All Stories

  1. Characteristics of ultrafast response induced by impulsive interference of excitons in a GaAs/AlAs multiple quantum well on a slightly strained buffer layer

    Article • Applied Physics Express, June 2023, Institute of Physics Publishing

    Osamu Kojima

  2. Generation of nonlinear polarization to emit terahertz waves in above gap states in GaSb/AlGaSb multiple quantum wells

    Article • Applied Physics Express, May 2023, Institute of Physics Publishing

    Osamu Kojima

  3. Increase in terahertz-wave intensity in a magnetic field due to difference-frequency mixing by exciton excitation in a GaAs/AlAs multiple quantum well

    Article • Optics Express, March 2022, Optical Society of America (OSA)

    Osamu Kojima

  4. Increase in terahertz-wave generation by difference frequency mixing by the overlap of exciton states in different GaAs/AlAs quantum wells and spectroscopic measurements

    Article • Optics Express, July 2021, Optical Society of America (OSA)

    Osamu Kojima

  5. Modulation of exciton states through resonant excitation by continuous wave lasers in a GaAs/AlAs multiple quantum well

    Article • Journal of Physics D Applied Physics, June 2021, Institute of Physics Publishing

    Osamu Kojima

  6. Photoluminescence excitation spectroscopy for structural and electronic characterization of resonant tunneling diodes for THz applications

    Article • AIP Advances, March 2021, American Institute of Physics

    michele cito, Osamu Kojima

  7. Resonant exciton excitation photoluminescence and dynamics in a GaAs/AlAs multiple quantum well with internal electric field

    Article • AIP Advances, September 2020, American Institute of Physics

    Osamu Kojima

  8. Electron transport in a silicon crystal observed by energy transfer luminescence

    Article • Japanese Journal of Applied Physics, July 2020, Institute of Physics Publishing

    Osamu Kojima

  9. Exciton dynamics as a function of excitation intensity and double-pulse excitation in cyanine molecule thin films: Toward low-power optical switches

    Article • Journal of Applied Physics, July 2019, American Institute of Physics

    Osamu Kojima

  10. Effect of modulation of ultrafast transient carrier dynamics by interface on terahertz signal

    Article • Journal of Physics Conference Series, May 2019, Institute of Physics Publishing

    Osamu Kojima

  11. Effects of a thin nitrogen-doped layer on terahertz dynamics in GaAs containing InAs quantum dots

    Article • OSA Continuum, April 2019, Optical Society of America (OSA)

    Osamu Kojima

  12. Broadband THz absorption spectrometer based on excitonic nonlinear optical effects

    Article • Light Science & Applications, March 2019, Springer Science + Business Media

    Osamu Kojima

  13. Wide Frequency Tuning of Continuous Terahertz Wave Generated by Difference Frequency Mixing under Exciton-Excitation Conditions in a GaAs / AlAs Multiple Quantum Well

    Article • Physical Review Applied, October 2018, American Physical Society (APS)

    Osamu Kojima

  14. Effect of lattice-mismatch strain on electron dynamics in InAs/GaAs quantum dots as seen by time-domain terahertz spectroscopy

    Article • Journal of Physics D Applied Physics, July 2018, Institute of Physics Publishing

    Osamu Kojima

  15. Excitation of Thin Cyanine Films via Energy Transfer from Si Substrate

    Article • Journal of the Physical Society of Japan, September 2017, Physical Society of Japan

    Osamu Kojima

  16. Effects of exciton line widths on the amplitude of quantum beat oscillations

    Article • Applied Physics Express, May 2016, Institute of Physics Publishing

    Osamu Kojima

  17. Fabrication of cyanine dye thin films grown by a layer-by-layer method

    Article • Materials Research Express, July 2015, Institute of Physics Publishing

    Osamu Kojima

  18. Rapid dephasing related to intersubband transitions induced by exciton quantum beats observed by a pump-probe technique in a GaAs/AlAs multiple quantum well

    Article • Physical Review B, March 2015, American Physical Society (APS)

    Osamu Kojima

  19. Effect of exciton oscillator strength on upconversion photoluminescence in GaAs/AlAs multiple quantum wells

    Article • Applied Physics Letters, November 2014, American Institute of Physics

    Osamu Kojima

  20. Control of optical properties in cyanine dye thin film fabricated by a layer-by-layer method

    Article • Journal of Applied Physics, February 2014, American Institute of Physics

    Osamu Kojima

  21. Pulse modulation towards low-power operation based on the quantum beat of excitons in a GaAs/AlAs multiple quantum well

