Theoretical Condensed Matter Physics and Quantum Optics
Sajeev John is a ''University Professor'' at the University of Toronto and Government of Canada Research Chair holder. He received his Bachelor's degree in physics in 1979 from the Massachusetts Institute of Technology and his Ph.D. in physics at Harvard University in 1984. His Ph.D. work at Harvard introduced the theory of classical wave localization and in particular the localization of light in three-dimensional strongly scattering dielectrics.
From 1986-1989 he was an assistant professor of physics at Princeton University. While at Princeton, he co-invented (1987) the concept of photonic band gap materials, providing an easier route to his original conception (1984) of the localization of light. In the fall of 1989 he joined the senior physics faculty at the University of Toronto.
Professor John is the winner of the 2001 King Faisal International Prize in Science,
which he shared with C. N. Yang. He is also the first ever winner of Ontario's Platinum Medal for Science and Medicine in 2002.
Dr. John is the winner of the Institute of Electrical and
Electronics Engineers (IEEE) International Quantum Electronics Award in 2007 for ''the invention and development of light-trapping crystals
and elucidation of their properties and applications''. He is also the winner of the
2008 IEEE Nanotechnology Pioneer Award and the
2013 IEEE David Sarnoff Award. Prof. John was awarded the
Killam Prize in Natural Sciences for 2014 by the Canada Council for the Arts.
Most recently, he was appointed as an Officer of the Order of Canada
"For his revolutionary contributions to optical sciences, notably for his role in the development of new structures capable of harnessing the
flow of light."
Dr. John is also the first ever winner of
Brockhouse Canada Prize in 2004, which he shared with materials chemist Geoff Ozin for their ground-breaking interdisciplinary work on photonic
band gap materials synthesis. In 2011, Prof. John was selected as a Thomson-Reuters
Citation Laureate. Prof. John has been awarded the Guggenheim Fellowship (USA)
and the Humboldt Senior Scientist Award (Germany).
In 2007, Dr. John was awarded the C.V. Raman Chair Professorship of the Indian Academy of Sciences.
Prof. John is a Fellow of the American Physical Society, the Optical Society of America, the Royal Society of Canada, and a member of the
Max-Planck Society of Germany.
Prof. John's other awards include the 2007 Brockhouse Medal for Condensed Matter Physics and Materials Physics, the 2004 Rutherford Medal of the Royal Society of Canada, the Killam Research Fellowship of the Canada Council for the Arts (1998-2000), the 1997 Steacie Prize of the National Research Council, the first ever McLean Fellowship at the University of Toronto and the Herzberg Medal of the Canadian Association of Physicists.
His external affiliations have included Adjunct Chair Professor at Soochow
University in Suzhou China, Adjunct Professor at King Abdulaziz University, Saudi Arabia, Guest Professor at Sun Yat Sen University in China, External Scientific Member of the Max Planck Institute for Microstructure Physics in Germany, Meyerhoff Visiting Professor at the Wiezmann Institute in Israel and Fellow of the Canadian Institute for Advanced Research.
Current research: Photonics, Nano-science, Solar energy harvesting, Bio-sensors for Medical Diagnostics, Room Temperature Bose-Einstein Condensation
Phone: (416) 978-3459 Fax: (416) 978-2537
john at physics.utoronto.ca
Research Interests and Contributions
Electromagnetism is the fundamental mediator of interactions in condensed matter and atomic physics. It is extraordinary that such a basic interaction can be tailored within an artificial material, leading to a variety of new physical phenomena. This began with the study of classical wave localization in disordered media, eventually focusing on electromagnetic waves. It was then theoretically predicted and later experimentally demonstrated that in a new class of dielectrics
(see movie clip) light can exhibit strong localization. These dielectric materials are the photonic analogs of semi-conductors and have important technological applications. We are studying the implications of light-trapping in both classical and quantum-electrodynamics. This has applications for optical communications, information technology, lighting, solar energy harvesting, and medical diagnostics to name a few.
Solar Energy Harvesting with Thin-Film
We have demonstrated the efficacy of thin-film photonic crystals for solar light trapping and electrical power generation. These photonic crystals consist of various (conical or inverted-pyramid) nano-pore arrays. These structures absorb more sunlight than a longstanding benchmark known as the Lambertian limit [Solar light trapping in slanted conical pore photonic crystals: beyond statistical ray trapping J. of Applied Physics 113, 154315 (2013)]. The novel underlying physics of these solar cell architectures comes from an effect known as Parallel-to-Interface Refraction and subsequent light-trapping in slow group velocity modes. Rather than making use of a photonic band gap, these solar cells rely on the ability of photonic crystals to greatly increase the electromagnetic density of states over selected frequency regimes.
