A method for acquiring range data based on time-correlated single-photon counting is described. This method uses a short-pulse ( approximately 10-ps) laser diode, a detector based on a silicon single-photon avalanche diode, and standard photon-counting timing electronics. The accuracy of the technique has been measured as approximately +/-30 microm in a laboratory experiment and corresponds closely to the results of a theoretical simulation.

The design and implementation of a prototype time-of-flight optical ranging system based on the time-correlated single-photon-counting technique are described. The sensor is characterized in terms of its longitudinal and transverse spatial resolution, single-point measurement time, and long-term stability. The system has been operated at stand-off distances of 0.5-5 m, has a depth repeatability of <30 mum, and has a lateral spatial resolution of <500 mum.

The design and operation of a noncontact surface profilometry system based on the time-correlated single-photon-counting technique are described. This system has a robust optomechanical design and uses an eye-safe laser that makes it particularly suitable for operation in an uncontrolled industrial environment. The sensitivity of the photon-counting technique permits its use on a variety of target materials, and its mode of operation does not require the continual presence of an operator. The system described has been optimized for a 1-25-m standoff, has a distance repeatability of <30 microm, and has a transverse spatial resolution of approximately 60 microm at a 2-m standoff and approximately 400 microm at a 13-m standoff.

A commercially available germanium avalanche photodiode operating in the single-photon-counting mode has been used to perform time-resolved photoluminescence measurements on InGaAs/lnP multiple-quantum-well structures. Photoluminescence in the spectral region of 1.3-1.48 µm was detected with picosecond timing accuracy by use of the time-correlated single-photon counting technique. The carrier dynamics were monitored for excess photogenerated carrier densities in the range 10(18)-10(15) cm(-3). The recombination time is compared for similar InGaAs-based quantum-well structures grown by use of different epitaxial processes.

In this work the Preisach classical and nonlinear models are used to model the hysteretic response of a piezoceramic deformable mirror for use in adaptive optics. Experimental results show that both models predict the mirror behavior to within 5% root-mean-squared (rms) error. An inversion algorithm of the Preisach classical model for linearization of the mirror response was implemented and tested in an open-loop adaptive optics system using a Shack-Hartmann (SH) sensor. Measured errors were reduced from 20% rms to around 3%.