B. D. Lucas

Norfolk State University, Norfolk, Virginia, United States

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Publications (15)17.42 Total impact

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    ABSTRACT: Using a z-scan technique, we have shown that in Mn:YAlO3 the nonlocal component of the photorefractive response is greater than the local contribution. Although the strongest photorefractive response measured by the z-scan technique was found at light polarization E parallel to the crystallographic axis b (E||b), the highest holographic diffraction efficiency was obtained at E||c. The observed seeming discrepancy between the z-scan results and the holographic diffraction-efficiency results is explained by polarization-dependent photoinduced absorption: This absorption has the smallest intensity and the smallest effect on the holographic diffraction efficiency at E||c.
    Journal of the Optical Society of America B 06/2003; 20(6). DOI:10.1364/JOSAB.20.001233 · 1.81 Impact Factor
  • M. Vondrova, B. D. Lucas, M. A. Noginov
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    ABSTRACT: The transient dynamics and the kinetics of switching between two stable states in Cr:LiSrGaF6 laser crystal, a material with thermally induced intrinsic optical bistability, have been studied. It has been shown that the characteristic switching time τswitch can be shorter than that determined by the heat transfer in a linear regime. In the quasi-steady-state regime, the rate of switching (τswitch-1) in the system studied is proportional to the square root of the area of the steady-state hysteresis loop. The switching time τswitch can be controlled by changing system parameters, such as the temperature of the heat sink, the heat sinking efficiency, the rate of the pumping power increase, etc. When the pumping power is continuously changed at the rate R, the increment in the switching rate Δτswitch-1 is proportional to R2/3.
    Journal of the Optical Society of America B 01/2003; 20(6). DOI:10.1364/JOSAB.20.001295 · 1.81 Impact Factor
  • M. A. Noginov, B. D. Lucas, M. Vondrova
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    ABSTRACT: We theoretically predict and experimentally demonstrate the effect of optical bistability in a Cr:LiSrGaF6 laser, where one of its parameters (emission quantum yield) has a strongly nonlinear dependence on temperature. The effects of various experimental parameters on optical bistability and the size of the hysteresis loop are theoretically studied. The theoretical and experimental results are in good agreement with each other.
    Journal of the Optical Society of America B 09/2002; 19(9):1999-2006. DOI:10.1364/JOSAB.19.001999 · 1.81 Impact Factor
  • Advanced Solid State Lasers; 02/2002
  • MA Noginov, M. Vondrova, B. D. Lucas
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    ABSTRACT: We have shown that a very strong nonlinearity in the temperature dependence of the luminescence quantum yield in Cr-doped laser crystals of the Colquiriite family can lead to a temperature induced intrinsic optical bistability in these materials. The bistability and the hysteresis loop in the dependence of Cr luminescence intensity and transmission of the crystal on cw pumping power has been theoretically predicted and experimentally observed. The experimental results are in a good qualitative and quantitative agreement with the theoretical prediction.
    Physical Review B 01/2002; 65(3):35112-. DOI:10.1103/PhysRevB.65.035112 · 3.74 Impact Factor
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    ABSTRACT: We propose and experimentally realize the recording of two-color holographic gratings in Mn:YAlO(3), a potential material for holographic data storage. This type of recording allows for nonvolatile retrieval of recorded information at the recording wavelength. We demonstrate two-color recording and readout of a 256 x 256 pixel page using red and green laser beams with a bit error rate of 6 x 10(-7).
    Applied Optics 09/2001; 40(23):3915-21. DOI:10.1364/AO.40.003915 · 1.78 Impact Factor
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    ABSTRACT: We have grown neodymium-doped mixed apatite crystals [(Sr<sub>1-x </sub>Ba<sub>x</sub>)<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>F, Sr<sub>5 </sub>(P<sub>1-x</sub>V<sub>x</sub>O<sub>4</sub>)<sub>3</sub>F, and Ba <sub>5</sub>(P<sub>1-x</sub>V<sub>x</sub>O<sub>4</sub>)<sub>3</sub>F] and spectroscopically studied them as potential gain media for a laser source for atmospheric water sensing operating at 944.11 nm. We conclude that an appropriate apatite host material for a 944.11 nm laser should be a mixture of Sr<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>F. With a small fraction of Ba<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>F. Precise wavelength tuning around 944.11 nm can be accomplished by varying the host composition, temperature, and threshold population inversion. In apatite crystals of mixed composition, the amplified spontaneous emission (ASE) loss at 1.06 μm is predicted to be significantly smaller than that in the end members
    IEEE Journal of Quantum Electronics 04/2001; DOI:10.1109/3.910459 · 2.11 Impact Factor
  • M.A. Noginov, M. Vondrova, B.D. Lucas
