The EL0500, EL0501, EL0452 and EL0453 devices each consist of an infrared emitting diode, optically coupled to a high speed photo detector transistor. A separate connection for the photodiode bias and output-transistor collector increase the speed by several orders of magnitude over conventional phototransistor couplers by reducing the base-collector capacitance of the input transistor. The EL0600, EL0601 and EL0611 devices each consists of an infrared emitting diode optically coupled to a high speed integrated photo detector logic gate with a strobable output. The devices are packaged in an 8-pin small outline package which conforms to the standard SO-8 footprint.