With only one micron (equivalent bulk thickness) of silicon it is possible to absorb nearly 85% of all available sunlight in the wavelength range of 300-1100 nm. This enables a one-micron thick silicon photonic crystal to achieve a power conversion efficiency of 17.5%, surpassing commercial silicon solar cells that use up to 300 microns of silicon. With 10-micron thickness of silicon it is possible to reach a photo-current density of 42.5 mA/cm2 (from sunlight in the 300-1100 nanometer wavelength range), not far from the 100% solar absorption limit of 43.5 mA/cm2. By including solar absorption over the full 300-1200 nm range and using an optimized doping profile that minimizes
Auger and surface recombination, it possible to reach as high as 30% power conversion efficiency using a thin and flexible 10-micron-thick sheet of silicon. In a 15-micron-thick silicon solar cell with interdigitated back contacts, it is possible to achieve even higher power conversion efficiency, well above the world record of 26.7%
and close to the Shockley-Queisser thermodynamic limit of 33%.
We have also shown near perfect solar absorption in ultra-thin-film Gallium Arsenide photonic crystals. With only 300 nm of GaAs, it is possible to absorb 99.5% of all available sunlight in the wavelength range of 300 nm- 860 nm. Using only 200 nm equivalent bulk thickness of GaAs, it is possible to realize a world record power conversion efficiency of 30% for a single-junction solar cell.
We are considering ways to improve the efficiency of Perovskite Solar Cells using light-trapping effects.
There are important consequences of photon localization and photonic band gap materials in the context of quantum electrodynamics [see for instance Physical Review Letters 64, 2418 (1990)]. These novel consequences are related to the fact that when an atom or molecule with a resonant optical transition of frequency coincident with the photonic band gap is placed inside a PBG material, spontaneous emission of light from the atom is inhibited. Instead, light remains localized in the vicinity of the atom in the form of a photon-atom bound state.
Some consequences include zero-threshold laser activity [Phys. Rev. Lett. 74, 3419 (1995)], low threshold nonlinear optical response [Phys. Rev. Lett. 76, 2484 (1996)], all-optical transistor action [Phys. Rev. Lett. 78, 1888 (1997)], and single-atom optical memory [Phys. Rev. Lett. 79, 5238 (1997)].
A very striking discovery [Physical Review Letters 103, 233601 (2009)] is that nearly complete coherent control of the excitation dynamics of quantum dots by picosecond optical pulses in a photonic band gap waveguide. In particular it is possible to achieve and maintain complete inversion of quantum dots with femto-joule optical pulses. This provides a basis for a multi-wavelength-channel, all-optical-transistor in a photonic band gap microchip that can perform optical logic and optical information processing.
Room Temperature Equilibrium Bose-Einstein Condensation
We have demonstrated that charge carrier (electron-hole) dynamics in a semiconductor quantum well can be significantly modified by the electromagnetic environment of a Photonic Band Gap [Physical Review Letters 99, 046801 (2007)]. Unlike the situation in a simpler one-dimensional optical cavity, bound electron-hole pairs (excitons) in a 3-D Photonic Crystal can have very long lifetimes with respect to radiative recombination, allowing time for thermodynamic equilibrium to be established. The effective mass of the exciton can be reduced by four orders of magnitude through dressing by photonic band edge photons and the energy range over which this effect persists can exceed the room-temperature-scale This may lead to novel quantum effects such as Bose-Einstein condensation at room temperature and new types of exciton-polariton lasers [Nature Scientific Reports 4, 7432 (2015)Nature Scientific Reports 4, 7432 (2015)].
Medical Diagnostics in a Photonic-Band-Gap Lab-on-a-Chip
Lab-on-a-chip (LoC) optical bio-sensors are promising paradigms for portable, convenient, and inexpensive medical testing. They enable diagnosing diseases at early stages at home without requiring expensive, time-consuming, external laboratory testing. Our paper, Optical Bio-sensing of Multiple Disease Markers in a Photonic-Band-Gap Lab-on-a-Chip: A Conceptual Paradigm [Phys. Rev. Applied 3, 034001 (2015)] describes the application of photonic crystals to this subject. Unlike previous optical bio-sensors that are based on the shift of a sharp optical resonance in response to the binding of a disease-identifying-protein to an optical micro-cavity, we propose a new paradigm for a medical lab-on-a-chip. This involves a photonic band gap micro-chip with micro-fluidic channels embedded in a glass slide that can provide a much more detailed spectral fingerprint of various diseases or various stages of a given disease using the cascaded transmission of laser light through the chip. It allows, for the first time, the instantaneous identification and differentiation of multiple disease markers in a single diagnostic sample, using transmission of light through a centimeter scale slide.
A remarkable property of Photonic Band Gap waveguides is that they can confine light in the low-refractive-index region (e.g., water in our biosensor). This is especially beneficial for biosensing since the analytes usually reside in the low-refractive-index region. This facilitates simultaneous realization of high sensitivity and low limit of detection,
a pair of conflicting figures of merit for conventional optical sensors.
