Connectorized Optical Link Package Incorporating a Microlens

An inexpensive connectorized optical data-link package for light-emitting diode (LED) sources, or p-i-n or avalanche photodiode (APD) photodetectors is described. This package uses a 1-mm diameter sapphire spherical lens to couple the light directly from the LED to the connectorized data-link fiber. For an LED with a 35-µm diameter light-emitting spat and a graded index, 0.23 numerical aperture (NA), 55-µm diameter core fiber, a coupling efficiency approximately equal to that for butt coupling is obtained. At the same time, the lateral and axial LED-fiber alignment tolerances are relaxed by factors of at least two and five, respectively. Preliminary thermal cycling measurements show no lass in coupled power after 230 cycles from -55°C to +150°C.