Waveguide-coupled metal-clad cavity with integrated feedback stub

Abstract

We propose a wavelength-scale metal-clad III–V semiconductor cavity coupled to silicon-on-insulator (SOI) waveguide with integrated feedback stub for external tuning of the Q factor. We consider a typical wavelength-scale metal-clad InP/InGaAs cavity integrated on a SOI waveguide and demonstrate more than 5-fold Q-factor improvement in agreement with that predicted by the coupled-mode theory. From additional thermal analysis, we prove that improved heat dissipation can be realized by engineering the layer thicknesses without sacrificing much of the optical performance.

Design and Analysis of Asymmetric Capsule-Shaped Metallic Cavities for Unidirectional Waveguide Coupling

“…In last decade, a variety of metallic semiconductor cavity lasers has been proposed and studied for their promising applications, such us photonic integrated circuits (PICs), on-chip optical interconnection, optical communication, and so on [1][2][3][4][5]. Compared with the traditional waveguide-coupling scheme of semiconductor lasers, the optical energy inside the metallic cavity laser is generally coupled out through the waveguide underneath the bottom of the resonant cavity, where is free of metallic cladding [6][7][8][9]. Generally, increasing the coupling energy of the laser waveguide is of importance from practice point of view, but it contributes to higher radiation loss and thus lowers down quality (Q) factor of the metallic semiconductor cavity [6,7].…”

“…Among the current metallic semiconductor cavity lasers, there are two main types of cavity structures including cylindrical cavity based on whispering-gallery mode [18][19][20] and rectangular cross-section cavity based on Fabry-Perot mode [21][22]. At present, the scheme of waveguide coupling from above types of metallic semiconductor lasers is mainly to embed the waveguide structure in the substrate layer [6][7][8][9], which couples the evanescent field of the resonance mode from the cavity into the waveguide. And by optimizing the geometric structure and spatial position of the waveguide, the coupling efficiency can be increased effectively.…”

“…Therefore, unidirectional waveguide-coupling output are limited. To achieve unidirectional output, one reported method is to construct the waveguide only at one end of the cavity [7,8]. However, this asymmetric waveguide structure limits the potential applications of the lasers, such as signal conversion and modulation.…”