A new spectroscopic technique for turbid media is known as Diffusing Wave Spectroscopy. This enables measurement of structural and temporal properties of an opaque medium in which light undergoes a multiple scattering path. An application of this method is in diagnostic medical imaging [Journal of Biomedical Optics 1 (2), 180 (1996)]. Using multiple scattering of near-infrared light, it is possible to image brain and breast tumors non-invasively and inexpensively. Unlike X-rays that use very short wavelength radiation and magnetic resonance imaging that uses very long wavelength radiation, near IR light is an intermediate frequency probe which is sensitive to metabolic processes such as the local oxygenation level of hemoglobin. Unlike earlier methods based on the diffusion theory of light in tissue that provides resolution on the scale of a millimeter, Diffusing Wave Spectroscopy offers the possibility of resolution on the scale of 10 microns. Rather than tracking only the intensity fluctuations of diffusing light due to an inhomogeneity within a turbid medium, this new technique tracks changes in the optical Wigner Coherence function. This holds the possibility of early detection of tumors during the early metabolic stages of formation before structural damage takes place.
Related to the theory of multiple light scattering in disordered media is the phenomenon of random lasing. Our theoretical models describe (i) how this effect occurs in a photon diffusion model [Physical Review A 54, 3642 (1996) Theory of Lasing in a Multiple Scattering Medium] and (ii) the long-sought-after quantum statistical properties of light emission from the random laser [Physical Review E 69, 046603 (2004) Theory of Photon Statistics and Optical Coherence in a Multiple-Scattering Random Laser Medium].
The microscopic mechanism for high temperature superconductivity is still an unsolved problem in theoretical physics. We have suggested the concept of spin-flux as a possible microscopic starting point for a first principles theory of non-Fermi liquid behavior in the normal state of these superconductors. This proposal suggests that a fundamental Law of Nature remains to be fully recognized before a clear microscopic understanding of high Tc superconductivity is possible. This Law of Nature is the existence of a new quantum number in a correlated electron system that manifests itself when an electron undergoes a somersault in its internal coordinate system as it traverses a closed loop in external coordinate space. This classical somersault trajectory can be described in terms of a "flux" that couples directly to the spin of the electron rather than its charge. This leads to the appearance of quantized spin-flux, a new degree of freedom in a many-electron system.
In our many-electron state exhibiting spin-flux, charge carriers added to the antiferromagnetic normal state are naturally clothed by vortex textures in the antiferromagnetic background. We have shown that these charged solitons are bosonic collective modes and can explain non-Fermi liquid behavior and d-wave charge carrier pairing in a purely repulsive, interacting electron system. Remarkable agreement is found between this theory and numerous independently observed electronic, magnetic, and optical properties of the high temperature superconductors. For a brief review see [A Microscopic Model for D-Wave Charge Carrier Pairing in High Tc Superconductors: What Happens when Electrons Somersault?]. Further quantitative comparison with detailed experimental measurement of the magnetic structure factor is found in [Physical Review B 69, 224515 (2004) Incommensurate magnetic neutron scattering in cuprate high Tc superconductors: Evidence for charged meron-vortices].
Research Group Members: Past and Present
- Jian Wang
- Puru Voruganti
- Andrei Golubentsev
- Manish Mehta
- Tran Quang
- Axel Muller-Groeling
- Gendi Pang
- Vladimir Stephanovich
- Kurt Busch
- Alongkarn Chutinan
- Rongzhou Wang
- Georg von Freymann
- Dragan Vujic
- Hiroyuki Takeda
- Chongjun Jin
- Ramy El-Ganainy
- Guillaume Demesy
- Alexei Deinega
- Rongjuan Liu
- Alagappan Gandhi
- Khai Le
- Jian-hua Jiang
- David Hagenmuller
- Sergey Eyderman
- Wah-Tung Lau
- Qingguo Du
- Ibrahim Baydoun
Former Ph.D. Students
- Chiranjeeb Roy
- Xun Ma
- Pranai Vasudev
- Stephen Foster
- Abdullah Al-Rashid
Current Ph.D. Students
- Sayak Bhattacharya
- Xiwen Zhang
Selected Publications (Chronological List)
"Electromagnetic Absorption in a Disordered Medium near a Photon Mobility
Edge", Sajeev John, Phys. Rev. Lett. 53, 2169 (1984). ABSTRACT
"Spin Glass State of a Randomly diluted Granular Superconductor", Sajeev
John and T.C. Lubensky, Phys. Rev. Lett. 55, 1014 (1985).
"Theory of the Electron Band Tails and the Urbach Optical Absorption Edge",
Sajeev John, C. Soukoulis, Morrel H. Cohen and E.N. Economou, Phys.
