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For the last decade, Dr. Genack has been involved in the study of classical wave propagation in the presence of disorder. Classical waves are the means by which we probe our environment and communicate with one another. As a result of wave - particle duality, studies of classical waves also serve as exacting models of electronic transport, involving quantum mechanical waves, in the solid state. One goal of studies at Queens College of optical and microwave radiation propagation is to provide a universal description of wave scattering in random systems. The Queens College group has demonstrated the relationship between the statistics of fluctuations of intensity and total transmission, non-local intensity correlation, and average transport in space, time, and frequency. This has provided essential models of electronic transport in mesoscopic systems, which are systems in which the phase coherence of the wave is preserved throughout the sample. Essential aspects of transport are described in terms of the degree of intensity correlation in space, which determines the closeness to the threshold for Anderson localization. Beyond the localization threshold, propagation is largely suppressed as a result of the interference of backscattered waves. The microwave laboratory was started in collaboration with Dr. Narciso Garcia. Many key measurements have been compared to theoretical calculations of Dr. A. A. Lisyansky and his students.
Among the milestones achieved in statistical studies have been the following: observations of short, long and infinite range intensity correlation in space and frequency; observation of the consequences of such correlation in producing marked and universal deviations of intensity and transmission distributions from their form for diffusive waves far from the localization threshold; observation of universal dynamical fluctuations in the dwell time of waves in random media; measurements of the statistical character of the transmitted field in the crossover from ballistic to diffusive propagation; creation of localized states in nearly periodic copper wire network filled with random mixtures of scattering particles; observations of resonances and in random media; and the inclusion of boundary effects to quantitatively describe transport. In addition acousto-optic tomography using diffuse light has been demonstrated, and Monte Carlo simulations of the random walk of photons in amplifying random media have established the incoherent nature of laser action in these systems.
In work carried out before coming to Queens College, Dr. Genack has demonstrated the diffusion of nuclear magnetism in superconductors, measured the spectrum of Wannier excitons in Cu2O, demonstrated the use of photochemical hole burning to measure the homogeneous linewidth of molecules in solids, developed methods of coherent transient spectroscopy such as frequency and phase switching which have clarified the loss of coherence in atoms, molecules and solids, and has demonstrated that the origin of surface enhanced Raman scattering from molecules on metal surfaces is the resonant excitation of plasmons associated with surface roughness.
Recent publications:
Time-Resolved Studies of Stimulated Emission from Colloidal Dye Solutions, M. Siddique, R.R. Alfano, G.A. Berger, M. Kempe, and A.Z. Genack, Opt. Lett. 21 , 450 (1996)
Acousto-Optic Imaging of Absorbing Structures with Multiply-Scattered Light, M. Kempe, M. Larionov, D. Zaslavsky, and A.Z. Genack, OSA TOPS on Advances in Optical Imaging and Photon Propagation, Vol. 2 , p. 328 ed. R.R. Alfano and J.G. Fujimoto (OSA, 1996).
Intensity and Phase Distributions in the Transition from Ballistic to Diffusive Wave Propagation, A. Chabanov, M. Stoytchev, N. Garcia, and A.Z. Genack, Advances in Optical Imaging and Photon Propagation, ed. R.R. Alfano, (OSA, 1996).
Confocal Spatial Filtering for Imaging with Ballistic Light in transillumination, M. Kempe, J. Wong and A.Z. Genack, Advances in Optical Imaging and Photon Propagation, (OSA, 1996).
Electromagnetic Resonances in Low Density Collections of Dielectric Spheres, M. Stoytchev, N. Garcia, and A.Z. Genack, Advances in Optical Imaging and Photon Propagation, ed. R.R. Alfano, (OSA, 1996).
Phase Statistics in Random Media, P. Sebbah, O. Legrand, and A.Z. Genack, OSA TOPS on Advances in Optical Imaging and Photon Propagation, Vol. 2 , p. 386 ed. R.R. Alfano and J.G. Fujimoto (OSA, 1996).
Stimulated emission from amplifying random media, M. Kempe, G.A. Berger, and A.Z. Genack, in Handbook of Optical Properties, vol. 2; Optics of Small Particles, Interfaces and Surfaces, ed. R.E. Hummel and P. Wissmann (CRC Press, Boca Raton, 1997).
Ballistic and Diffuse Light Detection in Confocal and Heterodyne Imaging Systems, M. Kempe, A.Z. Genack, W Rudolph, and P. Dorn, J. Opt. Soc. Am. A 14 , 216 (1997).
Acousto-optic tomography with multiply scattered light, M. Kempe, M. Larionov, D. Zaslavsky, and A.Z. Genack, J. Opt. Soc. Am. 14 , 1151 (1997).
Microwave transmission through a periodic three-dimensional metal-wire network containing random scatterers, M. Stoytchev, A.Z. Genack, Phys. Rev. B 55 , R8617 (1997).
