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.

News Stories: Toronto Star, Physics Today, Maclean's Magazine, Edge Magazine: Trapping the Light Fantastic CBC National News, Physics Newsletter

Killam Lecture and Interview (MP3 Audio)


Current research: Photonics, Nano-science, Solar energy harvesting, Bio-sensors for Medical Diagnostics, Room Temperature Bose-Einstein Condensation

Electromagnetic and electronic simulation software downloads

Phone: (416) 978-3459 Fax: (416) 978-2537 e-mail: john at


Research Interests and Contributions

Light Localization and Photonic Band Gap Materials

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 Photonic Crystals

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%.

Beyond 30% Conversion Efficiency for Thin-Silicon Solar Cells

Photonic Crystal Light Trapping: The Key to Breaking Photovoltaic Efficiency Barriers

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.

Quantum Optics

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.

Multiple Light Scattering Spectroscopy and Random Lasing

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].

Magnetism and Superconductivity

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

Former Postdocs

  • 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

  • Timothy Chan
  • Artan Kaso
  • Neset Akozbek
  • Mona Berciu
  • Lucia Florescu
  • Marian Florescu
  • Ovidiu Toader
  • Nipun Vats
  • Mesfin Woldeyohannes
  • Chiranjeeb Roy
  • James Bauer
  • Shengjun Yang
  • Xun Ma
  • Pranai Vasudev
  • Stephen Foster
  • Abdullah Al-Rashid

Current Ph.D. Students

  • Kenny Yip

Current Postdocs

  • Sayak Bhattacharya
  • Xiwen Zhang

Selected Publications (Chronological List)

    1984- 1989

  1. "Electromagnetic Absorption in a Disordered Medium near a Photon Mobility Edge", Sajeev John, Phys. Rev. Lett. 53, 2169 (1984). ABSTRACT PDF
  2. "Spin Glass State of a Randomly diluted Granular Superconductor", Sajeev John and T.C. Lubensky, Phys. Rev. Lett. 55, 1014 (1985). ABSTRACT PDF
  3. "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 PDF
  4. "Strong Localization of Photons in Certain Disordered Dielectric Superlattices", Sajeev John, Phys. Rev. Lett. 58, 2486 (1987). ABSTRACT PDF
  5. "Localization and the Density of States for an Electron in a Quantized Elastic Continuum", Sajeev John, Physical Review B 35, 9291 (1987). ABSTRACT PDF
  6. "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 PDF
  7. "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 PDF
  8. 1990 - 1995

  9. ''Localization of Light'', S. John, Physics Today, May (1991), Cover Story.
  10. ''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 PDF
  11. ''Nonlinear Optical Solitary Waves in a Photonic Bandgap'', S. John and N. Akozbek, Physical Review Letters 71, 1168 (1993). ABSTRACT PDF
  12. ''Topological Magnetic Solitons in the Two-Dimensional Mott-Hubbard Gap'', S. John and A. Golubentsev, Physical Review Letters 71, 3343 (1993). ABSTRACT PDF
  13. "Spontaneous Emission near the Edge of a Photonic Bandgap", Sajeev John and Tran Quang, Physical Review A 50 1764 (1994). ABSTRACT PDF
  14. "Spin-flux and Magnetic Solitons in an Interacting Two-Dimensional Electron Gas: Topology of Two-Valued Wavefunctions", Sajeev John and A. Golubentsev, Physical Review B51, 381 (1995). ABSTRACT. PDF
  15. ''Localization of Superradiance near a Photonic Bandgap'', S. John and T. Quang, Phys. Rev. Lett. 74, 3419 (1995). ABSTRACT PDF
  16. 1996 - 1997

  17. ''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
  18. ''Quantum Optical Spin-Glass State of Impurity Two-Level Atoms in a Photonic Bandgap'', S. John and T. Quang, Phys. Rev. Lett. 76, 1320 (1996). ABSTRACT PDF
  19. ''Resonant Nonlinear Dielectric Response in a Photonic Band Gap Material'', S. John and T. Quang, Phys. Rev. Lett. 76, 2484 (1996). ABSTRACT PDF
  20. ''Theory of Lasing in a Multiple Scattering Medium'', S. John and G. Pang, Physical Review A 54, 3642 (1996). ABSTRACT PDF
  21. "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 PDF POSTSCRIPT
  22. "Multiphoton Localization and Propagating Quantum Gap Solitons in a Frequency Gap Medium", Sajeev John and Valery Rupasov, Physical Review Letters 79, 821 (1997). ABSTRACT PDF POSTSCRIPT
  23. "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). ABSTRACT PDF POSTSCRIPT
  24. "Frozen Light", Sajeev John, Nature 390, 661 (1997). PDF
  25. 1998 - 2000