Rev. Lett. 57, 1777 (1986). ABSTRACT
"Strong Localization of Photons in Certain Disordered Dielectric Superlattices",
Sajeev John, Phys. Rev. Lett. 58, 2486 (1987). ABSTRACT
"Localization and the Density of States for an Electron in a Quantized
Elastic Continuum", Sajeev John, Physical Review B 35, 9291
"Density of States for an Electron in a Correlated Gaussian Random Potential:
Theory of the Urbach Tail", Sajeev John, M.Y. Chou, M.H. Cohen and C.M.
Soukoulis, Phys. Rev. B 37, 6963 (1988). ABSTRACT
"Temperature Dependence of the Urbach Edge: A Theory of Multiple Phonon
Absorption and Emission Sidebands", C. Grein and Sajeev John, Phys.
Rev. B 39, 1140 (1989). ABSTRACT
1990 - 1995
''Localization of Light'', S. John,
Today, May (1991), Cover Story.
''Quantum Electrodynamics Near a Photonic Band Gap: Photons Bound States
and Dressed Atoms'', S. John and J. Wang, Phys. Rev. Lett. 64,
2418 (1990). ABSTRACT
''Nonlinear Optical Solitary Waves in a Photonic Bandgap'', S. John and
N. Akozbek, Physical Review Letters 71, 1168 (1993). ABSTRACT
''Topological Magnetic Solitons in the Two-Dimensional Mott-Hubbard Gap'',
S. John and A. Golubentsev, Physical Review Letters 71, 3343
"Spontaneous Emission near the Edge of a Photonic Bandgap", Sajeev John
and Tran Quang, Physical Review A 50 1764 (1994). ABSTRACT
"Spin-flux and Magnetic Solitons in an Interacting Two-Dimensional Electron
Gas: Topology of Two-Valued Wavefunctions", Sajeev John and A. Golubentsev,
Review B51, 381 (1995). ABSTRACT.
''Localization of Superradiance near a Photonic Bandgap'', S. John and
T. Quang, Phys. Rev. Lett. 74, 3419 (1995). ABSTRACT
1996 - 1997
''Optical Coherence Propagation and Imaging in a Multiple Scattering Medium'',
S. John, G. Pang and Y. Yang, Journal of Biomedical Optics 1,
number 2, 180 (1996). ABSTRACT
''Quantum Optical Spin-Glass State of Impurity Two-Level Atoms in a Photonic
Bandgap'', S. John and T. Quang, Phys. Rev. Lett. 76, 1320
''Resonant Nonlinear Dielectric Response in a Photonic Band Gap Material'',
S. John and T. Quang, Phys. Rev. Lett. 76, 2484 (1996). ABSTRACT
''Theory of Lasing in a Multiple Scattering Medium'', S. John and G. Pang,
Review A 54, 3642 (1996). ABSTRACT
"Collective Switching and Inversion without Fluctuation of Two-Level Atoms
in Confined Photonic Systems", Sajeev John and Tran Quang, Physical
Review Letters 78, 1888 (1997). ABSTRACT
"Multiphoton Localization and Propagating Quantum Gap Solitons in a Frequency
Gap Medium", Sajeev John and Valery Rupasov, Physical Review Letters
821 (1997). ABSTRACT
"Coherent Control of Spontaneous Emission Near a Photonic Band Edge: A
Single-Atom Optical Memory Device", Tran Quang, M. Woldeyohannes, Sajeev
John and G.S. Agarwal, Physical Review Letters 79 5238 (1997).
"Frozen Light", Sajeev John, Nature 390, 661 (1997). PDF
1998 - 2000
"Charged Bosons in a Doped Mott Insulator: Electronic Properties of Domain
Wall Solitons and Meron-Vortices", Mona Berciu and Sajeev John, Physical
Review B 57 9521 (1998). ABSTRACT
"Midgap States of a Two-Dimensional Antiferromagnetic Mott Insulator: Electronic
Structure of Meron-Vortices", Sajeev John, Mona Berciu and A. Golubentsev,
Letters 41 (1), 31 (1998). ABSTRACT
"Photonic Band Gap Formation in Certain Self-Organizing Systems", Kurt
Busch and Sajeev John, Physical Review E 58, 3896 (1998).
