F. Wellmann
M. Steinke
P. Weßels
L. Overmeyer
J. Neumann
D. Kracht

CO2-laser based manufacturing of a few-mode all-fiber evanescent field coupler

Proceedings of the 9th EPS-QEOD Europhoton virtual conference
Type: Zeitschriftenaufsatz (non-reviewed)
We present a CO2-laser based micro-machining process to manufacture all-fiber mode-selective couplers. A CO2-laser beam is used to perform multiple steps of the manufacturing chain. The first step is the removal of the fiber’s polymer coating. This is followed by a lateral removal of large parts of the fiber’s glass cladding to access the evanescent field of the light guided within the core. Excellent surface quality and process control for precision cladding removal are demonstrated. Thus, enabling the manufacturing of fiber components and the usage in evanescent field based sensor applications. Mode-selective coupling between two fiber cores is achieved by fusing two altered fibers together and overlapping their mode fields. Component excess loss of 0.13 dB is demonstrated. Experimental results are compared with simulation results and show good agreement.