Abstract

A novel rewritable optical disk that uses an optical recording material made of naphthalocyanine and polythiophene as the recording layer is described. In this system the complex refractive index of the recording material changes reversibly, depending on the aggregation states of naphthalocyanine induced by a conformation change of the polythiophene matrix. After recording, the imaginary part of the refractive index of the recording material increases to three times that of the unrecorded part, at a wavelength of 790 nm at which a semiconductor laser emits light. The fabricated polythiophene naphthalocyanine optical disk shows a high reflectivity of 58% and a large readout modulation amplitude (I 11/I top) of 0.63. It is confirmed that the polythiophene/aphthalocyanine optical disk can be played back on conventional compact-disc players even after ten cycles of rewriting.

© 1995 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. H. Oba, M. Abe, M. Umehara, T. Sato, Y. Ueda, M. Kunikane, “Organic dye materials for optical recording media,” Appl. Opt. 25, 4023–4026 (1986).
    [CrossRef] [PubMed]
  2. M. C. Gupta, F. Strome, “Erasable laser recording in an organic dye-binder optical disk medium,” J. Appl. Phys. 60, 2932–2937 (1986).
    [CrossRef]
  3. A. H. Sporer, “Reversible laser marking process in anthraqui-none dye films,” Appl. Opt. 26, 1240–1245 (1987).
    [CrossRef] [PubMed]
  4. M. A. Lind, J. S. Hartman, “Performance of a reversible dye–polymer optical recording medium,” in Optical Storage Technology and Applications, D. B. Carlin, A. A. Jamberdino, Y. Tsunoda, eds., Proc. Soc. Photo-Opt. Instrum. Eng.899, 211–218 (1988).
  5. E. Hamada, Y. Shin, T. Ishiguro, “CD-compatible write-once disc with high reflectivity,” in Optical Data Storage Topical Meeting, G. R. Knight, C. N. Kurtz, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1078, 80–87 (1989).
  6. M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
    [CrossRef]
  7. S. Tai, N. Hayashi, “Strong aggregation properties of novel naphthalocyanines,” J. Chem. Soc. Perkin Trans. 2 (August1991), pp. 1275–1279.
    [CrossRef]
  8. K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
    [CrossRef]
  9. K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
    [CrossRef]
  10. I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).
  11. R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).
  12. T. C. Paulick, “Inversion of normal-incidence (R, T) measurements to obtain n + ik for thin films,” Appl. Opt. 25, 562–564 (1986).
    [CrossRef] [PubMed]
  13. T. Fritz, J. Hahn, H. Böttcher, “Determination of the optical constants of evaporated dye layers,” Thin Solid Films 170, 249–257 (1989).
    [CrossRef]
  14. R. D. Bringans, “The determination of the optical constants of thin films from measurements of normal incidence reflectance and transmittance,” J. Phys. D 10, 1855–1861 (1977).
    [CrossRef]
  15. A. Hjortsberg, “Determination of optical constants of absorbing materials using transmission and reflection of thin films on partially metallized substrates: analysis of the new(T, Rm) technique,” Appl. Opt. 20, 1254–1263 (1981).
    [CrossRef] [PubMed]
  16. R. C. McPhedran, L. C. Botten, D. R. McKenzie, R. P. Netterfield, “Unambiguous determination of optical constants of absorbing films by reflectance and transmittance measurements,” Appl. Opt. 23, 1197–1205 (1984).
    [CrossRef] [PubMed]
  17. N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
    [CrossRef]
  18. A. H. M. Holtslag, E. F. McCord, G. H. W. Buning, “Recording mechanism of overcoated metallized dye layers on polycarbonate substrates,” Jpn. J. Appl. Phys. 31, 484–493 (1992).
    [CrossRef]
  19. H. H. Hopkins, “Diffraction theory of laser readout systems for optical video discs,” J. Opt. Soc. Am. 69, 4–24 (1979).
    [CrossRef]

1993 (1)

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

1992 (3)

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

A. H. M. Holtslag, E. F. McCord, G. H. W. Buning, “Recording mechanism of overcoated metallized dye layers on polycarbonate substrates,” Jpn. J. Appl. Phys. 31, 484–493 (1992).
[CrossRef]

1991 (1)

S. Tai, N. Hayashi, “Strong aggregation properties of novel naphthalocyanines,” J. Chem. Soc. Perkin Trans. 2 (August1991), pp. 1275–1279.
[CrossRef]

1989 (1)

T. Fritz, J. Hahn, H. Böttcher, “Determination of the optical constants of evaporated dye layers,” Thin Solid Films 170, 249–257 (1989).
[CrossRef]

1988 (2)

