Brusberg Lars, Whalley Simon, Herbst Christian, Schröder Henning
Opt Express. 2015 Dec 14;23(25):32528-40. doi: 10.1364/OE.23.032528.
Parallel optical interconnects on-board level requires low propagation loss in wavelength range between 850 and 1550 nm to be compatible with datacom and telecom optical engines. For highest integration density tight waveguide bends and a scalable number of optical layers should be manufacturable for 2D interfaces to optical fiber array connectors and photonic assembly I/O's. We developed a glass waveguide panel process for double-sided processing of commercial available display glass by applying a two-step thermal ion-exchange process for low-loss multi-mode graded-index waveguides. Multiple glass waveguide panels can be embedded between electrical layers. The generic concept enables fabrication of high-density integration (HDI) electro-optical circuit boards (EOCB) with high number of optical and electrical layers. Waveguides with high NA of 0.3 for low bend losses could be achieved in glass with propagation loss of 0.05 dB/cm for all key wavelengths. Four of those glass waveguide panels were embedded in an EOCB demonstrator with size of 280 x 233 mm² providing eight optical layers with 96 channels in an area of 2.8 x 1.5 mm². To the best of our knowledge it's the highest number of layers that has ever been demonstrated for an EOCB.
板级并行光互连要求在850至1550纳米波长范围内具有低传播损耗，以便与数据通信和电信光引擎兼容。为了实现最高的集成密度，对于与光纤阵列连接器和光子组件I/O的二维接口，应能够制造紧密的波导弯曲和可扩展数量的光学层。我们通过应用两步热离子交换工艺来制造低损耗多模渐变折射率波导，开发了一种用于商用显示玻璃双面加工的玻璃波导面板工艺。多个玻璃波导面板可以嵌入电气层之间。这种通用概念能够制造具有大量光学和电气层的高密度集成（HDI）电光电路板（EOCB）。对于所有关键波长，在传播损耗为0.05 dB/cm的玻璃中，可以实现具有0.3高数值孔径（NA）的低弯曲损耗波导。其中四个玻璃波导面板被嵌入到一个尺寸为280 x 233 mm²的EOCB演示器中，在2.8 x 1.5 mm²的区域内提供八个光学层和96个通道。据我们所知，这是EOCB有史以来展示的最高层数。
