Waveguide-like structures written in transparent polycrystalline ceramics with an ultra-low fluence femtosecond laser

摘要: We present a laser processing study of optically transparent ytrria stabilized zirconia (YSZ) ceramics (ZrO2-8 mol. % Y2O3) using unamplified femtosecond (fs) pulses few nJ and high repetition rate (70 MHz). The were fabricated current activated pressure assisted densification (CAPAD) have fine grain size minimal porosity, producing material. Irradiation fs caused permanent changes in the optical properties irradiated zone. These written structures found to confine He-Ne light (632 nm) effect functioning as waveguide like into YSZ remarkably low per-pulse energy (5nJ). number passes with i.e total incident per unit area was significantly affect writing. believe that waveguides are regions concentration oxygen vacancies and/or their associated free electrons been altered by irradiation. not aware previous reports fluence being used influence vacancy related defects produce ceramics. This new mechanism opens door for writing strictures lower power than previously thought feasible.