Heterogeneous tantala photonic integrated circuits for sub-micron wavelength applications

TL;DR

This paper presents heterogeneous photonic integrated circuits at 980 nm with high-yield wafer-scale bonding, enabling diverse active components and laser functionalities crucial for compact quantum sensors and related applications.

Contribution

Development of wafer-scale bonded heterogeneous PICs at 980 nm with high yield, integrating over 1300 active components and demonstrating laser and wavelength control functionalities.

Findings

High-yield (>95%) wafer-scale bonding process.

Integration of >1300 active components on a 3-inch wafer.

Demonstration of on-chip lasers with >250 GHz tuning range.

Abstract

Atomic and trapped-ion systems are the backbone of a new generation of quantum-based positioning, navigation, and timing (PNT) technologies. The miniaturization of such quantum systems offers tremendous technological advantages, especially the reduction of system size, weight, and power consumption. Yet, this has been limited by the absence of compact, standalone photonic integrated circuits (PICs) at the wavelengths suitable for these instruments. Mobilizing such photonic systems requires development of fully integrated, on-chip, active components at sub-micrometer wavelengths. We demonstrate heterogeneous photonic integrated circuits operating at 980 nm based on wafer-scale bonding of InGaAs quantum well active regions to tantalum pentoxide passive components. This high-yield process provides > 95 % surface area yield and enables integration of > 1300 active components on a 76.2 mm (3 inch) silicon wafer. We present a diverse set of functions, including semiconductor optical amplifiers, Fabry-Perot lasers, and distributed feedback lasers with 43 dB side-mode suppression ratio and > 250 GHz single-mode tuning range. We test the precise wavelength control and system level functionality of the on-chip lasers by pumping optical parametric oscillation processes in microring resonators fabricated on the same platform, generating short-wavelength signals at 778 nm and 752 nm. These results provide a pathway to realize fully functional integrated photonic engines for operation of compact quantum sensors based on atomic and trapped-ion systems.