Publications

Abstract not provided.

We demonstrate for the first time waveguide integrated cascaded germanium photodetector arrays operated as photocells. We characterize several different array designs, and discuss their effects on voltage and photocurrent performance parameters.

We present a novel design of a III-V-on-silicon heterogeneously integrated tunable ring laser, achieving >80 nanometers of tuning bandwidth, the widest conceived using only two rings, fostering many applications such as spectroscopy and beam steering.

Hybrid bonded silicon nitride thin-film lithium niobate (TFLN) Mach-Zehnder modulators (MZMs) at 1310 nm were designed with metal coplanar waveguide electrodes buried in the silicon-on-insulator (SOI) chip. The MZM devices showed greatly improved performance compared to earlier devices of a similar design, and similar performance to comparable MZM devices with gold electrodes made on top of the TFLN layer. Both devices achieve a 3-dB electro-optic bandwidth greater than 110 GHz and voltage-driven optical extinction ratios greater than 28 dB. Half-wave voltage-length products ( Vπ L) of 2.8 and 2.5 Vċ cm were measured for the 0.5 and 0.4 cm long buried metal and top gold electrode MZMs, respectively.

TFLN/silicon photonic modulators featuring active silicon photonic components are reported with a Vπ of 3.6 Vcm. This hybrid architecture utilizes the bottom of the buried oxide as the bonding surface which features minimum topology.

The extreme miniaturization of a cold-atom interferometer accelerometer requires the development of novel technologies and architectures for the interferometer subsystems. Here, we describe several component technologies and a laser system architecture to enable a path to such miniaturization. We developed a custom, compact titanium vacuum package containing a microfabricated grating chip for a tetrahedral grating magneto-optical trap (GMOT) using a single cooling beam. In addition, we designed a multi-channel photonic-integrated-circuit-compatible laser system implemented with a single seed laser and single sideband modulators in a time-multiplexed manner, reducing the number of optical channels connected to the sensor head. In a compact sensor head containing the vacuum package, sub-Doppler cooling in the GMOT produces 15 μK temperatures, and the GMOT can operate at a 20 Hz data rate. We validated the atomic coherence with Ramsey interferometry using microwave spectroscopy, then demonstrated a light-pulse atom interferometer in a gravimeter configuration for a 10 Hz measurement data rate and T = 0–4.5 ms interrogation time, resulting in Δg/g = 2.0 × 10−6. This work represents a significant step towards deployable cold-atom inertial sensors under large amplitude motional dynamics.

Abstract not provided.

Abstract not provided.

A compact radio frequency (RF) photonic receiver consisting of several photonic integrated circuits (PIC) that performs channelization and simultaneously downconverts the signal is described. A technique is also presented to adjust the phase shifters of the arrayed waveguide grating channelizer without direct phase measurements.

We demonstrate the first silicon photonic single-sideband (SSB)modulator with dual-parallel Mach-Zehnder modulators (MZMs)operating near 1550 nm with a measured carrier suppression of 27 dB and at least 12 dB sideband suppression at 1 GHz.