The HFE4090-321 is a high-performance 850 nm VCSEL (Vertical Cavity Surface-Emitting Laser) packaged for high-speed data communications.
The HFE4090-321 is a high radiance VCSEL designed to convert electrical current into optical power that can be used in fiber optic communications and other applications. As the current varies above threshold, the light intensity increases proportionally.
The HFE4090-321 is designed to be used with inexpensive silicon or gallium arsenide detectors, but excellent performance can also be achieved with some indium gallium arsenide detectors.
The low drive current requirement makes direct drive from PECL (Positive Emitter Coupled Logic) or EML (Emitter Coupled Logic) gates possible and eases driver design.
The HFE4090-321 is designed to interface with 50/125 and 62.5/125 µm multimode fiber. It produces circularly symmetric, non-astigmatic, narrow divergence beams that, with appropriate lensing, fiber couple all of the emitter power.

FEATURES
• Designed for drive currents
   between 5 and 15 mA
• Optimized for low dependence
   of electrical properties over
   temperature
• High speed ≥1 GHz