Two-Waveguide Approach for Monolithic Active/Passive Photonic Integration on GaAs

<p dir="ltr">Three different GaAs/AlGaAs epistacks were optimised to enable both active and passive photonic devices to be fabricated on the same monolithic structure. This is achieved by using two vertically stacked GaAs waveguides, the top of which contains InAs quantum dots to generate light. The two waveguides are evanescently coupled and decoupled by changing either the etch depth of the ridge, or by the selective oxidation of Al_0.98Ga_0.02As layers. </p><p dir="ltr">The dataset gives the results for three epistacks: The first is vertically symmetric from the center of the two waveguides, and coupling is achieved by a change of etch depth. The second contains Al_0.98Ga_0.02As layers which break the symmetry, and coupling is again achieved by a change of etch depth. In the third stack, the Al_0.98Ga_0.02As layers are selectively oxidised, with the etch depth constant. The coupling is achieved where the layers are left unoxidised.</p><p dir="ltr">Dataset_1 and Dataset_4 give the change in effective index of the TE0 modes in each waveguide, based on their etch depth, and distance from the oxidised layers respectively. This data was simulated using the finite difference method from FIMMWAVE software by Photon Design Ltd.</p><p dir="ltr">Dataset_2, Dataset_3, and Dataset_5 give the power output after coupling vs the coupling length for the first, second, and third epistacks. This data was simulated using the eigenmode expansion method from FIMMPROP software by Photon Design Ltd.</p><p dir="ltr">The file 'README.docx' contains more details on each of the specific files.</p>