    Article • Journal of Physics D Applied Physics, February 2014, Institute of Physics Publishing

    Osamu Kojima

  22. Effects of pumping on propagation velocities of confined exciton polaritons in GaAs/AlxGa1−xAs double heterostructure thin films under resonant and non-resonant probe conditions

    Article • Journal of Applied Physics, January 2013, American Institute of Physics

    Osamu Kojima

  23. Enhancement of Optical Anisotropy by Interconnection Effect along Growth Direction in Multistacked Quantum Dots

    Article • Japanese Journal of Applied Physics, January 2013, Institute of Physics Publishing

    Osamu Kojima

  24. Quantum beats of type-I and type-II excitons in an InxGa1−xAs/GaAs strained single quantum well

    Article • Journal of Applied Physics, August 2012, American Institute of Physics

    Osamu Kojima

  25. Observation of quantum beat oscillations and ultrafast relaxation of excitons confined in GaAs thin films by controlling probe laser pulses

    Article • Journal of Applied Physics, January 2012, American Institute of Physics

    Osamu Kojima

  26. Dynamics of above-barrier state excitons in multi-stacked quantum dots

    Article • Journal of Applied Physics, November 2011, American Institute of Physics

    Osamu Kojima

  27. Saturation of Förster resonance energy transfer between two optically nonlinear cyanine dyes of small Stokes shift energies in polymer thin films

    Article • Journal of Applied Physics, October 2011, American Institute of Physics

    Osamu Kojima

  28. Extremely uniform bound exciton states in nitrogen δ-doped GaAs studied by photoluminescence spectroscopy in external magnetic fields

    Article • Journal of Applied Physics, October 2011, American Institute of Physics

    Osamu Kojima

  29. Depolarization effect on optical control of exciton states confined in GaAs thin films

    Article • Journal of Applied Physics, August 2011, American Institute of Physics

    Osamu Kojima

  30. Observation of phase shifts in a vertical cavity quantum dot switch

    Article • Applied Physics Letters, June 2011, American Institute of Physics

    Chaoyuan Jin, Osamu Kojima

  31. Dephasing of Excitonic Polaritons Confined in GaAs Thin Films

    Article • Journal of the Physical Society of Japan, March 2011, Physical Society of Japan

    Osamu Kojima

  32. Intraband relaxation process in highly stacked quantum dots

    Article • physica status solidi c, December 2010, Wiley

    Osamu Kojima

  33. Excitation power dependence of nonlinear optical response of excitons in GaAs/AlAs superlattices

    Article • physica status solidi c, December 2010, Wiley

    Osamu Kojima

  34. Interaction between conduction-band edge and nitrogen-related localized levels in nitrogen δ -doped GaAs

    Article • physica status solidi c, November 2010, Wiley

    Osamu Kojima

  35. Bound biexciton luminescence in nitrogen δ-doped GaAs

    Article • physica status solidi (b), November 2010, Wiley

    Osamu Kojima

  36. Propagation velocity of excitonic polaritons confined in GaAs thin films

    Article • physica status solidi c, November 2010, Wiley

    Osamu Kojima

  37. Detailed Design and Characterization of All-Optical Switches Based on InAs/GaAs Quantum Dots in a Vertical Cavity

    Article • IEEE Journal of Quantum Electronics, November 2010, Institute of Electrical & Electronics Engineers (IEEE)

    Chaoyuan Jin, Osamu Kojima

  38. Temperature-dependent carrier tunneling for self-assembled InAs/GaAs quantum dots with a GaAsN quantum well injector

    Article • Applied Physics Letters, April 2010, American Institute of Physics

    Chaoyuan Jin, Osamu Kojima

  39. Temperature dependence of photoluminescence characteristics of excitons in stacked quantum dots and quantum dot chains

    Article • Journal of Applied Physics, April 2010, American Institute of Physics

    Osamu Kojima

  40. Vertical-geometry all-optical switches based on InAs/GaAs quantum dots in a cavity

    Article • Applied Physics Letters, July 2009, American Institute of Physics

    Chaoyuan Jin, Osamu Kojima

  41. Optical Kerr response to multi pump pulses on GaAs weakly confined exciton

    Article • physica status solidi c, June 2009, Wiley

    Osamu Kojima

  42. Transient reflectivity response with negative time delay caused by femtosecond pulse propagation in GaAs thin films

    Article • physica status solidi c, April 2009, Wiley

    Osamu Kojima

  43. Exciton response controlled by introducing a spacer layer in nitrided InAs quantum dots

    Article • physica status solidi c, April 2009, Wiley

    Osamu Kojima

  44. Effects of indium segregation on optical properties of nitrogen-doped InAs/GaAs quantum dots

    Article • Journal of Applied Physics, November 2008, American Institute of Physics

