We demonstrate a source of photon pairs with widely separated wavelengths, 810 and 1548 nm, generated through spontaneous four-wave mixing in a microstructured fiber. The second-order autocorrelation function g((2))(0) was measured to confirm the nonclassical nature of a heralded single-photon source constructed from the fiber. The microstructured fiber presented herein has the interesting property of generating photon pairs with wavelengths suitable for a quantum repeater able to link free-space channels with fiber channels, as well as for a high-quality telecommunication wavelength heralded single photon source. It also has the advantage of potentially low-loss coupling into standard optical fiber. These reasons make this photon pair source particularly interesting for long-distance quantum communication.

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Possible causes of the spatial distortion encountered when using pierced resistive anodes for position-sensitive detection are discussed. An accurate map of the spatial distortion around a circular hole in a resistive anode is presented, which shows that the hole's effect is felt at distances up to three times its radius. The effect of load conditions on the detector's spatial linearity, as well as the distortions induced near the center of the detector due to penetrating electrostatic fields, are also discussed. In response to these points, alternative methods are described-in hardware and software-for the correction of distorted images. The hardware approach, which makes use of electrically programmable readonly memories, has the advantage of allowing real-time operation albeit with some loss in the precision of the intensities of the features within an image. One benefit of the software approach, beside the fact that it provides the best possible correction of the intensities, lies in the fact that all the information contained in the raw data is kept intact, which gives some latitude for future recalibration of the detector, or for emulation of a detector of another shape.