We have improved the sensitivity and signal-to-noise ratio of a luminescence upconversion experiment, using a charge-coupled device (CCD) as the detector. We show experimentally and numerically that the bandwidth of a 1-mm-thick β-barium borate crystal is large enough to take full advantage of the multichannel capabilities of the CCD. The improvement is significant in a standard experiment with a single laser as well as in experiments with resonant excitation that use two synchronized femtosecond pulse sources at different wavelengths. The characteristics of the two-color scheme are discussed in detail.
© 1998 Optical Society of America
[Optical Society of America ]
S. Haacke, R. A. Taylor, I. Bar-Joseph, M. J. S. P. Brasil, M. Hartig, and B. Deveaud, "Improving the signal-to-noise ratio of femtosecond luminescence upconversion by multichannel detection," J. Opt. Soc. Am. B 15, 1410-1417 (1998)