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
[CrossRef]

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
[CrossRef]

1987 (1)

1986 (4)

T. C. Paulick, “Inversion of normal-incidence (R, T) measurements to obtain n + ik for thin films,” Appl. Opt. 25, 562–564 (1986).
[CrossRef] [PubMed]

H. Oba, M. Abe, M. Umehara, T. Sato, Y. Ueda, M. Kunikane, “Organic dye materials for optical recording media,” Appl. Opt. 25, 4023–4026 (1986).
[CrossRef] [PubMed]

M. C. Gupta, F. Strome, “Erasable laser recording in an organic dye-binder optical disk medium,” J. Appl. Phys. 60, 2932–2937 (1986).
[CrossRef]

R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).

1984 (1)

1981 (1)

1979 (1)

1977 (1)

R. D. Bringans, “The determination of the optical constants of thin films from measurements of normal incidence reflectance and transmittance,” J. Phys. D 10, 1855–1861 (1977).
[CrossRef]

Abe, M.

Böttcher, H.

T. Fritz, J. Hahn, H. Böttcher, “Determination of the optical constants of evaporated dye layers,” Thin Solid Films 170, 249–257 (1989).
[CrossRef]

Botten, L. C.

Bringans, R. D.

R. D. Bringans, “The determination of the optical constants of thin films from measurements of normal incidence reflectance and transmittance,” J. Phys. D 10, 1855–1861 (1977).
[CrossRef]

Buning, G. H. W.

A. H. M. Holtslag, E. F. McCord, G. H. W. Buning, “Recording mechanism of overcoated metallized dye layers on polycarbonate substrates,” Jpn. J. Appl. Phys. 31, 484–493 (1992).
[CrossRef]

Fritz, T.

T. Fritz, J. Hahn, H. Böttcher, “Determination of the optical constants of evaporated dye layers,” Thin Solid Films 170, 249–257 (1989).
[CrossRef]

Gu, H. B.

R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).

Gupta, M. C.

M. C. Gupta, F. Strome, “Erasable laser recording in an organic dye-binder optical disk medium,” J. Appl. Phys. 60, 2932–2937 (1986).
[CrossRef]

Habiro, M.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Hagiwara, H.

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

Hahn, J.

T. Fritz, J. Hahn, H. Böttcher, “Determination of the optical constants of evaporated dye layers,” Thin Solid Films 170, 249–257 (1989).
[CrossRef]

Hamada, E.

E. Hamada, Y. Shin, T. Ishiguro, “CD-compatible write-once disc with high reflectivity,” in Optical Data Storage Topical Meeting, G. R. Knight, C. N. Kurtz, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1078, 80–87 (1989).

Hartman, J. S.

M. A. Lind, J. S. Hartman, “Performance of a reversible dye–polymer optical recording medium,” in Optical Storage Technology and Applications, D. B. Carlin, A. A. Jamberdino, Y. Tsunoda, eds., Proc. Soc. Photo-Opt. Instrum. Eng.899, 211–218 (1988).

Hayashi, N.

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

S. Tai, N. Hayashi, “Strong aggregation properties of novel naphthalocyanines,” J. Chem. Soc. Perkin Trans. 2 (August1991), pp. 1275–1279.
[CrossRef]

Hjortsberg, A.

Holtslag, A. H. M.

A. H. M. Holtslag, E. F. McCord, G. H. W. Buning, “Recording mechanism of overcoated metallized dye layers on polycarbonate substrates,” Jpn. J. Appl. Phys. 31, 484–493 (1992).
[CrossRef]

Hopkins, H. H.

Ishiguro, T.

E. Hamada, Y. Shin, T. Ishiguro, “CD-compatible write-once disc with high reflectivity,” in Optical Data Storage Topical Meeting, G. R. Knight, C. N. Kurtz, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1078, 80–87 (1989).

Kamijima, K.

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

Katayose, M.

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

Konishi, K.

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

Kunikane, M.

Kuwano, A.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Lind, M. A.

M. A. Lind, J. S. Hartman, “Performance of a reversible dye–polymer optical recording medium,” in Optical Storage Technology and Applications, D. B. Carlin, A. A. Jamberdino, Y. Tsunoda, eds., Proc. Soc. Photo-Opt. Instrum. Eng.899, 211–218 (1988).

McCord, E. F.

A. H. M. Holtslag, E. F. McCord, G. H. W. Buning, “Recording mechanism of overcoated metallized dye layers on polycarbonate substrates,” Jpn. J. Appl. Phys. 31, 484–493 (1992).
[CrossRef]

McKenzie, D. R.

McPhedran, R. C.

Moritani, K.

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

Nakajima, S.

