Photoexcited Carrier Lifetime and Refractive Nonlinearity in Direct and Indirect Band Gap Crystals on the Z-Scan Technique
نویسندگان
چکیده مقاله:
The Photoexcited carrier lifetime (τ) and peak to valley transmission difference (ΔTp-v) in direct and indirect band gap crystals has been investigated by the use of single beam open and closed aperture z-scan technique using frequency doubled Nd:YAG laser. The peak to valley transmission difference (ΔTp-v) is found to be of the order of 10-2 in case of direct band gap crystals and of the order of 10-3 in case of indirect band gap crystals. The carrier life time (τ) is found to be in nanoseconds range in case of direct band gap crystals and picoseconds range in case of indirect band gap crystals. Lower value of (τ) and (ΔTp-v) in case of indirect band gap crystals can be attributed to the reduction in the value of carrier density (N) and small value of nonlinear phase shift ( Δϕ ),respectively.
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عنوان ژورنال
دوره 4 شماره None
صفحات 69- 76
تاریخ انتشار 2010-06
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