UC Davis

Three-dimensional (3D) photonic packaging is a pivotal technology for integrating photonics components into compact and efficient optical systems. This dissertation presents advanced techniques for achieving cutting-edge 3D packaging, such as ultrafast laser inscription (ULI), optical phased arrays (OPAs), and metalenses. In ULI, we successfully demonstrated arbitrary vertical ULI waveguides within Eagle glass and an optical interposer, achieving a 0.62 dB/cm propagation loss. Further advancements led to a record-low loss of 0.16 dB/cm using germanium-oxide doped glass. We also employed a waveguide routing tool to demonstrate a 3D fan-in/fan-out device for multi-core fiber integration with SMF-28 fiber arrays. Furthermore, we presented a first 3D arrayed waveguide grating router (AWGR) operating at 1550 nm, created through ULI. Leveraging a multi-scan technique, we achieved a 399.1 GHz channel spacing, and a 2.02 nm 3 dB-passband. The integration of the AWGR with a fan-in/fan-out structure shows its versatility in 3D photonic integration. In optical beam steering, we developed a near-infrared (NIR) OPA with a 5 mm emitting area and 1.3 μm waveguide pitch, exhibiting 3.3° axial and over 40° lateral steering. Additionally, a mid-wave infrared (MWIR) OPA based on a germanium-silicon photonic platform achieved remarkable results, including 0.18° axial and 12.7° lateral beam steering. Furthermore, a commercial foundry was employed to fabricate 64 × 64 OPAs with integrated transistors, operating at wavelengths of 3.8 μm and 4.6 μm. For metalenses, we developed polarization-diversifying highly-dispersive metalenses tailored for four spectral bands (0.76 μm, 1.61 μm, 2.06 μm, and 2.32 μm) to enable compressive hyperspectral imaging. These metalenses with a 20 mm diameter boast impressive spectral resolving powers (10000, 5000, 4000, and 3571, respectively). Initial tests on a 2 mm metalens designed for a 2.06 μm wavelength validated its focusing capabilities, achieving a 46 % transmission efficiency. Additionally, the off-axis metalens displayed clear polarization splitting and a 12 μm focal spot shift during a 2 nm wavelength tuning.