The FDE851HLBF 850nm emitter features a hermetically sealed TO-can body with a glass optical window that helps protect the internal device from atmospheric conditions. The device boasts fast rise/fall times, enabling high-speed operation in the tens of MHz range, and contains integral micro-optics that focus the beam to a very narrow spot, providing efficient coupling to multimode glass optical fibers as small as 50 µm, achieving a typical launch power of 30 µW at 100 mA on 50/125 fiber.
Many fiber optic emitters use a clear plastic cap that presses onto the device head. While this provides a degree of physical protection for the LED chip, wire splicing, and internal optics, it is unusual for such a cap to provide a hermetic seal. This means that the potential long-term effects of environmental factors like humidity on the device's internal components must be considered in applications where extended lifespan is important. In contrast, the hermetically sealed housing of the FDE851HLBF eliminates this variable, as air from the operating environment cannot reach the internal components.