"Liquid Crystal Photonic Band Gap Materials: The Tunable Electromagnetic
Vacuum", Kurt Busch and Sajeev John, Physical Review Letters 83
(5), 967-970 (1999). ABSTRACT
"Coherent control of spontaneous emission near a photonic band edge: A
qubit for quantum computation", Mesfin Woldeyohannes and Sajeev John, Physical
Review A 60(6), 5046-5068 (1999). ABSTRACT
"Quantum dynamics of charged and neutral magnetic solitons: Spin-charge
separation in the one-dimensional Hubbard model", Mona Berciu and Sajeev
John, Physical Review B 61 (15), 10015-10028 (2000). ABSTRACT
"A microscopic model for d-wave charge carrier pairing and non-Fermi-liquid
behavior in a purely repulsive 2D electron system", Mona Berciu and Sajeev
John, Physical Review B 61 (24), 16454-16469 (2000). ABSTRACT
"Large-scale synthesis of a silicon photonic crystal with a complete three-dimensional
bandgap near 1.5 micrometres", Alvaro Blanco, Emmanuel Chomski, Serguei
Grabtchak; Marta Ibisate, Sajeev John, Stephen W. Leonard, Cefe Lopez,
Francisco Meseguer, Hernan Miguez, Jessica P. Mondia, Geoffrey A. Ozin,
Ovidiu Toader and Henry M. van Driel, Nature 405 (6785), 437-440
2001 - 2003
- "Optical Trapping, Field Enhancement, and Laser Cooling in Photonic Crystals", Ovidiu Toader, Sajeev John and K. Busch, Optics Express vol.8, no. 3, pg 271- (2001). ABSTRACT PDF
- "Proposed Square
Spiral Microfabrication Architecture for Large Three-Dimensional Photonic Band
Crystals", Ovidiu Toader and Sajeev John, Science vol. 292, 1133 (2001). ABSTRACT PDF
- "Photonic Band Gap Materials: Towards an All-Optical Micro-Transistor", Sajeev John and Marian Florescu, Journal of Optics A: Pure and Applied Optics 3, S103 (2001). ABSTRACT PDF
- "Theory of Fluorescence in Photonic Crystals", Nipun Vats, K. Busch, Sajeev John, Physical Review A 65, 043808 (2002). ABSTRACT PDF POSTSCRIPT
- "Coherent Control of Spontaneous Emission near a Photonic Band Edge",
M. Woldeyohannes and Sajeev John, Journal of Optics B: Quantum and Semiclass. Opt. 5, R43-R82 (2003). PDF
- "Diffractionless Flow of Light in All-Optical Micro-chips", A. Chutinan, Sajeev John, and O. Toader, Physical Review Letters 90, 123901 (2003) . ABSTRACT PDF POSTSCRIPT
- "Photonic Band Gap Materials based on Tetragonal Lattices of Slanted Pores", O. Toader, M. Berciu, and Sajeev John, Physical Review Letters 90, 233901 (2003). ABSTRACT PDF POSTSCRIPT
- "Optical Properties of a Silicon Square Spiral Photonic Crystal" ,
S. Kennedy, M. Brett, O. Toader, and Sajeev John, Journal of Photonics and Nanostructures, Vol. 1, Issue 1, 37 (2003). PDF
2004 - 2005
- "Photonic Band Gap Synthesis
by Holographic Lithography" Ovidiu Toader, Tim Chan, and Sajeev John, Physical Review Letters 92, 043905 (2004). ABSTRACT PDF POSTSCRIPT
- "Theory of Photon Statistics and Optical Coherence in a Multiple-Scattering Random Laser Medium", Lucia Florescu and Sajeev John, Physical Review E 69, 046603 (2004). ABSTRACT
- "Theory of a One-Atom Laser in a Photonic Band Gap Micro-chip", Lucia Florescu, Sajeev John, Tran Quang, and R.Z. Wang, Physical Review A 69, 013816 (2004). ABSTRACT PDF POSTSCRIPT
- "Photonic band gap enhancement in frequency-dependent dielectrics", Ovidiu Toader and Sajeev John, Physical Review E 70, 046605 (2004). ABSTRACT PDF
- "Photon Statistics and Optical Coherence Properties of Light Emission
from a Random Laser", Lucia Florescu and Sajeev John, Physical Review
Letters 93, 013602 (2004). ABSTRACT
- "Magnetic structure factor in cuprate superconductors: Evidence for charged meron vortices", Mona Berciu and Sajeev John, Physical Review B 69, 224515 (2004). ABSTRACT PDF
- "Engineering the Electromagnetic Vacuum for Controlling Light with Light in
a Photonic Band Gap Micro-chip", R. Z. Wang and Sajeev John, Physical Review A 70, 043805 (2004). ABSTRACT PDF
2005 - 2006
- "Diffractionless Flow of Light in 2D-3D Photonic Band Gap
Hetero-structures: Theory, Design Rules, and Simulations", Alongkarn Chutinan and Sajeev John, Physical Review E 71, 026605 (2005). ABSTRACT PDF
- "Pulse re-shaping in photonic crystal waveguides and micro-cavities with
Kerr-nonlinearity: Critical Issues for all-optical switching", Dragan Vujic and Sajeev John, Physical Review A 72, 013807 (2005). ABSTRACT PDF
- "Slanted Pore Photonic Band Gap Materials",
Ovidiu Toader and Sajeev John, Physical Review E 71, 036605 (2005).
- "Light Localization for Broadband Integrated Optics in Three
Dimensions", A. Chutinan and Sajeev John, Physical Review B 72, 16, 161316 (2005).
- "Elastic Photonic Crystals:
From Colour Fingerprinting to Enhancement of Photoluminescence", A. Arsenault, T. J. Clark, G. Von Freymann, E. Vekris, L.