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    ABSTRACT: Summary form only given. An intrinsic optical bistability can find potential applications in optical logic elements and switches for optical computing, telecommunication, etc. The effect can be predicted in many different systems with various physical mechanisms of nonlinearity. The bistability derived as a consequence of modification of the optical Bloch equations after introducing the local field correction terms, was first experimentally observed in Yb<sup>3+</sup>:Cs<sub>3</sub> Y<sub>2</sub>Br<sub>9</sub>. We theoretically predict and experimentally demonstrate an intrinsic bistability in luminescence and transmission of Cr doped LiSrGaF<sub>6</sub> (LiSGaF) and LiSrAlF<sub>6</sub> (LiSAF) crystals, in which the luminescence quantum yield has a strongly nonlinear dependence on temperature T.
    Quantum Electronics and Laser Science Conference, 2001. Technical Digest. Summaries of Papers Presented at the; 02/2001
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    ABSTRACT: © 2001 Optical Society of America
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    ABSTRACT: We have studied the processes of photocoloration and discoloration in Mn:YAlO and relevant crystals. We show the following: (1) The coloration rate in Mn:YAlO does not depend on Mn concentration. (2) The effective recombination time of free electrons with Mn{sup 5+} ions and deep traps is of the order of 0.5 ms. (3) The rate of photocoloration increases with an increase in temperature. (4) The discoloration kinetics in Mn:YAlO are strongly nonexponential. At room temperature the effective discoloration time approximates 120 years. (5) At increased temperatures the discoloration kinetics accelerate dramatically. (6) We have grown and characterized Mn:GdAlO and Mn:YbAlO crystals. The activation energy in these crystals is much larger than that in Mn:YAlO. This suggests the great potential of MnYbAlO and Mn:GdAlO in terms of permanent data storage.
    Journal of the Optical Society of America B 01/2001; 18(7):931-941. DOI:10.1364/JOSAB.18.000931 · 1.81 Impact Factor
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    ABSTRACT: We have grown neodymium doped mixed apatite crystals, (SrxBa1- x)5(PO4)3F, Sr5(P1-xVxO4)3F, and Ba5(P1-xVxO4)3F, and spectroscopically studied them as potential gain media for a laser source for atmospheric water sensing operating at 944.11 nm. We conclude that an appropriate apatite host material for a 944.11 nm laser should be a mixture of Sr5(PO4)3F with a small fraction of Ba5(PO4)3F. The precise wavelength tuning around 944.11 nm can be accomplished by varying the host composition, temperature, and threshold population inversion. In apatite crystals of mixed composition, the amplified spontaneous emission loss at 1.06 micrometers is predicted to be significantly smaller than that in the end members.
    Proceedings of SPIE - The International Society for Optical Engineering 04/2000; DOI:10.1117/12.382788 · 0.20 Impact Factor
  • Source
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    ABSTRACT: Summary form only given. Holographic gratings with high diffraction efficiency (>50%) can be recorded in YAlO<sub>3</sub>:Mn with green or blue laser beams. The storage time extrapolated to room temperature is much greater than ten years. Gratings can be erased by heating the crystal to about 270°C. These properties in combination with the high optical quality of the crystal give promise to this material for use in holographic data storage
    Lasers and Electro-Optics, 2000. (CLEO 2000). Conference on; 02/2000
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    ABSTRACT: In search for intrinsic optical bistability in solid-state optical materials, we studied cooperative absorption and emission in Yb<sub>3 </sub>Al<sub>3</sub>O<sub>12</sub>, Yb<sub>2</sub>O<sub>3</sub>, Yb:Y <sub>2</sub>O<sub>3</sub>, Yb:Lu<sub>2</sub>O<sub>3</sub> and Yb:Sc<sub>2</sub>O<sub>3</sub> laser related crystals. The bistability in cooperative luminescence in Yb(6%):Sc<sub>2</sub>O<sub>3</sub> has been observed
    Nonlinear Optics: Materials, Fundamentals, and Applications, 2000. Technical Digest; 02/2000
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    ABSTRACT: In search for intrinsic optical bistability in solid-state optical materials, we studied cooperative absorption and emission in Yb : Y3Al5O12, Yb3Al5O12, Yb : Sc2O3, Yb:Y2O3, and Yb2O3 laser related crystals. The bistability in cooperative luminescence in Yb(6%) : Sc2O3 has been observed.
    Journal of Luminescence 01/2000; 96(2-4-96):129-140. DOI:10.1016/S0022-2313(01)00210-1 · 2.37 Impact Factor
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    ABSTRACT: In search for novel photonic materials, we have grown and characterized manganese doped CaYAlO4 crystals. This material is relevant to Mn:YaIO3, a promising material for holographic data storage. Luminescence of Mn ions can make this material potentially interesting for tunable laser applications. Additionally, spectroscopic studies of Mn ions in this crystal may help in understanding properties of colossal magneto-resistance materials. In this work, using the Czochralski technique, we have grown several manganese doped CaYAlO4 crystals and characterized their optical absorption, emission, and EPR properties
    Filtration Industry Analyst 01/2000; DOI:10.1109/CLEO.2000.907155