| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
1 We tasted a dye laser synchronously pumped by the third harmonic pulses (output power of 5OO-6OOmW) of a mode-locked cw ND-YAG laser (Antares 76s, output power of 25W). By using Stilbene 3 dye, we obtained pulses with 100- I 5OmW output power in the wavelength range from 4 10 to 460 nm. We also tried to shorten the pulses by insertingsaturableabsorberinthedyelaser. Temporalwidthofthepulsesarefoundtobel-1.4pswhichare measured by 2nd harmonic-generafion autocorrelation method using high fidelity, rapid-scanning Kfichelson interferometer equipped with BBO crystal. By using NK557 (Nihon Kanko Shildso) or Coumarin 7, pulses with the width less than lps with the output power reduced to about 1/3 are obtained. It was found, however, that not only the long-time stability is worse but also pulse-to-pulse intensity fluctuation as well as spatial fluctuafion of the pulses is not negligibly small.
2 We constructed high fidelity, rapid-scanning-Nfichelson interferometer. This interferometer has enough precision that enable us to measure interference pattem between the two laser beams, which is confirmed by the test using femtosecond laser pulses from Ar ion laser pumped Rhodamine 6G dye laser.
3 We also tried to measure autocorrelation traces by luminescence correlation method. Swuples used are molecular beam epitaxially-grown ZnSe and bulk CdS crystals. In each samples, we confirmed that the luminescence autocorrelation traces show the similar shape as 2nd harmonic generation autocorrelation traces. However, the results are not so accurate to compare between those two and to discuss in detail, because of the inferior stability of the laser pulses. Wecansaythattheluminescencecoffelationmethod, atleast, givesthemeasureofthepulsewidth, andthus can be applied to the measurements in the short-wavelength range where nonlinear crystals such as BBO can not be used.
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