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
[CrossRef]

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
[CrossRef]

Netterfield, R. P.

Noro, Y.

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

Oba, H.

Park, D. H.

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
[CrossRef]

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
[CrossRef]

Paulick, T. C.

Sato, T.

Shin, Y.

E. Hamada, Y. Shin, T. Ishiguro, “CD-compatible write-once disc with high reflectivity,” in Optical Data Storage Topical Meeting, G. R. Knight, C. N. Kurtz, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1078, 80–87 (1989).

Sporer, A. H.

Strome, F.

M. C. Gupta, F. Strome, “Erasable laser recording in an organic dye-binder optical disk medium,” J. Appl. Phys. 60, 2932–2937 (1986).
[CrossRef]

Sugimoto, R.

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
[CrossRef]

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
[CrossRef]

R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).

Tai, S.

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

S. Tai, N. Hayashi, “Strong aggregation properties of novel naphthalocyanines,” J. Chem. Soc. Perkin Trans. 2 (August1991), pp. 1275–1279.
[CrossRef]

Takane, N.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Takeda, S.

R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).

Taketatsu, J.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Tokushuku, N.

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

Tomiyama, T.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Ueda, Y.

Umehara, M.

Watanabe, I.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Yamada, M.

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

Yanagihara, H.

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

Yoshino, K.

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
[CrossRef]

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
[CrossRef]

R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).

Appl. Opt. (5)

Chem. Express. (1)

R. Sugimoto, S. Takeda, H. B. Gu, K. Yoshino, “Preparation of soluble polythiophene derivatives utilizing transition metal halides as catalysts and their property,” Chem. Express. 1, 635–638 (1986).

Hitachi Chem. Tech. Rep. (1)

I. Watanabe, A. Kuwano, M. Habiro, T. Tomiyama, J. Taketatsu, N. Takane, M. Yamada, “Novel organic optical recording materials using polythiophen and naphthalocyanine,” Hitachi Chem. Tech. Rep. 21, 29–32 (1993).

J. Appl. Phys. (1)

M. C. Gupta, F. Strome, “Erasable laser recording in an organic dye-binder optical disk medium,” J. Appl. Phys. 60, 2932–2937 (1986).
[CrossRef]

J. Chem. Soc. Perkin Trans. 2 (2)

M. Katayose, S. Tai, K. Kamijima, H. Hagiwara, N. Hayashi, “Novel silicon naphthalocyanines: synthesis and molecular arrangement in thin films,” J. Chem. Soc. Perkin Trans. 2 (March1992), pp. 403–409.
[CrossRef]

S. Tai, N. Hayashi, “Strong aggregation properties of novel naphthalocyanines,” J. Chem. Soc. Perkin Trans. 2 (August1991), pp. 1275–1279.
[CrossRef]

J. Opt. Soc. Am. (1)

J. Phys. D (1)

R. D. Bringans, “The determination of the optical constants of thin films from measurements of normal incidence reflectance and transmittance,” J. Phys. D 10, 1855–1861 (1977).
[CrossRef]

Jpn. J. Appl. Phys. (4)

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Spectral change of polymer film containing poly(3-alkylthiophene) with temperature and its application as optical recording madia,” Jpn. J. Appl. Phys. 27, L454–L456 (1988).
[CrossRef]

K. Yoshino, S. Nakajima, D. H. Park, R. Sugimoto, “Thermochromism, photochromism and anomalous temperature dependence of luminescence in poly(3-alkylthiophene) film,” Jpn. J. Appl. Phys. 27, L716–L718 (1988).
[CrossRef]

N. Tokushuku, K. Moritani, H. Yanagihara, K. Konishi, Y. Noro, “High C/N recording in Sb2Se3/Bi write-once disk,” Jpn. J. Appl. Phys. 31, 456–460 (1992).
[CrossRef]

A. H. M. Holtslag, E. F. McCord, G. H. W. Buning, “Recording mechanism of overcoated metallized dye layers on polycarbonate substrates,” Jpn. J. Appl. Phys. 31, 484–493 (1992).
[CrossRef]

Thin Solid Films (1)

T. Fritz, J. Hahn, H. Böttcher, “Determination of the optical constants of evaporated dye layers,” Thin Solid Films 170, 249–257 (1989).
[CrossRef]

Other (2)

M. A. Lind, J. S. Hartman, “Performance of a reversible dye–polymer optical recording medium,” in Optical Storage Technology and Applications, D. B. Carlin, A. A. Jamberdino, Y. Tsunoda, eds., Proc. Soc. Photo-Opt. Instrum. Eng.899, 211–218 (1988).

