwavelength Coupler

Abstract

We propose a subwavelength coupler for efficient light coupling from an InGaAsP/InP laser to a passive waveguide. The active-to-passive coupling device is designed on the asymmetric twin waveguide (ATG) platform with two InGaAsP layers: one is used as the laser active layer, and the other with a wider band gap is used as the guiding layer of the passive waveguide. By introducing subwavelength trenches in the active InGaAsP layer, the subwavelength coupler is designed to provide a gradual effective index transition region, and it couples the light between the vertically separated active and passive layers. Simulation result shows that coupling efficiency of 86.5% is achieved at a length of only 31 m.

On-chip metamaterial-enabled high-order mode-division multiplexing

“…Different from previous phase-matching approaches, the coupling strength in the proposed scheme can be effectively tailored by engineering the parameters of the GIM waveguides. This scheme has been proposed to achieve an inter-layer coupling between the active InP layer and the passive optical layer 44 . Adiabatic coupling enabled by the GIM coupler can help to relax the stringent phase matching condition encountered by conventional DCs and provides a new degree of freedom for designing an efficient mode coupling process and achieving a record 16-channel (TE0–TE15) on-chip MDM device 45 .…”

“…This scheme has been proposed to achieve an inter-layer coupling between the active InP layer and the passive optical layer. 44 Adiabatic coupling enabled by the GIM coupler can help to relax the stringent phase matching condition encountered by conventional DCs and provides a new degree of freedom for designing an efficient mode coupling process and achieving a record 16-channel (TE 0 -TE 15 ) on-chip MDM device. 45 Here, we conduct a detailed theoretical analysis, provide a full characterization of the device, and carry out a high-speed data transmission experiment.…”