Journal Papers

54. Excitation of thin cyanine films via energy transfer from Si substrate
Y. Ito, O. Kojima, T. Kita, Y. Shim
Journal of the Physical Society of Japan 86, 094710-1-4 (2017).

53. Effects of non-exciton components excited by broadband pulses on quantum beats in a GaAs/AlAs multiple quantum well
O. Kojima, Y. Iwasaki, T. Kita, K. Akahane
Scientific Reports 7, 41496-1-7 (2017). download from Kobe University Repository

2016

52. Increase in exciton decay rate due to plane-to-plane interaction between cyanine thin films
J. Nagauchi, O. Kojima, T. Kita, Y. Shim
AIP Advances 6, 075209-1-7 (2016). download from Kobe University Repository

51. Effects of exciton line widths on the amplitude of quantum beat oscillations
O. Kojima, T. Kita
Applied Physics Express 9, 062801-1-3 (2016). download from Kobe University Repository

2015

50. Fabrication of cyanine dye thin films grown by a layer-by-layer method
J. Nagauchi, O. Kojima, T. Kita, Y. Shim
Material Research Express 2, 076402-1-7 (2015). download from Kobe University Repository

49. Rapid dephasing related to intersubband transitions induced by exciton quantum beats observed by a pump-probe technique in a GaAs/AlAs multiple quantum well
O. Kojima, K. Kojima, T. Kita, K. Akahane
Physical Review B 91, 125307-1-4 (2015). download from Kobe University Repository

2014

48. Effect of exciton oscillator strength on upconversion photoluminescence in GaAs/AlAs multiple quantum wells
O. Kojima, S. Okumura, T. Kita, K. Akahane
Applied Physics Letters 105, 181901-1-3 (2014). download from Kobe University Repository

47. Control of optical properties in cyanine dye thin film fabricated by a layer-by-layer method
O. Kojima, R. Fujii, T. Kita, Y. Shim
Journal of Applied Physics 115, 083503-1-4 (2014). download from Kobe University Repository

46. Pulse modulation towards low-power operation based on the quantum beat of excitons in a GaAs/AlAs multiple quantum well
O. Kojima, K. Hayashii, T. Kita, K. Akahane
Journal of Physics D: Applied Physics 47, 105101-1-5 (2014). download from Kobe University Repository

2013

2012

43. Quantum beats of type-I and type-II excitons in an InxGa1−xAs/GaAs strained single quantum well
O. Kojima, K. Mizoguchi, M. Nakayama
Journal of Applied Physics 112, 043522-1-4 (2012). download from Kobe University Repository

42. Observation of quantum beat oscillations and ultrafast relaxation of excitons confined in GaAs thin films by controlling probe laser pulses
S. Ohta, O. Kojima, T. Kita, T. Isu
Journal of Applied Physics 111, 023505-1-4 (2012). download from Kobe University Repository

2011

41. Dynamics of above-barrier state excitons in multi-stacked quantum dots
O. Kojima, N. Tobita, T. Kita, K. Akahane
Journal of Applied Physics 110, 093515-1-4 (2011). download from Kobe University Repository

40. Extremely uniform bound exciton states in nitrogen d-doped GaAs studied by photoluminescence spectroscopy in external magnetic fields
Y. Harada, T. Kubo, T. Inoue, O. Kojima, T. Kita
Journal of Applied Physics 110, 083522 (2011). download from Kobe University Repository

39. Saturation of Förster resonance energy transfer between two optically nonlinear cyanine dyes of small Stokes shift energies in polymer thin films
O. Kojima, S. Hamano, T. Kita, O. Wada
Journal of Applied Physics 110, 083521-1-5 (2011). download from Kobe University Repository

38. Depolarization effect on optical control of exciton states confined in GaAs thin films
T. Yamashita, O. Kojima, T. Kita, T. Isu
Journal of Applied Physics 110, 043514-1-5 (2011). download from Kobe University Repository

37. Observation of phase shifts in a vertical cavity quantum dot switch
C. Jin, O. Kojima, T. Kita, O. Wada, M. Hopkinson
Applied Physics Letters 98, 231101 (2011).

36. Dephasing of excitonic polaritons confined in GaAs thin films
O. Kojima, S. Watanabe, T. Kita, O. Wada, T. Isu
Journal of Physical Society of Japan 80, 034704 (2011).

35. Propagation velocity of excitonic polaritons confined in GaAs thin films
O. Kojima, S. Watanabe, T. Kita, O. Wada, T. Isu
Physica Status Solidi C 8, pp. 378-380 (2011).

