Embedded Micromirror Inserts for Optical Printed Circuit Boards

We present the use of an embedded 45$^{\circ}$ micromirror, which is patterned in polymer photoresist using deep proton writing. The micromirror is metallized and inserted in a laser ablated cavity in the optical layer and in a next step covered with cladding material. Surface roughness measurements confirm the excellent quality of the mirror facet. Loss measurements have been carried out to evaluate the behavior of the embedded micromirror. These measurements indicate an average loss below 0.35 dB, measured in a receiver scheme, which is the most stringent configuration.