In this work, two-photon polymerization three-dimensional laser writing is used to integrate a microlens on the surface of a single mode polarization-stable vertical-cavity surface-emitting laser (VCSEL) to be used as a current-driven tunable source in a compact optical guided-wave gas sensor. The writing conditions are optimized to enable on-demand room temperature and single-step fabrication at a post-mounting stage. We show that a writing time of 5 min is sufficient to fabricate a microlens that efficiently reduces the VCSEL beam divergence, without significant change on its emitted power or polarization stability. The lens addition reduces the spectral available range at high injection currents. A two-dimensional optical modeling of the gain characteristics is used to explain this effect and a new transverse design is proposed to avoid this issue.

Nanoimprinting of surface-relief grating-based waveguides has the potential to produce one of the industry-leading augmented reality (AR) smart glasses, but there are still many challenges in the design, scaling, and reproducibility of these imprinted waveguides. A promising path toward mass manufacturing of optical waveguide combiners is via large-area nanoimprinting. Here, we present the complete value chain with partners involved throughout the process: from design, mastering, and materials to imprinting and metrology, to prove that this method improves not only the manufacturing throughput but also the waveguide quality. We demonstrate that the replication and image quality are true to the intended design using large area, high refractive index (n = 1.9), square (300 mm × 300 mm) glass substrates with high-refractive index resins (n = 1.9). This is shown to be valid for over 100 replications and for large area nanoimprinting (Gen5, 1100 mm × 1300 mm). Our goal is to demonstrate a viable path toward high-volume and low-cost manufacturing of AR waveguides based on surface relief gratings.