Showing papers by "Richard DeSalvo published in 1992"
TL;DR: This work monitors the induced phase change produced by a cascaded chi((2)):chi((2)) process in KTP near the phase-matching angle on a picosecond 1.06-microm-wavelength beam using the Z-scan technique and predicts the maximum small-signal effective nonlinear refractive index.
Abstract: We monitor the induced phase change produced by a cascaded χ(2):χ(2) process in KTP near the phase-matching angle on a picosecond 1.06-μm-wavelength beam using the Z-scan technique. This nonlinear refraction is observed to change sign as the crystal is rotated through the phase-match angle in accordance with theory. This theory predicts the maximum small-signal effective nonlinear refractive index of n2eff≅±2×10−14 cm2/W (±1 × 10−11 esu) for an angle detuning of ±5° from phase match for this 1-mm-thick crystal with a measured deff of 3.1 pm/V For a fixed phase mismatch, this n2eff scales linearly with length and as deff2; however, for the maximum n2eff the nonlinear phase distortion becomes sublinear with irradiance for phase shifts near π/4.
614 citations
TL;DR: A simple dual-wavelength (two-color) Z-scan geometry is demonstrated for measuring nonlinearities at frequency omega(p) owing to the presence of light at omega(e) and this technique gives the nondegenerate two-photon absorption (2PA) coefficient beta(omega(p); omega( e) and the nondEGenerate nonlinear refractive index n(2) i.e., cross-phase modulation.
Abstract: A simple dual-wavelength (two-color) Z-scan geometry is demonstrated for measuring nonlinearities at frequency ωp owing to the presence of light at ωe. This technique gives the nondegenerate two-photon absorption (2PA) coefficient β(ωp; ωe) and the nondegenerate nonlinear refractive index n2(ωp; ωe), i.e., cross-phase modulation. We demonstrate this technique on CS2 for n2 and on ZnSe where 2PA and n2 are present simultaneously.
199 citations
TL;DR: In this paper, an increase in the dynamic range of an optical limiting device is achieved by using two different nonlinear elements cascaded within a single limiting device, and a comparison between the results of optical limiting experiments for a single nonlinear element limiter and a two-element limiter shows a significant increase in damage threshold of the latter with only a small increase of the limiting threshold.
Abstract: An increase in the dynamic range of an optical limiting device is achieved by using two different nonlinear elements cascaded within a single limiting device. A comparison between the results of optical limiting experiments for a single nonlinear element limiter and a two element limiter shows a significant increase in the damage threshold of the latter with only a small increase of the limiting threshold.
11 citations
29 Jul 1992
TL;DR: In this paper, the nonlinear refractive coefficient n2 in BaF2, LiF, MgF 2, Al2O3 and diamond using the Z-scan technique at (lambda) equals 1.06, 0.532, and 0.355 micrometers.
Abstract: We measure the nonlinear refractive coefficient n2 in BaF2, LiF, MgF2, Al2O3 and diamond using the Z-scan technique at (lambda) equals 1.06, 0.532, and 0.355 micrometers . Two-photon absorption in diamond at 0.355 micrometers is also measured. The results are in good agreement with a two-parabolic band theory developed for semiconductors.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
6 citations
TL;DR: In this article, it has been shown that second-order nonlinear interactions lead to effective third order nonlinearities and nonlinear phase shifts in the funda-mental beam.
Abstract: A continuing problem in nonlinear optics has been to f ind third order materials w i th large, fast nonlinearities in spec tral regions of low linear and nonlinear absorption. Typica l applications of such materials require large nonlinear phase shifts. It has been known, but not wide ly appreciated, that second order nonlinear interactions lead to effective third order nonlinearities and nonlinear phase shifts i n the funda mental beam. Whi le such phenomena are impl ic i t ly included in the standard equations governing, for example, secondharmonic generation (SHG) and have been theoretically pre dicted previously, 1 only recently has the phase distort ion been studied i n detail experimentally and theoretically. 2 , 3