SILICON V-GROOVE ALIGNMENT BENCH FOR OPTICAL COMPONENT ASSEMBLY
Author: Terry Bowen Company: TE Connectivity Date Published: 1/22/2013
Pan Pacific Symposium
Abstract: One of the primary technical challenges associated with the manufacture of optical assemblies, especially systems with higher levels of integration, is component to component optical alignment. Components must be brought into precise spatial relationship and the precision of this alignment must be captured and maintained throughout the useful lifetime of the assembly. The alignment step can be done actively or passively. The active approach is more complicated involving powering up devices and measuring optical coupling results while moving the components into the aligned position. The passive approach relies on building precision into the parts so that they can be directly assembled into the aligned position without activating the components. This paper describes the use of a large V-groove wet etched into a silicon wafer to form an alignment bench component, which can be used in combinations with silicon based interposer / photonic integrated circuit (PIC) die and either additional similar die, or optical fibers assembled with cylindrical ferrules such as the LC connector ferrule. The silicon interposer die / PIC die are constructed with wet etched v-grooves along the locations where the die will be diced. This allows the sidewalls of these edge locator grooves to be used in combination with the alignment bench to precisely position features on the die relative to other similarly constructed components or optical fibers. The accuracy achieved by the photolithographic processes employed allow passive alignment to be used for constructing these assemblies.