Bi8-M18-LF10 - Inductive sensor with frequency output, 1 ... 10 kHz, measuring range 1 ... 5 mm
SHIMPO SE-G2 - 0.04" (1 mm) sensing distance, square wave output, 8 kHz frequency
Si1120-A-GM - high-sensitivity active infrared proximity and ambient light sensor IC, typically 50 cm meter proximity range with single pulse, minimum reflectance sensitivity <1 μW/cm2, PWM output.