Cademartiri, S. Wong, V. Kitaev, I. Manners, Sajeev John, G. A. Ozin,
Nature Materials 5 (3): 179-184 March (2006). PDF
- "New route towards three-dimensional
photonic band gap materials: Silicon double inversion of Polymeric
Templates", N. Tetreault, G. von Freymann, M. Deubel, M. Hermatschweiler, F. Perez-Willard, Sajeev John, M. Wegener, G.A. Ozin, Advanced Materials 18 (4): 457, Feb 17 (2006). ABSTRACT
- "Direct Laser Writing of Three-Dimensional
Photonic Crystals in High Index of Refraction Chalcogenide Glasses", G. von Freymann, S. Wong, G. A. Ozin, Sajeev John, F. Perez-Willard,
M. Deubel, M. Wegener, Advanced Materials Vol. 18, Issue 3, February,
2006, Pages: 265-269. ABSTRACT
- "3+1 Dimensional Integrated Optics with Localized Light in a
Photonic Band Gap",
A Chutinan and Sajeev John, Optics Express 14 (3): 1266-1279, Feb 6,
- "3D-2D-3D photonic crystal heterostructures by direct laser writing", M. Deubel, M. Wegener, S. Linden, G. Von Freymann, and Sajeev John, Optics Letters 31 (6): 805-807 March 15 ( 2006) ABSTRACT PDF
- "Photonic band-gap formation by optical-phase-mask lithography", Timothy Y. M. Chan, Ovidiu Toader, and Sajeev John, Physical Review E 73, 046610 (2006) ABSTRACT PDF
- ''Nonlinear Bloch waves in resonantly doped photonic crystals'', Artan Kaso and Sajeev John, Physical Review E 74, 046611 (2006) ABSTRACT PDF
- "Localized light orbitals: Basis states for three-dimensional photonic crystal microscale circuits", Hiroyuki Takeda, Alongkarn Chutinan and Sajeev John, Physical Review B 74, 195116 (2006). ABSTRACT PDF POSTSCRIPT
"Diamond photonic band gap synthesis by umbrella holographic lithography",
Ovidiu Toader, Timothy Y. M. Chan, and Sajeev John, Appl. Phys. Lett. 89, 101117 (2006); doi:10.1063/1.2347112 (3 pages) ABSTRACT PDF
2007 - 2009
- "Electromagnetically Induced Exciton Mobility in a Photonic Band Gap", Sajeev John and Shengjun Yang, Physical Review Lett. 99 , 046801 (2007). ABSTRACT PDF
- "Exciton dressing and capture by a photonic band edge", Shengjun Yang and Sajeev John, Physical Review B 75, 235332 (2007). ABSTRACT PDF
- "Molding light flow from photonic band gap circuits
to microstructured fibers", James Bauer and Sajeev John, Applied Physics Letters 90, 261111 (2007). ABSTRACT PDF
- "Nonlinear Bloch waves in metallic photonic band-gap filaments", Artan Kaso and Sajeev John, Physical Review A 76, 053838 (2007). ABSTRACT PDF
- "Coherent all-optical switching by resonant quantum-dot distributions in photonic band-gap
waveguides", Dragan Vujic and Sajeev John, Physical Rreview A 76, 063814 (2007).
- "Broadband optical coupling between microstructured fibers and photonic band gap circuits:
Two-dimensional paradigms", James Bauer and Sajeev John, Physical Review A 77, 013819 (2008) ABSTRACT PDF
- "Compact optical one-way waveguide isolators for photonic-band-gap microchips", Hiroyuki Takeda and Sajeev John, Physical Review A 78, 023804 (2008) ABSTRACT PDF
- "Light trapping and absorption optimization in certain thin-film photonic crystal architectures", Alongkarn Chutinan and Sajeev John, Physical Review A 78, 023825 (2008) ABSTRACT PDF
- "Templating and Replication of Spiral Photonic
Crystals for Silicon Photonics", Kock Khuen Seet, Vygantas Mizeikis, Kenta Kannari, Saulius Juodkazis, Hiroaki Misawa,
Nicolas Tetreault, and Sajeev John, IEEE Journal of Selected Topics in Quantum Electronics, Vol. 14, No. 4, July/August (2008). PDF
- "Circuits for light in holographically defined photonic-band-gap materials", Timothy Y. M. Chan and Sajeev John, Physical Review A 78, 033812 (2008). ABSTRACT
- "Exceptional Reduction of the Diffusion Constant in Partially Disordered Photonic Crystals", Costanza Toninelli, Evangellos Vekris, Geoffrey A. Ozin, Sajeev John and Diederik S. Wiersma, Physical Review Letters, 101, 123901 (2008). ABSTRACT
- "Metallic photonic-band-gap filament architectures for optimized incandescent lighting", Sajeev John and Rongzhou Wang, Physical Review A, 78, 043809 (2008). ABSTRACT
- "Optical wavelength converters for photonic band gap microcircuits", Dragan Vujic and Sajeev John, Physical Review A 79, 053836 (2009).
