Gow Paul C, Bannerman Rex H S, Mennea Paolo L, Holmes Christopher, Gates James C, Smith Peter G R
Opt Express. 2019 Sep 30;27(20):29133-29138. doi: 10.1364/OE.27.029133.
We present the first demonstration of integrated waveguides in planar silica devices fabricated using direct UV writing with 213 nm laser light. Waveguides were produced with different writing fluences and the NA and MFD of each were measured. Single mode waveguides were achieved at fluence values one-tenth that typically required when operating with a 244 nm laser, allowing for more rapid fabrication. A maximum in-plane index change of 2.4 ×10 for a writing fluence of 5 kJ cm was estimated from NA measurements. Finally cutback measurements were performed and a propagation loss of 0.42 ± 0.07 dB cm was directly measured, though losses as low as 0.2 ± 0.03 dB/cm are indicated through calculations.
我们展示了使用213 nm激光直接紫外写入制造的平面二氧化硅器件中集成波导的首次演示。通过不同的写入能量密度制作了波导，并测量了每个波导的数值孔径（NA）和模场直径（MFD）。在使用244 nm激光操作时，实现单模波导所需的能量密度值仅为通常所需值的十分之一，从而实现了更快的制造。根据NA测量估计，写入能量密度为5 kJ/cm²时，面内折射率最大变化为2.4×10⁻³。最后进行了截短测量，直接测量得到的传播损耗为0.42±0.07 dB/cm，不过通过计算表明损耗低至0.2±0.03 dB/cm。
