Picosecond laser ranging at wavelengths up to 2.4 μm using an InAs avalanche photodiode

Time-of-flight measurements using pulsed laser illumination in the wavelength region between 1.3 to 2.37 μm have been demonstrated with an InAs avalanche photodiode (APD). InAs is photo-sensitive at wavelengths up to 3.5 μm and with predominantly electron multipli- cation reducing detector noise, InAs APDs have clear potential for sen- sitive optical measurements of picosecond transients in the mid-wave infrared. Laboratory-based demonstrations of time-of-flight ranging using InAs APDs operated at room temperature is described.