Commercial Production of Low-Loss Quantum Frequency Conversion and Electro-Optical Modulation Devices Enabled by Wafer-Level Processing of Reverse-Proton-Exchange Lithium Niobate Waveguides

Quantum optical networks will require all optical signal processing that is enabled by lithium niobate-based components. While many of these components are commercially available, they are not optimized for the ultra-low optical losses required for quantum applications. This program will develop refined processing techniques to fabricate ultra-low loss lithium niobate- based components, initially targeting quantum frequency conversion and electro-optic modulation applications. In this SBIR program, AdvR will optimize wafer level reverse proton exchange for scalable production of ultra-low loss waveguides. While this technique has been demonstrated to lower loss at the chip level, it is not currently implemented at the wafer level due to thermal stresses causing wafer breakage. The phase I program firmly established the feasibility of performing wafer level reverse proton exchange at AdvR. In the phase I project, AdvR developed the equipment, process, and procedure necessary to perform reverse proton exchange at the wafer level. AdvR demonstrated wafer level reverse proton exchange of several X-cut and Z-cut lithium niobate wafers. In the phase II, AdvR will continue to refine this process, and apply the technology towards quantum frequency conversion and electro-optic modulation applications. In this phase II project, AdvR will continue to refine the wafer level reverse proton exchange process for scalable production of ultra-low loss waveguides. AdvR will apply this processing to quantum frequency conversion devices for entanglement preserving conversion between the visible/Near-IR and telecom bands. Additionally, AdvR will fabricate electro-optic modulators for ultra-low loss modulation applications. This is well aligned with DOE needs in all optical signal processing and AdvR’s expertise in waveguide fabrication, packaging, and characterization. Initial applications for this technology will be quantum networking systems that require ultra-low loss all optical signal processing. While near-term commercial opportunities primarily involve supporting research and development staff, future implementation in this field may be much larger. Additionally, classical applications of electro-optic and frequency conversion devices may also benefit from ultra-low optical loss and represents another potential commercial application.