Tapered fused bundle coupler package for reliable high optical power dissipation

摘要

Light absorption in structural adhesives constitutes the main source of heat in tapered fused bundle (TFB) devices. Efficient heat dissipation solutions were developed by studying these thermal loads. The relative merits of transparent vs. opaque package designs were established experimentally. In the former, light escapes without being absorbed by the package walls, whereas in the latter, the spurious optical signal is directly absorbed and dissipated. The fact that heat is generated directly in the adhesive largely favors the opaque package, which offers more efficient heat extraction. By using a thermally conductive package, a temperature rise of 1.1 ℃ per Watt of dissipated power was measured. These numbers demonstrate that passive heat sinking at 20℃ is sufficient to allow reliable operation up to 45Watts of dissipated power (1kW with 0.2dB optical loss) without compromising long-term reliability.