Flat Top Package: The HSDL-4400 Series of flat top IR emitters uses an untinted, non-diffused, truncated lens to provide a wide radiation pattern that is useful for short distance communication where alignment of the emitter and detector is not critical. The HSDL-5400 Series of flat top IR detectors uses the same truncated lens design as the HSDL-4400 Series of IR emitters with the added feature of a black tint that acts as an optical filter to reduce the effects of ambient light, such as sun, incandescent and fluorescent light from interfering with the IR signal. Dome Package: The HSDL-4420 Series of dome IR emitters uses an untinted, non-diffused lens to provide a 24 degree viewing angle with high on-axis intensity. The HSDL-5420 Series of IR detectors uses the same lens design as the HSDL-4420 IR emitter and optical filter used in the HSDL-5400 IR detector. Lead Configuration: All of these devices are made by encapsulating LED and PIN photodiode chips on axial lead frames to form molded epoxy sub miniature packages. A variety of lead configurations is available and includes: surface mount gull wing, yoke lead, or Z-bend and through hole lead bends at 2.54 mm (0.100 inch) center spacing. Technology: The sub miniature solid state emitters utilize a highly optimized LED material, transparent substrate aluminum gallium arsenide, TS AlGaAs. This material has a very high radiant efficiency, capable of producing high light output over a wide range of drive currents and temperature.