- "Ultrafast Population Switching of Quantum Dots in a Structured Vacuum", Xun Ma and Sajeev John, Physical Review Lett. 103, 233601 (2009). ABSTRACT PDF
- "Switching dynamics and ultrafast inversion control of quantum dots
for on-chip optical information processing", Xun Ma and Sajeev John, Physical Review A 80, 063810 (2009). ABSTRACT PDF
2010 - 2012
- "Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap", Chiranjeeb Roy and Sajeev John, Physical Review A
81, 023817 (2010). ABSTRACT PDF
- "Self-consistent Maxwell-Bloch theory of quantum-dot-population switching in photonic
crystals", Hiroyuki Takeda and Sajeev John,
Physical Review A 83, 053811 (2011).
- "Coherence and antibunching in a trapped interacting Bose-Einstein condensate", Shengjun Yang and Sajeev John, Physical Review B 84, 024515 (2011). ABSTRACT PDF
- "Quantum-dot all-optical logic in a structured vacuum", Xun Ma and Sajeev John, Physical Review A 84, 013830 (2011). ABSTRACT PDF
- "Optical pulse dynamics for quantum-dot logic operations in a photonic-crystal waveguide", Xun Ma and Sajeev John, Physical Review A 84, 053848 (2011). ABSTRACT PDF
- "Anomalous flow of light near a photonic crystal
pseudo-gap", Kyle M. Douglass, Sajeev John, Takashi Suezaki, Geoffrey A. Ozin, and Aristide
Dogariu1, Optics Express, 19, No. 25 , 25321 (2011). ABSTRACT PDF
- "Sculpturing of photonic crystals by ion beam lithography: towards complete
photonic bandgap at visible wavelengths", Saulius Juodkazis, Lorenzo Rosa, Sven Bauerdick, Lloyd Peto,
Ramy El-Ganainy and Sajeev John, Optics Express, 19, No. 7 , 5803 (2011).
- "Effective optical response of silicon to sunlight
in the finite-difference time-domain method", Alexei Deinega and Sajeev John,
Optics Letters, 37, No. 1 112 (2012).
- "Solar energy trapping with modulated silicon nanowire photonic crystals", Guillaume Demesy and Sajeev John, J. Appl. Phys., 112, 074326 (2012).
- "Solar power conversion efficiency in modulated silicon nanowire photonic
crystals", Alexei Deinega and Sajeev John, J. Appl. Phys. 112, 074327 (2012).
2013 - 2014
- "Light-trapping in dye-sensitized solar cells", Stephen Foster and Sajeev John,
Energy Environ. Sci., DOI: 10.1039/C3EE40185E (2013).
- "Solar light trapping in slanted conical-pore photonic crystals: Beyond
statistical ray trapping", Sergey Eyderman, Sajeev John and Alexei Deinega, J. Appl. Phys. 113, 154315 (2013); doi: 10.1063/1.4802442.
- "Coupled optical and electrical modeling of solar cell based on
conical pore silicon photonic crystals", Alexei Deinega, Sergey Eyderman, and Sajeev John, Journal of Applied Phys. 113, 224501 (2013); doi: 10.1063/1.4809982. ABSTRACT
- "Resonant dipole-dipole interaction in confined and
strong-coupling dielectric geometries", Ramy El-Ganainy and Sajeev John, New Journal of Physics, 15, 083033 (2013).
- "Macroscopic response in active nonlinear
photonic crystals", Gandhi Alagappan,Sajeev John, and Er Ping Li, Optics Letters 38, No. 18, 3514 (2013).
- "Light trapping and near-unity solar absorption in
a three-dimensional photonic-crystal", Ping Kuang, Alexei Deinega, Mei-Li Hsieh, Sajeev John and Shawn-Yu Lin, Optics Letters 38, No. 20, 4200 (2013).
- "Synergistic plasmonic and photonic crystal lighttrapping:
Architectures for optical upconversion
in thin-film solar cells", Khai Q. Le and Sajeev John, Optics Express, 22, Issue S1, pp. A1-A12, DOI:10.1364/OE.22.0000A1 (2014).
- "Near perfect solar absorption in ultra-thin-film
GaAs photonic crystals", Sergey Eyderman, Alexei Deinega and Sajeev John, Journal of
Materials Chemistry A, DOI: 10.1039/c3ta13655h (2014).
- "Light trapping design for low band-gap polymer solar cells," Stephen Foster and Sajeev John, Optics Express, Vol. 22, Issue S2, pp. A465-A480 (2014).
- "Photonic Crystal Architecture for Room-Temperature Equilibrium Bose-Einstein
Condensation of Exciton Polaritons," Jian-Hua Jiang and Sajeev John, Physical Review X 4, 031025 (2014).
