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You searched for +publisher:"University of North Texas" +contributor:("Soileau, M. J."). Showing records 1 – 3 of 3 total matches.

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University of North Texas

1. Wu, Yuan-Yen. Optical Nonlinearities in Semiconductors for Limiting.

Degree: 1990, University of North Texas

I have conducted detailed experimental and theoretical studies of the nonlinear optical properties of semiconductor materials useful for optical limiting. I have constructed optical limiters utilizing two-photon absorption along with photogenerated carrier defocusing as well as the bound electronic nonlinearity using the semiconducting material ZnSe. I have optimized the focusing geometry to achieve a large dynamic range while maintaining a low limiting energy for the device. The ZnSe monolithic optical limiter has achieved a limiting energy as low as 13 nJ (corresponding to 300W peak power) and a dynamic range as large as 105 at 532 nm using psec pulses. Theoretical analysis showed that the ZnSe device has a broad-band response covering the wavelength range from 550 nm to 800 nm. Moreover, I found that existing theoretical models (e.g. the Auston model and the band-resonant model using Boltzmann statistics) adequately describe the photo-generated carriers refractive nonlinearity in ZnSe. Material nonlinear optical parameters, such as the two-photon absorption coefficient β2=5.5cm/GW, the refraction per unit carrier density σn=-0.8∗10-21cm3 and the bound electronic refraction n2=-4∗10-11esu, have been measured via time-integrated beam distortion experiments in the near field. A numerical code has been written to simulate the beam distortion in order to extract the previously mentioned material parameters. In addition, I have performed time-resolved distortion measurements that provide an intuitive picture of the carrier generation process via two-photon absorption. I also characterized the optical nonlinearities in a ZnSe Fabry-Perot thin film structure (an interference filter). I concluded that the nonlinear absorption alone in the thin film is insufficient to build an effective optical limiter, as it did not show a net change in refraction using psec pulses. An innovative numerical program was developed to simulate the nonlinear beam propagation inside the Fabry-Perot structure. For comparison, pump-probe experiments were performed using both thin film and bulk ZnSe. The results showed relatively long carrier lifetimes (>300 psec) in both samples. A numerical code was written to fit the pump-probe experimental results. The fitting yielded that carrier lifetimes (recombination through traps), radiative decay rate, two-photon absorption coefficient as well as the free carrier absorption coefficient for ZnSe bulk material. Advisors/Committee Members: Van Stryland, Eric W., Soileau, M. J., West, Bruce J., Duggan, Jerome L., Kobe, Donald Holm.

Subjects/Keywords: semiconductors; optical limiting; absorptive nonlinearity; refractive nonlinearity; nonlinear material; Semiconductors  – Optical properties.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wu, Y. (1990). Optical Nonlinearities in Semiconductors for Limiting. (Thesis). University of North Texas. Retrieved from https://digital.library.unt.edu/ark:/67531/metadc331203/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Wu, Yuan-Yen. “Optical Nonlinearities in Semiconductors for Limiting.” 1990. Thesis, University of North Texas. Accessed October 28, 2020. https://digital.library.unt.edu/ark:/67531/metadc331203/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Wu, Yuan-Yen. “Optical Nonlinearities in Semiconductors for Limiting.” 1990. Web. 28 Oct 2020.

Vancouver:

Wu Y. Optical Nonlinearities in Semiconductors for Limiting. [Internet] [Thesis]. University of North Texas; 1990. [cited 2020 Oct 28]. Available from: https://digital.library.unt.edu/ark:/67531/metadc331203/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wu Y. Optical Nonlinearities in Semiconductors for Limiting. [Thesis]. University of North Texas; 1990. Available from: https://digital.library.unt.edu/ark:/67531/metadc331203/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of North Texas

2. Mansour, Nastaran. Nonlinear Absorption Initiated Laser-Induced Damage in [Gamma]-Irradiated Fused Silica, Fluorozirconate Glass and Cubic Zirconia.