Measurement of the probability distribution of total transmission in random waveguides, M. Stoytchev and A.Z. Genack, Phys. Rev. Lett. 79 , 309 (1997).
Statistics of Cumulative Phase in Microwave Radiation in Random Media, P. Sebbah, O. Legrand. B. A. van Tiggelen and A.Z. Genack, Phys. Rev. E 56 , 3619 (1997).
Field Distributions in the Crossover from Ballistic to Diffusive Wave Propagation, A. Chabanov and A.Z. Genack, Phys. Rev. E 56 , R1338 (1997).
Dynamics of Stimulated Emission from Random Media Studied by Monte Carlo Simulation, G.A. Berger, M. Kempe, and A.Z. Genack, Phys. Rev. E 56 , 6118 (1997).
Ballistic and Diffuse Light Detection in Confocal and Heterodyne Imaging Systems, M. Kempe, A.Z. Genack, W Rudolph, and P. Dorn, J. Opt. Soc. Am. A 14 , 216 (1997).
Acousto-optic tomography with multiply scattered light, M. Kempe, M. Larionov, D. Zaslavsky, and A.Z. Genack, J. Opt. Soc. Am. A 14 , 1151 (1997).
Multiple Scattering of Microwaves, P. Sebbah and A.Z. Genack, in New Aspects of Electromagnetic and Acoustic Wave Diffusion, Springer Tracts of Modern Physics, Vol.144 , p. 28 ed. by B. van Tiggelen, (Springer, Berlin, 1998).
Low-threshold lasing at the edge of a photonic stop band in cholesteric liquid crystals, V.I. Kopp, B. Fan, H.K.M. Vithana, and A.Z. Genack, Opt. Lett. 23 , 1707 (1998).
Fluctuations in photon local delay time and their relation to phase spectra in random media, P. Sebbah, O. Legrand and A.Z. Genack, Phys. Rev. E 59 , 2406 (1999).
Observations of non-Rayleigh statistics in the approach to localization, M. Stoytchev, A.Z. Genack, Opt Lett. 24 , 262 (1999).
Statistics of wave dynamics in random media, A.Z. Genack, P. Sebbah, M. Stoytchev, and B.A. van Tiggelen, Phys. Rev. Lett. 82 , 715 (1999).
Density of states and lasing at the edge of a photonic stop band in dye doped cholesteric liquid crystals, V.I. Kopp and A.Z. Genack, SPIE Proceedings vol. 3623, Organic Photonic Materials and Devices (1999).
Lasing at the edge of a photonic stop band in cholesteric liquid crystals, A.Z. Genack and V.I. Kopp, IEEE LEOS 13, 8 (1999).
Delay-time statistics for diffuse waves, B.A. van Tiggelen, P. Sebbah, M Stoytchev, and A.Z. Genack, Phys. Rev. E 59, 7166 (1999).
Observations of photon localization and exponential scaling of intensity fluctuations, A.Z. Genack and A. A. Chabanov, in Frontiers of Laser Physics and Quantum Optics, ed. By Z. X. Xu, S. Xie, S-Y Zhu and M. O. Scully, p. 197-202 (Springer, 2000).
Spatial distribution of lasing at the edge of a photonic stop band in dye-doped cholesteric liquid crystals, V.I. Kopp, Z-Q Zhang, and AZ. Genack, Proc. SPIE Vol. 3939, p. 39-48, Organic Photonic Materials and Devices II, Donal D. Bradley; Bernard Kippelen; Eds. (2000)
Statistical approach to photon localization, A. A. Chabanov, M. Stoytchev, and A. Z. Genack, Nature 404 , 850 (2000).
Field and intensity correlation in random media, P. Sebbah, R. Pnini and A.Z. Genack, Phys. Rev. E 62, 7348 (2000).
Statistical approach to photon localization, A.Z. Genack, A.A. Chabanov, in Waves and Imaging through Complex Media ed. by P. Sebbah, p. 53-84 (Kluwer, Dordrecht, 2001).
Large coherence area thin-film photonic stop-band lasers, V.I. Kopp, Z.-Q. Zhang and A.Z. Genack, Phys. Rev. Lett. 86, 1753 (2001). [APS]
Photon Localization in Resonant Media, A.A. Chabanov and A.Z. Genack, Phys. Rev. Lett. 87, 153901 (2001). [APS]
Statistics of dynamics of localized waves, A.A. Chabanov and A.Z. Genack, Phys. Rev. Lett. 87, 233903 (2001).
Spatial field correlation: the building block of mesoscopic fluctuations, P. Sebbah, B. Hu, A.Z. Genack, R. Pnini and B. Shapiro, Phys. Rev. Lett. 88, 123901 (2002).