- "Photonic Architectures for Equilibrium High-Temperature Bose-Einstein Condensation in Dichalcogenide Monolayers," Jian-Hua Jiang and Sajeev John,
Nature Magazine Scientific Reports 4, 7432 (2014).
2015 - 2017
- "Optical Biosensing of Multiple Disease Markers in a Photonic-Band-Gap Lab-on-a-Chip: A Conceptual Paradigm," Abdullah Al-Rashid and Sajeev John,
Phys. Rev. Applied 3, 034001 (2015).
- "Light-trapping optimization in wet-etched silicon photonic crystal solar cells,"
Sergey Eyderman, Sajeev John, M. Hafez, S. S. Al-Ameer, T. S. Al-Harby, Y. Al-Hadeethi and D. M. Bouwes, Journal of Applied Physics 118, 023103 (2015).
- "Waveguide-mode polarization gaps in square spiral photonic crystals,"
Rong-Juan Liu, Sajeev John and Zhi-Yuan Li, EPL, 111 54001 (2015).
"Biosensor architecture for enhanced disease diagnostics: lab-in-a-photonic-crystal," Shuai Feng, Jian-Hua Jiang, Abdullah Al Rashid and Sajeev
John, Optics Express, 24 No. 11, 12166 (2016).
- "Light-trapping in perovskite solar cells," Qing Guo Du, Guansheng Shen and Sajeev John, AIP Advances 6, 065002 (2016).
- "Light-trapping for room temperature Bose-Einstein condensation in InGaAs quantum wells," Pranai Vasudev, Jian-Hua Jiang and Sajeev John, Optics Express 24 No.13, 14010 (2016). ABSTRACT
- "Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells," Sergey Eyderman and Sajeev John, Nature Scientific Reports 6 28303 (2016). ABSTRACT
- "Achieving an Accurate Surface Profile of a Photonic Crystal for Near-Unity Solar Absorption in a Super Thin-Film Architecture," Ping Kuang, Sergey Eyderman, Mei-Li Hsieh, Anthony Post,
Sajeev John and Shawn-Yu Lin, ACS, Nano 10 (6) 6116-6124 (2016). ABSTRACT
- "Probing the intrinsic optical Bloch-mode emission from a 3D photonic crystal," Mei-Li Hsieh1, James A Bur, Qingguo Du, Sajeev John and Shawn-Yu Lin, Nanotechnology
27 415204 (2016). ABSTRACT
- "Light-trapping design for thin-film silicon-perovskite tandem solar cells," Stephen Foster and Sajeev John, Journal of Applied Physics 120, 103103 (2016).
- "Effectively infinite optical pathlength created using a simple cubic photonic crystal for extreme light trapping," Brian J. Frey, Ping Kuang, Mei-Li Hsieh, Jian-Hua Jiang,
Sajeev John and Shawn-Yu Lin, Scientific Reports 7, Article number: 4171 (2017).
- "Photonic-band-gap architectures for long-lifetime room-temperature polariton
condensation in GaAs quantum wells," Jian-Hua Jiang, Pranai Vasudev and Sajeev John, Physical Review A 96, 043827 (2017).
2018 - Present
- "Topological transitions in continuously deformed photonic crystals," Xuan Zhu, Hai-Xiao Wang, Changqing Xu, Yun Lai, Jian-Hua Jiang and Sajeev John,
Phys. Rev. B 97, 085148 (2018).
- "Designing High-Efficiency Thin Silicon Solar Cells Using Parabolic-Pore Photonic Crystals," Sayak Bhattacharya and Sajeev John,
Physical Review Applied 9, 044009 (2018).
- "Photonic crystals with a continuous, Gaussian-type surface profile for near-perfect light trapping," Ping Kuang, Sayak Bhattacharya, Mei-Li Hsieh,
Sajeev John and Shawn-Yu Lin, Journal of Nanophotonics, 12(2), 026011 (2018). ABSTRACT PDF
- "Topological light-trapping on a dislocation," Fei-Fei Li, Hai-Xiao Wang, Zhan Xiong, Qun Lou, Ping Chen, Rui-Xin Wu,
Yin Poo, Jian-Hua Jiang and Sajeev John, Nature Communications 9, 2462 (2018).
- "Three-dimensional femtosecond laser
nanolithography of crystals," Airán Ródenas, Min Gu, Giacomo Corrielli1, Petra Paič1, Sajeev John, Ajoy K. Kar and
Roberto Osellame, Nature Photonics, 1-5 (2018)
- "Towards 30% Power Conversion Efficiency in Thin-Silicon Photonic-Crystal
Solar Cells," Sayak Bhattacharya, Ibrahim Baydoun, Mi Lin and Sajeev John, Physical Review Applied, 11, 014005 (2019)
- "Broadband light-trapping enhancement of graphene absorptivity," Xiwen Zhang and Sajeev John, Physical Review B, 99, 035417 (2019)
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