34. Interaction between conduction-band edge and nitrogen-related localized levels in nitrogen d-doped GaAs
Y. Harada, O. Kojima, T. Kita, O. Wada
Physica Status Solidi C 8, pp. 365-367 (2011).

33. Bound biexciton luminescence in nitrogen d-doped GaAs
Y. Harada, O. Kojima, T. Kita, O. Wada
Physica Status Solidi B 248, pp. 464-467 (2011).

32. Excitation power dependence of nonlinear optical response of excitons in GaAs/AlAs superlattices
T. Yamashita, O. Kojima, T. Kita, O. Wada, K. Akahane
Physica Status Solidi C 8, pp. 50-53 (2011).

31. Intraband relaxation process in highly stacked quantum dots
O. Kojima, M. Mamizuka, T. Kita, O. Wada, K. Akahane
Physica Status Solidi C 8, pp. 46-49 (2011).

2010

30. Detailed design and characterization of all-optical switches based on InAs/GaAs quantum dots in a vertical cavity
C. Jin, O. Kojima, T. Inoue, T. Kita, O. Wada, M. Hopkinson, K. Akahane
IEEE Journal of Quantum Electronics 46, pp. 1582-1589 (2010).

29. Temperature-dependent carrier tunneling for self-assembled InAs/GaAs quantum dots with a GaAsN quantum well injector
C. Jin, S. Ohta, M. Hopkinson, O. Kojima, T. Kita, O. Wada
Applied Physics Letters 96, 151104 (2010).

28. Temperature dependence of photoluminescence characteristics of excitons in stacked quantum dots and quantum dot chains
O. Kojima, H. Nakatani, T. Kita, O. Wada, K. Akahane
Journal of Applied Physics 107, 073506 (2010).

2009

27. Vertical-geometry all-optical switches based on InAs/GaAs quantum dots in a cavity
C. Jin, O. Kojima, T. Kita, O. Wada, M. Hopkinson, K. Akahane
Applied Physics Letters 95, pp. 021109 (2009).

26. Optical Kerr response to multi pump pulses on GaAs weakly confined exciton
A. Kanno, R. Katouf, O. Kojima, J. Ishi-Hayase, M. Tsuchiya, T. Isu
physica status solidi (c) 6, pp.1509-1512 (2009).

25. Exciton response controlled by introducing a spacer layer in nitrided InAs quantum dots
M. Mamizuka, O. Kojima, T. Inoue, T. Kita, O. Wada
physica status solidi (c) 6, pp. S146-S149 (2009).

24. Transient reflectivity response with negative time delay caused by femtosecond pulse propagation in GaAs thin films
S. Watanabe, O. Kojima, T. Kita, O. Wada, T. Isu
physica status solidi (c) 6, pp. S139-S142 (2009).

2008

23. Effects of indium segregation on optical properties of nitrogen-doped InAs/GaAs quantum dots
T. Inoue, M. Mamizuka, H. Mizuno, O. Kojima, T. Kita, O. Wada
Journal of Applied Physics 104, 103532 (2008).

22. Ultrafast All-Optical Control of Excitons Confined in GaAs Thin Films
O. Kojima, A. Miyagawa, T. Kita, O. Wada, T. Isu
Applied Physics Express 1, 112401 (2008).

21. Photoluminescence characteristics of quantum dots with electronic states interconnected along growth direction
O. Kojima, H. Nakatani, T. Kita, O. Wada, K. Akahane, M. Tsuchiya
Journal of Applied Physics 103, 113504 (2008).

20. Spectral width dependence of residual carrier effect on nonlinear optical response of weakly confined excitons
O. Kojima, T. Isu, J. Ishi-Hayase, A. Kanno, R. Katouf, M. Sasaki, M. Tsuchiya
physica status solidi (c) 5, pp. 2858-2860 (2008).

19. Ultrafast response induced by interference effects between weakly confined exciton states
O. Kojima, T. Isu, J. Ishi-Hayase, A. Kanno, R. Katouf, M.Sasaki, M. Tsuchiya
Journal of the Physical Society of Japan 77, 044701 (2008).

18. Photoluminescence dynamics of weakly confined excitons in GaAs thin films
A. Kanno, R. Katouf, O. Kojima, J. Ishi-Hayase, M.Sasaki, M. Tsuchiya, T. Isu
Journal of Luminescence 128, pp. 1069-1071 (2008).

17. Photoluminescence dynamics of coupled quantum dots
H. Nakatani, T. Kita, O. Kojima, O. Wada, K. Akahane, M. Tsuchiya
Journal of Luminescence 128, pp. 975-977 (2008).

