Three-dimensional integration of VCSEL-based optoelectronics

Abstract

A monolithic optoelectronic device structure with the potential to enable VCSEL-based photonic integrated circuits on GaAs is presented. Using integrated diffraction gratings, the device structure enables the optical output of VCSELs to be coupled to an internal horizontal waveguide, while the optical signals in the waveguide are tapped off to resonant cavity detectors. Since horizontal waveguides are used to route the optical signals between devices, the output mirror transmission of the VCSELs can be eliminated, although we have chosen to retain a small amount of transmission in the top DBR to enable on-wafer testing. The design and fabrication of the monolithically integrated structure, including epitaxial regrowth, is discussed and initial device characteristics are presented.

Highly-integrated, VCSEL-based optoelectronics for fault-tolerant, self-routing optical networks

“…If properly designed, a strong diffraction efficiency approaching 50% in each lateral direction can be achieved by having the partial diffracted optical fields add coherently and constructively during successive passages of light through the resonance cavity. This was first demonstrated [7,8] by using an all-epitaxially-grown AlGaAs/GaAs vertical-cavity resonance structure in which a semiconductor optical waveguide containing a waveguide-grating coupler (WGC) is embedded within the resonance cavity. By allowing the in-plane coupling of light from VCSELs into the optical waveguides, this technology approach enables the monolithic integration of surface-normal devices such as VCSELs and resonance-enhanced photodetectors (REPDs) [9], which communicate via the embedded waveguide.…”

“…To overcome this obstacle, an effective means is needed that can couple light efficiently from the vertical cavity of the VCSEL into a horizontal waveguide. One promising approach [7,8] is to embed an optical waveguide within the resonance cavity of the VCSEL, and then utilize diffraction gratings to couple light from the VCSEL cavity into the waveguide. If properly designed, a strong diffraction efficiency approaching 50% in each lateral direction can be achieved by having the partial diffracted optical fields add coherently and constructively during successive passages of light through the resonance cavity.…”

Integrated Waveguide-Grating-Coupled VCSEL/Photodetector Arrays with High Coupled Power for Dense High-Speed Interconnects

“…Vertical-cavity surface-emitting lasers (VCSELs) have a great potential for integration with other components such as photodetectors through a waveguide grating coupler (WGC) to form optoelectronic integrated circuits on a single platform [1]. In our early work, we demonstrated a monolithic VCSEL structure with bidirectional coupling to an internal horizontal waveguide by means of an embedded diffraction grating [2].…”

Heterogenous integrated waveguide-coupled VCSEL-based optical interconnects

“…If properly designed, a strong diffraction efficiency approaching 50% in each lateral direction can be achieved by having the partial diffracted optical fields add coherently and constructively during successive passages of light through the resonance cavity. This was first demonstrated [1,2] by using an all-epitaxially-grown AlGaAs/GaAs vertical-cavity resonance structure in which a semiconductor optical waveguide containing a waveguide-grating coupler (WGC) is embedded within the resonance cavity. In this early work [2], a monolithic VCSEL structure achieved bidirectional coupling to an internal horizontal waveguide by means of embedded diffraction grating couplers.…”

“…To overcome this obstacle, an effective means is needed that can couple light efficiently from the vertical cavity of the VCSEL into a horizontal waveguide. One promising approach that has been proposed [1,2] is to embed an optical waveguide within the resonance cavity of the VCSEL, and then utilize diffraction gratings to couple, i.e., to diffract light from the VCSEL cavity into the waveguide. If properly designed, a strong diffraction efficiency approaching 50% in each lateral direction can be achieved by having the partial diffracted optical fields add coherently and constructively during successive passages of light through the resonance cavity.…”