  26. "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 PDF POSTSCRIPT
  27. "Midgap States of a Two-Dimensional Antiferromagnetic Mott Insulator: Electronic Structure of Meron-Vortices", Sajeev John, Mona Berciu and A. Golubentsev, Europhysics Letters 41 (1), 31 (1998). ABSTRACT PDF
  28. "Photonic Band Gap Formation in Certain Self-Organizing Systems", Kurt Busch and Sajeev John, Physical Review E 58, 3896 (1998). ABSTRACT PDF POSTSCRIPT
  29. "Liquid Crystal Photonic Band Gap Materials: The Tunable Electromagnetic Vacuum", Kurt Busch and Sajeev John, Physical Review Letters 83 (5), 967-970 (1999). ABSTRACT PDF POSTSCRIPT
  30. "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 PDF POSTSCRIPT
  31. "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 PDF
  33. "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 PDF
  35. "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 (2000). ABSTRACT PDF
  36. 2001 - 2003

  37. "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
  38. "Proposed Square Spiral Microfabrication Architecture for Large Three-Dimensional Photonic Band Crystals", Ovidiu Toader and Sajeev John, Science vol. 292, 1133 (2001).   ABSTRACT   PDF
  39. "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
  40. "Theory of Fluorescence in Photonic Crystals", Nipun Vats, K. Busch, Sajeev John, Physical Review A 65, 043808 (2002). ABSTRACT   PDF  POSTSCRIPT
  41. "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
  42. "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
  43. "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
  44. "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
  45. 2004 - 2005

  46. "Photonic Band Gap Synthesis by Holographic Lithography" Ovidiu Toader, Tim Chan, and Sajeev John, Physical Review Letters 92, 043905 (2004). ABSTRACT  PDF POSTSCRIPT
  47. "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  PDF  POSTSCRIPT
  48. "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
  49. "Photonic band gap enhancement in frequency-dependent dielectrics", Ovidiu Toader and Sajeev John, Physical Review E 70, 046605 (2004). ABSTRACT PDF
  50. "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  PDF
  51. "Magnetic structure factor in cuprate superconductors: Evidence for charged meron vortices", Mona Berciu and Sajeev John, Physical Review B 69, 224515 (2004). ABSTRACT PDF
  52. "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
  53. 2005 - 2006

  54. "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
  55. "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
  56. "Slanted Pore Photonic Band Gap Materials", Ovidiu Toader and Sajeev John, Physical Review E 71, 036605 (2005). ABSTRACT  PDF
  57. "Light Localization for Broadband Integrated Optics in Three Dimensions", A. Chutinan and Sajeev John, Physical Review B 72, 16, 161316 (2005). ABSTRACT PDF
  58. "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
  59. "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
  60. "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
  61. "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, (2006). ABSTRACT  PDF
  62. "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
  63. "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
  64. ''Nonlinear Bloch waves in resonantly doped photonic crystals'', Artan Kaso and Sajeev John, Physical Review E 74, 046611 (2006) ABSTRACT  PDF
  65. "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
  66. "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
  67. 2007 - 2009

  68. "Electromagnetically Induced Exciton Mobility in a Photonic Band Gap", Sajeev John and Shengjun Yang, Physical Review Lett. 99 , 046801 (2007).   ABSTRACT PDF
  69. "Exciton dressing and capture by a photonic band edge", Shengjun Yang and Sajeev John, Physical Review B 75, 235332 (2007).   ABSTRACT PDF
  70. "Molding light flow from photonic band gap circuits to microstructured fibers", James Bauer and Sajeev John, Applied Physics Letters 90, 261111 (2007).   ABSTRACT PDF
  71. "Nonlinear Bloch waves in metallic photonic band-gap filaments", Artan Kaso and Sajeev John, Physical Review A 76, 053838 (2007). ABSTRACT PDF
  72. "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).  ABSTRACT PDF
  73. "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
  74. "Compact optical one-way waveguide isolators for photonic-band-gap microchips", Hiroyuki Takeda and Sajeev John, Physical Review A 78, 023804 (2008)   ABSTRACT PDF
  75. "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
  76. "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
  77. "Circuits for light in holographically defined photonic-band-gap materials", Timothy Y. M. Chan and Sajeev John, Physical Review A 78, 033812 (2008).   ABSTRACT  PDF
  78. "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  PDF
  79. "Metallic photonic-band-gap filament architectures for optimized incandescent lighting", Sajeev John and Rongzhou Wang, Physical Review A, 78, 043809 (2008).  ABSTRACT  PDF
  80. "Optical wavelength converters for photonic band gap microcircuits", Dragan Vujic and Sajeev John, Physical Review A 79, 053836 (2009). ABSTRACT  PDF
  81. "Ultrafast Population Switching of Quantum Dots in a Structured Vacuum", Xun Ma and Sajeev John, Physical Review Lett. 103, 233601 (2009). ABSTRACT  PDF
  82. "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
  83. 2010 - 2012

