Nonlinear optical absorption of a new type of organo-metallic compound irradiated by nanosecond laser pulses

Nonlinear optical absorption of a new type of organometallic compound, [C₁₆r H₃₃ (CH₃)₃N] Ni(dmit)₂ (dmit^2- =4,5-dithiolate-1,3-dithiole -2-thione), abbreviated as CtNi, dissolved in acetone has been investigated by open-aperture Z-scan technique under irradiation with 1 ns and 15 ns laser pulses at 1053 nm. Strong saturable absorption is observed when the sample is irradiated by 1 ns laser pulses. While for 15 ns laser pulse width, the sample presents a stronger reverse saturable absorption. The coefficients of nonlinear optical absorption are β_SA = -1.79 × 10^-11 m/W and β _RSA = 4.53 × 10^-10 m/W, respectively. The mechanism responsible for the difference between the results is analyzed. All the results suggest that this material may be a promising candidate for the application to laser pulse compression in the near-infrared waveband. A graph is presented. OA Z-scan curves of CtNi sample solution illuminated by 1 ns and 15 ns laser pulse at 1053 nm. © 2007 by Astro Ltd.