Study of Group III-V Waveguides on Sapphire Platform for Photonic Integrated Circuits

TL;DR

This paper systematically studies the performance of Group III-V straight waveguides on sapphire, demonstrating low-loss optical waveguides across multiple wavelengths, which is crucial for integrated photonic circuits on sapphire platforms.

Contribution

It provides the first comprehensive analysis of Group III-V waveguides on sapphire, including loss calculations at key telecom wavelengths, aiding the development of integrated photonic components.

Findings

Calculated waveguide losses: 0.32 dB/cm at 1330 nm, 0.67 dB/cm at 1550 nm, 0.70 dB/cm at 2000 nm.

High refractive index contrast enables low-loss waveguides over broad wavelengths.

Results support the development of passive photonic components on sapphire platforms.

Abstract

Photonic integrated circuits (PICs) have been acknowledged as the promising platforms for the applications in data communication, Lidar in autonomous driving vehicles, innovative sensor technology, etc. Since the demonstration of optical components individually, integration of both electronics and photonics for functional devices on a common platform has been a key technology driver enhancing the stability and scalability of integrated photonic technologies. Recently, we proposed to use sapphire as a high-performance PIC platform, which enables a fully integrated solution to include a complete set of components with light source, modulator, light detection, passive devices, silicon on sapphire control circuit all-in-one sapphire platform to achieve high-performance low-cost mixed-signal optical links. In parallel to developing ac-tive components such as group III-V lasers on sapphire, in this work, the performance of group III-V straight waveguides on sapphire was systemically studied. The refractive indices contrast between GaAs, InP, GaSb, and sapphire are sufficiently high to achieve low loss over a broad optical wavelength. The calculated loss at wavelengths of 1330 nm, 1550 nm, and 2000 nm for the GaAs, InP, and GaSb rib waveguides are 0.32 dB/cm, 0.67 dB/cm, and 0.70 dB/cm, re-spectively. Since the fundamental element to construct all passive building blocks is the straight waveguide, results from this work would allow us to assess other basic passive building blocks.