    Osamu Kojima

  45. Ultrafast All-Optical Control of Excitons Confined in GaAs Thin Films

    Article • Applied Physics Express, November 2008, Institute of Physics Publishing

    Osamu Kojima

  46. Spectral width dependence of residual carrier effect on nonlinear optical response of weakly confined excitons

    Article • physica status solidi c, July 2008, Wiley

    Osamu Kojima

  47. Photoluminescence characteristics of quantum dots with electronic states interconnected along growth direction

    Article • Journal of Applied Physics, June 2008, American Institute of Physics

    Osamu Kojima

  48. Decay of orientational grating of weakly confined excitons in GaAs thin films

    Article • Journal of Luminescence, May 2008, Elsevier

    Osamu Kojima

  49. Effects of excitation spectral width on decay profile of weakly confined excitons

    Article • Journal of Luminescence, May 2008, Elsevier

    Osamu Kojima

  50. Photoluminescence dynamics of coupled quantum dots

    Article • Journal of Luminescence, May 2008, Elsevier

    Osamu Kojima

  51. Photoluminescence dynamics of weakly confined excitons in GaAs thin films

    Article • Journal of Luminescence, May 2008, Elsevier

    Osamu Kojima

  52. Ultrafast Response Induced by Interference Effects between Weakly Confined Exciton States

    Article • Journal of the Physical Society of Japan, April 2008, Physical Society of Japan

    Osamu Kojima

  53. Ultrafast optical Kerr effect of excitons weakly confined in GaAs thin films

    Article • physica status solidi c, January 2008, Wiley

    Osamu Kojima

  54. Ultrafast nonlinear optical response of weakly confined excitons in GaAs thin films

    Article • physica status solidi c, April 2007, Wiley

    Osamu Kojima

  55. Enhancement of nonlinear optical response of weakly confined excitons in GaAs thin films by spectrally rectangle-shape-pulse-excitation

    Article • Journal of Physics Conference Series, March 2007, Institute of Physics Publishing

    Osamu Kojima

  56. Terahertz radiation from coherent confined optical phonons in GaAs/AlAs multiple quantum wells

    Article • physica status solidi (a), February 2007, Wiley

    Osamu Kojima

  57. Spectrally resolved nonlinear optical response of weakly confined excitons under femtosecond laser pulse excitation in GaAs thin films

    Article • physica status solidi c, March 2006, Wiley

    Osamu Kojima

  58. Intense terahertz radiation from longitudinal optical phonons in GaAs∕AlAs multiple quantum wells

    Article • Applied Physics Letters, August 2005, American Institute of Physics

    Osamu Kojima

  59. Characteristics of coupled mode of excitonic quantum beat and coherent longitudinal optical phonon in GaAs/AlAs multiple quantum wells

    Article • Journal of Luminescence, April 2005, Elsevier

    Osamu Kojima

  60. Intense coherent longitudinal optical phonons in CuI thin films under exciton–excitation conditions

    Article • Journal of Luminescence, April 2005, Elsevier

    Osamu Kojima

  61. Enhancement of coherent longitudinal optical phonon oscillations in aGaAs∕AlAsmultiple quantum well due to intersubband energy tuning under an electric field

    Article • Physical Review B, December 2004, American Physical Society (APS)

    Osamu Kojima

  62. Coupled mode of the coherent optical phonon and excitonic quantum beat in GaAs∕AlAs multiple quantum wells

    Article • Physical Review B, June 2004, American Physical Society (APS)

    Osamu Kojima

  63. Enhancement of coherent LO phonons by quantum beats of excitons in GaAs/AlAs multiple quantum wells

    Article • Journal of Luminescence, June 2004, Elsevier

    Osamu Kojima

  64. Coupling of coherent longitudinal optical phonons to excitonic quantum beats in GaAs/AlAs multiple quantum wells

    Article • October 2003, American Physical Society (APS)

    Osamu Kojima

  65. Thermal-strain-induced splitting of heavy- and light-hole exciton energies in CuI thin films grown by vacuum evaporation

    Article • November 1999, American Physical Society (APS)

    Osamu Kojima