Degree: 1988, University of North Texas

The contributions of nonlinear absorption processes to laser-induced damage of three selected groups of transparent dielectrics were investigated. The studied materials were irradiated and non-irradiated fused silica, doped and undoped fluorozirconate glass and cubic zirconia stabilized with yttria. The laser-induced damage thresholds, prebreakdown transmission, and nonlinear absorption processes were studied for several specimens of each group. Experimental measurements were performed at wavelengths of 1064 nm and 532 nm using nanosecond and picosecond Nd:YAG laser pulses. In the irradiated fused silica and fluorozirconate glasses, we found that there is a correlation between the damage thresholds at wavelength λ and the linear absorption of the studied specimens at λ/2. In other words, the laser-induced breakdown is related to the probability of all possible two-photon transitions. The results are found to be in excellent agreement with a proposed two-photon-initiated electron avalanche breakdown model. In this model, the initial "seed" electrons for the formation of an avalanche are produced by two-photon excitations of E' centers and metallic impurity levels which are located within the bandgaps of irradiated Si02 and fluorozirconate glasses, respectively. Once the initial electrons are liberated in the conduction band, a highly absorbing plasma is formed by avalanche impact ionization. The resultant heating causes optical damage. In cubic zirconia, we present direct experimental evidence that significant energy is deposited in the samples at wavelength 532 nm prior to electron avalanche formation. The mechanism is found to be due to formation of color centers (F+ or F° centers) by the two-photon absorption process. The presence of these centers was directly shown by transmission measurements. The two-photon absorption (2PA) process was independently investigated and 2PA coefficients obtained. The accumulated effects of the induced centers on the nonlinear absorption measurements were also considered and the 2PA coefficients were measured using short pulses where this effect is negligible. At room temperature, the color centers slowly diffuse out of the irradiated region. The density of these centers was monitored as a function of time. The initial distribution of the centers was assumed to have a Gaussian profile. For this model the diffusion equation was solved exactly and the diffusion constant obtained. Advisors/Committee Members: Van Stryland, Eric W., Soileau, M. J., Deering, William D., Mackey, H. J., Smirl, Arthur L..

Subjects/Keywords: nonlinear absorption; fluorozirconate glass; cubic zirconia; γ-irradiated fused silica; laser-induced damage; Optical materials  – Defects.; Optical materials  – Effect of radiation on.; Lasers in physics.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Mansour, N. (1988). Nonlinear Absorption Initiated Laser-Induced Damage in [Gamma]-Irradiated Fused Silica, Fluorozirconate Glass and Cubic Zirconia. (Thesis). University of North Texas. Retrieved from https://digital.library.unt.edu/ark:/67531/metadc331327/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Mansour, Nastaran. “Nonlinear Absorption Initiated Laser-Induced Damage in [Gamma]-Irradiated Fused Silica, Fluorozirconate Glass and Cubic Zirconia.” 1988. Thesis, University of North Texas. Accessed October 28, 2020. https://digital.library.unt.edu/ark:/67531/metadc331327/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Mansour, Nastaran. “Nonlinear Absorption Initiated Laser-Induced Damage in [Gamma]-Irradiated Fused Silica, Fluorozirconate Glass and Cubic Zirconia.” 1988. Web. 28 Oct 2020.

Vancouver:

Mansour N. Nonlinear Absorption Initiated Laser-Induced Damage in [Gamma]-Irradiated Fused Silica, Fluorozirconate Glass and Cubic Zirconia. [Internet] [Thesis]. University of North Texas; 1988. [cited 2020 Oct 28]. Available from: https://digital.library.unt.edu/ark:/67531/metadc331327/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mansour N. Nonlinear Absorption Initiated Laser-Induced Damage in [Gamma]-Irradiated Fused Silica, Fluorozirconate Glass and Cubic Zirconia. [Thesis]. University of North Texas; 1988. Available from: https://digital.library.unt.edu/ark:/67531/metadc331327/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of North Texas

3. Wei, Tai-Huei. Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes.

Degree: 1992, University of North Texas

This dissertation deals with the characterization of the nonlinear absorption and refraction of two representative metallophthalocyanine dyes: chloro aluminum phthalocyanine dissolved in methanol, referred to as CAP, and a silicon naphthalocyanine derivative dissolved in toluene, referred to as SiNc. Using the Z-scan technique, the experiments are performed on both the picosecond and nanosecond timescales at a wavelength of 0.532 μm. Advisors/Committee Members: Van Stryland, Eric W., Soileau, M. J., Deering, William D., Theriot, L. J., Mackey, H. J., West, Bruce J..

Subjects/Keywords: nonlinear optical absorption; refraction; metallophthalocyanine dyes; Light absorption.; Refraction.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wei, T. (1992). Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes. (Thesis). University of North Texas. Retrieved from https://digital.library.unt.edu/ark:/67531/metadc278287/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Wei, Tai-Huei. “Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes.” 1992. Thesis, University of North Texas. Accessed October 28, 2020. https://digital.library.unt.edu/ark:/67531/metadc278287/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Wei, Tai-Huei. “Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes.” 1992. Web. 28 Oct 2020.

Vancouver:

Wei T. Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes. [Internet] [Thesis]. University of North Texas; 1992. [cited 2020 Oct 28]. Available from: https://digital.library.unt.edu/ark:/67531/metadc278287/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wei T. Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes. [Thesis]. University of North Texas; 1992. Available from: https://digital.library.unt.edu/ark:/67531/metadc278287/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.