E. Hamada, Y. Shin, T. Ishiguro, “CD-compatible write-once disc with high reflectivity,” in Optical Data Storage Topical Meeting, G. R. Knight, C. N. Kurtz, eds., Proc. Soc. Photo-Opt. Instrum. Eng.1078, 80–87 (1989).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)

Fig. 1
Fig. 1

Molecular structures of (a) naphthalocyanine and (b) poly-(3-buthylthiophene).

Fig. 2
Fig. 2

Plot of the trajectories of T = 0.782, R = 0.119, Rb = 0.096, and Rmb = 0.696 in the nk plane. The thickness of the film is 75 nm, and the wavelength of the light is 790 nm. The solution is uniquely determined from a cross point, N = 1.82 − i0.09. Rmb negates the other possibility from an approximate cross point N = 0.6 − i0.2.

Fig. 3
Fig. 3

Complex refractive index of naphthalocyanine. The strongest peak of the imaginary part (k) is observed at 830 nm, and the real part (n) shows a strong dispersion in the near-infrared region.

Fig. 4
Fig. 4

Complex refractive index of PBT. The peak of the imaginary part (k) is broad. In the near-infrared wavelength region, the value of k is nearly zero and the value of n is almost constant.

Fig. 5
Fig. 5

Complex refractive indices of the recording layer: (a) unrecorded state, as spin-coated sample; (b) recorded state, after heated at 220 °C and quenched in ice water. At a read and a record laser wavelength of 790 nm, the imaginary part (k) changes to three times the initial value. However, the real part (n) remains almost unchanged.

Fig. 6
Fig. 6

Constructure of the recording medium for the optical simulation. The recording layer consists of Nc dispersed in PBT. The reflective layer is sputtered gold.

Fig. 7
Fig. 7

Calculated contours of reflectivity for the unrecorded state (R unrec) of the optical disk as a function of wavelength and the recording layer thickness.

Fig. 8
Fig. 8

Calculated contours of modulation amplitude as a function of wavelength and the recording layer thickness. Negative contours are omitted to simplify the figure.

Fig. 9
Fig. 9

Dependence of the calculated reflectivity on the recording layer thickness. The solid curve indicates the reflectivity for the unrecorded state (R unrec) and the dashed curve indicates the recorded state (R rec).

Fig. 10
Fig. 10

Calculated substrate-incident reflective spectra of the optical disk: (a) unrecorded part and (b) recorded part.

Fig. 11
Fig. 11

Substrate-incident reflective spectra of the fabricated optical disk measured with a spectrophotometer: (a) unrecorded part, (b) recorded part, and (c) erased part.

Fig. 12
Fig. 12

Series of readout eye-pattern photographs of the EFM signals. (a) After recording. It can be seen that the eyes are clearly open and reflectivities of the recorded parts are decreased symmetrically. The readout modulation amplitudes are 0.63 (I 11/I top) and 0.36 (I 3/I top). Pit jitter (standard deviation of 720-kHz signal) is 23 ns. (b) After erasure, recorded signal traces completely disappear. (c) After five cycles of the rewriting signal, pit jitter of 31 ns is maintained. (d) After ten cycles of the rewriting signal, pit jitter reaches 47 ns.

Fig. 13
Fig. 13

Influence of recorded mark width to the modulation amplitude. Calculation is carried out under the following conditions: The wavelength of the light is 790 nm, the numerical aperture is 0.50, and Gaussian parameter σ is 1.46.

Equations (14)

Equations on this page are rendered with MathJax. Learn more.

R ( n , k ) th R exp = 0 ,
T ( n , k ) th T exp = 0 ,
N = 1.82 i 0.09 ( unrecorded state ) , N = 1.73 i 0.28 ( recorded state ) .
R = | r | 2 ,
r = r 12 + r 23 exp ( i γ ) 1 + r 12 r 23 exp ( i γ ) ,
r 12 = N 1 N 2 N 1 + N 2 ,
r 23 = N 2 N 3 N 2 + N 3 ,
γ = 4 π d N 2 λ ,
modulation amplitude = R unrec R rec R unrec .
r = 0.74 exp ( 0.75 π i ) ( unrecorded state ) , r = 0.37 exp ( 0.69 π i ) ( recorded state ) .
τ ( x , y ) = exp [ ½ σ ( x 2 + y 2 ) ] ,
F ( ξ , η ) aperture τ ( x , y ) exp [ 2 π i ( ξ x + η y ) ] d x d y .
α ( x , y ) F ( ξ , η ) r ( ξ , η ) exp [ 2 π i ( x ξ + y η ) ] d ξ d η ,
I = aperture | α ( x , y ) | 2 d x d y .

Metrics