Anisotropic Photonic Band Gap Structures, V.I. Kopp. P.V. Shibaev. R. Bose, and A.Z. Genack, Proc. SPIE, 4655, 141 (2002).
Twist defect in chiral photonic structures, V.I. Kopp and A.Z. Genack, Phys. Rev. Lett. 88, 033901 (2002). [APS]
Lasing from a stiff chain polymeric lyotropic cholesteric liquid crystal, P.V. Shibaev, K. Tang A. Genack, V.I. Kopp, M. M. Green, Macromolecules 35, 3022 (2002).
Photon localization in resonant media, A.A. Chabanov and A.Z. Genack, Optics and Photonics News, 13, 25 (2002).
Transmission through chiral twist defect in anisotropic periodic structures, V.I. Kopp, R. Bose and A.Z. Genack, Opt. Lett. 28, 349 (2003).
Photonic Materials Based on Mixtures of Cholesteric Liquid Crystals with Polymers, P.V. Shibaev, V.I. Kopp and A.Z. Genack, to be published in Jour. Phys. Chem. B, 107 6961 (2003).
Mesoscopic dynamics: a study of phase, A.Z. Genack, A.A. Chabanov, P. Sebbah and B.A. van Tiggelen in Wave Scattering in Complex Media, ed by and B.A. van Tiggelen and S.E Skipetrov (Kluwer, Dordrecht, 2003).
Photon localization in resonant media, A.A. Chabanov and A.Z. Genack in Wave Scattering in Complex Media, ed by and B.A. van Tiggelen and S.E Skipetrov (Kluwer, Dordrecht , 2003).
Lasing in chiral photonic structures, V.I. Kopp, Z.-Q. Zhang and A.Z. Genack, Prog. in Quant. Elec., to appear (2003).
Breakdown of diffusion in dynamics of extended waves in mesoscopic media, A.A. Chabanov, A.Z. Genack and Z.-Q. Zhang, Phys. Rev. Lett. 90, 203903-1 (2003). [APS link]
Double helix chiral fibers, V.I. Kopp and A.Z. Genack, Opt. Lett. 28, 1876 (2003).
Photonic Materials Based on Mixtures of Cholesteric Liquid Crystals with Polymers, P.V. Shibaev, V.I. Kopp and A.Z. Genack, Jour. Phys. Chem. B, 107 6961 (2003).
Narrowing of spontaneous emission and lasing in lyotropic and thermotropic liquid crystals, P.V. Shibaev and A.Z. Genack, Liq. Cryst. 30, 1365-1368 (2003).
Lasing from chiral photonic band gap materials based on cholesteric glasses, P.V. Shibaev, V.I. Kopp, A.Z. Genack, and E. Hanelt, Liq. Cryst. 30, 1391-1400 (2003).
Polarization correlation in random media, A.
Impact of weak localization in the time domain, S. K. Cheung, X. Zhang, Z. Q. Zhang, A.A. Chabanov , and A. Z. Genack , Phys. Rev. Lett. 92, 173902 (2004).
Chiral fiber Bragg gratings, A.Z.
Dynamic correlation in wave propagation in random media, A.
Chiral fiber gratings, VI. Kopp, V.M. Churikov, J. Singer, N. Chao, D. Neugroschl, and A.Z.
Lasing and narrowing of spontaneous emission from responsive cholesteric films, P. V. Shibaev, J. Madsen and A. Z.
Impact of weak localization on wave dynamics: crossover from quasi-1D to slab geometry, Z. Q. Zhang, S. K. Cheung, X. Zhang, A.
The Statistics of the Mesoscopic Field, A.
Chiral fiber gratings polarize light, VI. Kopp, A.Z.
Photon Localization Laser: Low-Threshold Lasing in a Random Amplifying Layered Medium via Wave Localization, V. Milner and A. Z. Genack, Phys. Rev. Lett. 94, 073901 (2005).
Synchronization of optical polarization conversion and scattering in chiral optical fibers, V.I. Kopp, V.M. Churikov, and A.Z. Genack, Proceedings of SPIE vol. 5742 (SPIE, Bellingham, WA, 2005).
From planar to fiber chiral gratings, A. Z. Genack, V. I. Kopp, V. M. Churikov, J. Singer,
N. Chao and D. Neugroschl, in Emerging Liquid Crystal Technologies, ed. by L.C. Chien, Proceedings of SPIE vol. 5742 (SPIE, Bellingham, WA, 2005) p. 90.
Light Controllable Tuning and Switching of Lasing in Chiral Liquid Crystals, P V. Shibaev, R. L. Sanford, D. Chiappetta, V. Milner, A. Z. Genack, A. Bobrovsky, Optics Express 13, 2358 (2005).
Optics: Waves in random media, A. Z. Genack, B. A. van Tiggelen, P. Sebbah and A. A. Chabanov, in Encyclopedia of Condensed Matter Physics, Elsevier (2005).
