India Ink/Carbon Disulfide Creates Laser Safety Device

The use of carbon disulfide and dilute India ink for optical sensors to protect the human eye from high-power coherent light was discussed. The optical limiters developed exhibited superior performance due to a combination of two nonlinear materials in a cascaded-focus geometry. The limiter exhibited strong scattering created by laser-induced breakdown and plasma generation limiting the transmittance

Broadband Optical Limiter Using Carbon-Black Suspensions In Cs2

A report on the braodband optical limiter using carbon-black suspensions (CBS) in carbon disulfide was presented. The CBS were tested in the cascaded optical limiter at several wavelengths across the visible to determine the wavelength dependence of the CBS. The laser source used was a nanosecond optical parametric oscillator producing pulses of 3-4 ns duration

Excited-State Absorption And Anisotropy Properties Of Two-Photon Absorbing Fluorene Derivatives

The electronic structure of fluorene derivatives N-(7-benzothiazol-2-yl-9,9-bis-decyl-9H-fluoren-2-yl)-acetamide (1); 9,9-didecyl-2,7-bis-(N,N-benzothiazoyl)fluorene (2); 4,4′-{[9,9-bis(ethyl)-9H-fluorene-2,7-diyl]di-2,1-ethenediyl}bis(N, N-diphenyl)benzeneamine(3); and4,4′,4″([9,9-bis(ethyl)-9H-fluorene-2,4,7-triyl]tri-2, 1-ethenediyl}tris(N,N-diphenyl)benzeneamine (4) were investigated by a steady-state spectral technique, quantum-chemical calculations, and a picosecond pump-probe method. These derivatives are of interest for their relatively high two-photon absorption. The steady-state excitation anisotropy spectra reveal the nature of the ground-state absorption bands. Semiempirical quantum-chemical calculations of the fluorene derivatives (AMI, ZINDO/S) show good agreement with experimental data. The spectral positions and alignment of various electronic transitions of derivatives 1-4 were estimated from their excited-state absorption and anisotropy spectra. © 2005 Optical Society of America