16. Effects of excitation spectral width on decay profile of weakly confined excitons
O. Kojima, T. Isu, J. Ishi-Hayase, A. Kanno, R. Katouf, M.Sasaki, M. Tsuchiya
Journal of Luminescence 128, pp. 966-968 (2008).

15. Decay of orientational grating of weakly confined excitons in GaAs thin films
O. Kojima, T. Isu, J. Ishi-Hayase, A. Kanno, R. Katouf, M.Sasaki, M. Tsuchiya
Journal of Luminescence 128, pp. 963-965 (2008).

14. Ultrafast optical Kerr effect of excitons weakly confined in GaAs thin films
A. Kanno, R. Katouf, O. Kojima, J. Ishi-Hayase, M. Tsuchiya, T. Isu
physica status solidi (c) 5, pp. 360-363 (2008)

2007

13. Enhancement of nonlinear optical response of weakly confined excitons in GaAs thin films by spectrally rectangle-shape-pulse-excitation
O. Kojima, T. Isu, J. Ishi-Hayase, M.Sasaki, M. Tsuchiya
Journal of Physics: Conference Series 61, pp. 618-622 (2007).

12. Ultrafast nonlinear optical response of weakly confined excitons in GaAs thin films
O. Kojima, T. Isu, J. Ishi-Hayase, M.Sasaki, M. Tsuchiya
physica status solidi (c) 4, pp. 1731-1734 (2007).

11. Terahertz radiation from coherent confined optical phonons in GaAs/AlAs multiple quantum wells
M. Nakayama, K. Mizoguchi, O. Kojima, T. Furuichi, A. Mizumoto, S. Saito, A. Syouji, K. Sakai
physica status solidi (a) 204, pp. 518-521 (2007).

2006

10. 半導体多重量子井戸構造における励起子量子ビートと光学フォノンとの相互作用
中山正昭, 溝口幸司, 小島磨
固体物理 41, pp. 257-267 (2006).

9. Spectrally resolved nonlinear optical response of weakly confined excitons under femtosecond laser pulse excitation in GaAs thin films
O. Kojima, T. Isu, J. Ishi-Hayase, M. Tsuchiya
physica status solidi (c) 3, pp. 675-678 (2006).

2005

8. Intense terahertz radiation from longitudinal optical phonons in GaAs/AlAs multiple quantum wells
K. Mizoguchi, T. Furuichi, O. Kojima, M. Nakayama, S. Saito, A. Syouji, K. Sakai
Applied Physics Letters 87, pp. 093102 (2005).

7. Characteristics of coupled mode of excitonic quantum beat and coherent longitudinal optical phonon in GaAs/AlAs multiple quantum wells
T. Furuichi, K. Mizoguchi, O. Kojima, K. Akahane, N. Yamamoto, N. Ohtani, M. Nakayama
Journal of Luminescence 112, pp. 142-145 (2005).

6. Intense coherent longitudinal optical phonons in CuI thin films under exciton-excitation conditions
O. Kojima, K. Mizoguchi, M. Nakayama
Journal of Luminescence 112, pp. 80-83 (2005).

2004

5. Enhancement of coherent longitudinal optical phonon oscillations in a GaAs/AlAs multiple quantum well due to intersubband energy tuning under an electric field
O. Kojima, K. Mizoguchi, M. Nakayama
Physical Review B 70, 233306 (2004).

4. Coupled mode of the coherent optical phonon and excitonic quantum beat in GaAs/AlAs multiple quantum wells
K. Mizoguchi, O. Kojima, T. Furuichi, M. Nakayama, K. Akahane, N. Yamamoto, N. Ohtani
Physical Review B 69, 233302 (2004).

3. Enhancement of coherent LO phonons by quantum beats of excitons in GaAs/AlAs multiple quantum wells
O. Kojima, K. Mizoguchi, M. Nakayama
Journal of Luminescence 108, pp. 195-199 (2004).

2003

2. Coupling of coherent longitudinal optical phonons to excitonic quantum beats in GaAs/AlAs multiple quantum wells
O. Kojima, K. Mizoguchi, M. Nakayama
Physical Review B 68, 155325 (2003).

1999

1. Thermal-strain-induced splitting of heavy- and light-hole exciton energies in CuI thin films grown by vacuum evaporation
D. Kim, M. Nakayama, O. Kojima, I. Tanaka, H. Ichida, T. Nakanishi, H. Nishimura
Physical Review B 60, pp. 13879-13884 (1999).