Robust pigtail system for high power laser modules

摘要

In a high power, i.e. 100W and more, semiconductor laser module, used e.g. in opto-electronics as pump laser modules or in laser machining or medical applications, the laser power is launched into a glass fiber which transports the optical power to a desired location. It is difficult to focus the full laser power into the fiber core's end (8). Any misalignment results in stray energy heating up the fiber and its cladding, often resulting in catastrophic failure of the affected module. The invention concerns a robust and cost-effective design to manage and dissipate the heat generated by absorbing uncontrolled uncoupled and de-coupled stray light or radiation by providing a structure of a transparent ferrule (6) holding the fiber core (2) with its cladding (12), this ferrule (6) being fixed to a heat-dissipating component of the module by a transparent adhesive (20), whereby core (2), cladding (12), adhesive (20), and ferrule (6) each have a predetermined refractive index, chosen such that stray radiation is directed into the heat-dissipating component (5). A reflector (13) at the inner end of the ferrule (6), i.e. opposite the laser and preferably funnel-shaped, diverts any remaining stray radiation also towards the heat-dissipating component (5). This combination of features minimizes or avoids catastrophic damage such as melt-down or ignition.