Electromagnetic fluctuations, correlation and localization in the time domain, A.Z. Genack, AA. Chabanov, B. Hu, Z.-Q. Zhang and P. Sebbah, in Complex Mediums VI: Light and Complexity ,ed. by M. McCall and M. Noginov, Proceedings of SPIE vol. 5924 (SPIE, Bellingham, WA, 2005) p. 592404.
Statistics of the near-field speckle pattern in transmission through random media, P. Sebbah, B. Hu, A. A. Chabanov, and A. Z. Genack, in Complex Mediums VI: Light and Complexity, ed. by M. McCall and M. Noginov, Proceedings of SPIE vol. 5924 (SPIE, Bellingham, WA, 2005) p. 59240T.
Statistics of the Mesoscopic Field, A. A. Chabanov and A. Z. Genack, Phys. Rev. E 72, 055602 (2005).
Signatures of photon localization, A. Z. Genack and A. A. Chabanov, J. Phys. A: Math. Gen. 38 10465-10488 (2005).
Synchronization of optical polarization conversion and scattering in chiral fibers, V. I. Kopp, V. M. Churikov, and A. Z. Genack, Opt. Lett. 31, 571 (2006).
Quasimodes of spatially extended field distributions within nominally localized random waveguides, P. Sebbah, B. Hu, J. Klosner, and A. Z. Genack, Phys. Rev. Lett. 96, 183902 (2006).
Localized Modes in Open One-Dimensional Dissipative Random Systems, K. Yu. Bliokh, Yu. P. Bliokh, V. Freilikher, A.Z. Genack, B. Hu, and P. Sebbah, Phys. Rev. Lett. 97, 243904 (2006).
Conference Review: Meta 2006 highlights random, periodic optical metamaterials, V. M. Shalaev and A. Z. Genack, Laser Focus, 30 (August 2006).
Speckle evolution of diffusive and localized waves, S. Zhang, B. Hu, P. Sebbah, and A. Z. Genack, Phys. Rev. Lett. 99, 063902 (2007).
Observation of singularities in multiply-scattered microwave fields, S. Zhang, B. Hu, Y. Lockerman, P. Sebbah, and A. Z. Genack, Jour. Opt. Soc. Am. A 24, A33 (2007).
Effect of absorption on quasimodes of a random waveguide, P. Sebbah, B. Hu, V. I. Kopp, A. Z Genack, Jour. Opt. Soc. Am B 24, A77 (2007).
Single and double helix chiral fiber sensors, V. I. Kopp, V. M. Churikov, G. Zhang, J. Singer, C. W. Draper, N, Chao, D. Neugroschl and A.Z. Genack, Jour. Opt. Soc. Am. B 24, A48 (2007).
Chiral fiber gratings: perspectives and challenges for sensing applications" V.I. Kopp, V.M. Churikov, G. Zhang, J. Singer, C.W. Draper, N. Chao, D. Neugroschl, and A.Z. Genack, Proceedings of SPIE 6619, 66190B (2007).
Statistics of random fields in the vortex core, S. Zhang and A. Z. Genack, Phys. Rev. Lett. 99, 203901 (2007).
Facilities:
microwave facilities include:
Coherent Autoscan 899-29 high-resolution computer controlled tunable dye laser
Hewlett Packard network analyzers from 50 MHZ - 40 GHz and from 50 MHZ - 40 GHz
Pulsed microwave spectrometer from 4-26 GHz with subnanosecond time resolution
Tektronix digital 11801B digital sampling oscilloscope
Wiltron 6759-B10 swept frequency synthesizer from 10 MHz - 26 GHz
Traveling Wave Tube Amplifiers
laser facilities include
Coherent Radiation argon ion-laser pumping swept single frequency dye laser
Quantronix YAG laser synchronously pumping mode locked, cavity dumped Coherent Radiation picosecond dye laser producing of 1 picosecond duration
Time correlated single photon detection apparatus with 30 picosecond time resolution
Princeton Instruments CCD detector camera for material imaging
Spex Industries Triplemate Spectrometer
- B.A. Columbia College- 1964
- Ph.D. Columbia University - 1973
Dr. Genack is a native of Queens. From 1973-75 he was a Research Associate at City College of CUNY. He spent the following two years as a Research Associated at the IBM Research Laboratory in San Jose, CA. He moved back to the east coast in 1977 to take a position at the Corporate Research Laboratories of the Exxon Research and Engineering Company. Dr. Genack joined the faculty of Queens College in 1984. He is a member of New York State Center for Advanced Technology on Ultrafast Photonics and Applications at the City University. He is a Fellow of the American Physical Society and a member of the Optical Society of America
SB B212; (718) 997-3373
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Physics 204
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Optics (11 MB)
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Photon Localization and Mesoscopic Fluctuations
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Waves in condensed matter
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Interference and Modes