Optical waveguides in crystalline dielectric materials produced by femtosecond‐laser micromachining

TLDR

Femtosecond‑laser micromachining enables efficient direct 3‑D fabrication of transparent optical materials, allowing the creation of waveguides with diverse configurations in a wide range of optical substrates. This review examines femtosecond‑laser micromachining of crystalline dielectric materials, covering fabrication, characterization, and applications of waveguiding structures in optical crystals and ceramics. The authors survey recent advances in direct femtosecond‑laser inscription of waveguides in crystalline dielectrics, analyzing fabrication parameters, material responses, and characterization techniques. A brief outlook highlights several promising future directions for femtosecond‑laser‑fabricated waveguides in optical crystals and ceramics.

Abstract

Abstract Femtosecond‐laser micromachining (also known as inscription or writing) has been developed as one of the most efficient techniques for direct three‐dimensional microfabrication of transparent optical materials. In integrated photonics, by using direct writing of femtosecond/ultrafast laser pulses, optical waveguides can be produced in a wide variety of optical materials. With diverse parameters, the formed waveguides may possess different configurations. This paper focuses on crystalline dielectric materials, and is a review of the state‐of‐the‐art in the fabrication, characterization and applications of femtosecond‐laser micromachined waveguiding structures in optical crystals and ceramics. A brief outlook is presented by focusing on a few potential spotlights.