  84. "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
  85. "Self-consistent Maxwell-Bloch theory of quantum-dot-population switching in photonic crystals", Hiroyuki Takeda and Sajeev John, Physical Review A 83, 053811 (2011). ABSTRACT  PDF
  86. "Coherence and antibunching in a trapped interacting Bose-Einstein condensate", Shengjun Yang and Sajeev John, Physical Review B 84, 024515 (2011). ABSTRACT  PDF
  87. "Quantum-dot all-optical logic in a structured vacuum", Xun Ma and Sajeev John, Physical Review A 84, 013830 (2011). ABSTRACT  PDF
  88. "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
  89. "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
  90. "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). ABSTRACT  PDF
  91. "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). ABSTRACT  PDF
  92. "Solar energy trapping with modulated silicon nanowire photonic crystals", Guillaume Demesy and Sajeev John, J. Appl. Phys., 112, 074326 (2012). ABSTRACT  PDF
  93. "Solar power conversion efficiency in modulated silicon nanowire photonic crystals", Alexei Deinega and Sajeev John, J. Appl. Phys. 112, 074327 (2012). ABSTRACT  PDF
  94. 2013 - 2014

  95. "Light-trapping in dye-sensitized solar cells", Stephen Foster and Sajeev John, Energy Environ. Sci., DOI: 10.1039/C3EE40185E (2013). ABSTRACT  PDF
  96. "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. ABSTRACT  PDF
  97. "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  PDF
  98. "Resonant dipole-dipole interaction in confined and strong-coupling dielectric geometries", Ramy El-Ganainy and Sajeev John, New Journal of Physics, 15, 083033 (2013). ABSTRACT  PDF
  99. "Macroscopic response in active nonlinear photonic crystals", Gandhi Alagappan,Sajeev John, and Er Ping Li, Optics Letters 38, No. 18, 3514 (2013). ABSTRACT  PDF
  100. "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). ABSTRACT  PDF
  101. "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). ABSTRACT  PDF
  102. "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). ABSTRACT  PDF
  103. "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). ABSTRACT  PDF
  104. "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). ABSTRACT  PDF
  105. "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). ABSTRACT  PDF  Supplementary Information
  106. 2015 - 2017

  107. "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). ABSTRACT  PDF
  108. "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). ABSTRACT  PDF
  109. "Waveguide-mode polarization gaps in square spiral photonic crystals," Rong-Juan Liu, Sajeev John and Zhi-Yuan Li, EPL, 111 54001 (2015). ABSTRACT  PDF
  110. "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). ABSTRACT  PDF
  111. "Light-trapping in perovskite solar cells," Qing Guo Du, Guansheng Shen and Sajeev John, AIP Advances 6, 065002 (2016). ABSTRACT  PDF
  112. "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  PDF
  113. "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  PDF
  114. "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  PDF
  115. "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  PDF
  116. "Light-trapping design for thin-film silicon-perovskite tandem solar cells," Stephen Foster and Sajeev John, Journal of Applied Physics 120, 103103 (2016). ABSTRACT  PDF
  117. "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). ABSTRACT  PDF
  118. "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). ABSTRACT  PDF
  119. 2018 - Present

  120. "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). ABSTRACT  PDF
  121. "Designing High-Efficiency Thin Silicon Solar Cells Using Parabolic-Pore Photonic Crystals," Sayak Bhattacharya and Sajeev John, Physical Review Applied 9, 044009 (2018). ABSTRACT  PDF
  122. "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
  123. "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). ABSTRACT  PDF
  124. "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) ABSTRACT  PDF
  125. "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) ABSTRACT  PDF
  126. "Broadband light-trapping enhancement of graphene absorptivity," Xiwen Zhang and Sajeev John, Physical Review B, 99, 035417 (2019) ABSTRACT  PDF

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