Description: The objective of the Phase II extension proposal is to develop three-dimensional mid-infrared (mid-IR) multimode and single-mode waveguides inside Chalcogenide glasses operating at a wavelength of 4.7 µm. This technology is based on Ultrafast Laser Inscription (ULI) technology. ULI is a one-step cost-effective fabrication process, which is a fast, scalable method with easier process control or repeatability. It allows for rapid prototyping in a wide range of transmissive mid-IR waveguides. We aim to advance the technology readiness level from level 2 to 3. This project provides a building block for integrated photonic lanterns are formed by adiabatically converting a multi-mode waveguide to a number of single-mode waveguides. The fabricated waveguides and the subsequent photonic lanterns in a later phase of this project can be integrated as beam reshaping and delivery subsystem to larger systems such as the Photonic Integrated Circuit TUned for Reconnaissance and Exploration (PICTURE). The proposed mid-IR waveguide structures further enable the fabrication of three-dimensional beam combiners, tapper waveguides, integrated photonic lanterns, null interferometers, and others. The work plan contains five main tasks the corresponding deliverables. Task 1 consists of deploying an experimental station to characterize waveguides written in IG2. Tasks 2 and 3 will focus on the fabrication and characterization of single-mode waveguides. Tasks 4 and 5 will focus on the fabrication and characterization of multimode waveguides. The fabrication and characterization will be an iterative process till the optimum laser process parameters are determined. The schedule is laid out in Table 1 of the proposal. The proposed work builds on the successful ULI of waveguides inside Nd: YAG and Lithium Niobate crystals during the STTR Phase I and II, and the successful ULI demonstration inside glass materials by the same offeror (Aktiwave and Rochester Institute of Technology).

Benefits: This project provides a building block for integrated photonic lanterns (PL). The fabricated waveguides and the subsequent PLs in a later phase of this project can be integrated as beam reshaping and delivery subsystem to larger systems such as the Photonic Integrated Circuit TUned for Reconnaissance and Exploration. It will also be useful in a variety of emerging areas, including free-space laser communications, mid-infrared heterodyne spectroscopy, and nulling interferometer.

The Mid-IR waveguide enabled photonic devices will allow for • Monitoring of indoor & outdoor pollution. • Monitoring of healthhazardous species and pollution sources for climate studies and industrial processes • Biomedical applications, e.g., noninvasive breath analysis of ethylene and large biomarker molecules for disease assessment.