Abstract

Ghosts and flares are well-known problems that are caused by reflections from lens surfaces when we take photographs. It is more difficult to prevent such stray light in a digital camera than in a film camera because of high reflectance from the low-pass filter and diffraction from the image sensor. To prevent such stray light, we introduce an ultralow refractive index layer into the antireflective (AR) coatings. We used the solgel method to form porous fluoride layers with ultralow refractive indices, and we succeeded in developing a unique process to form AR coatings with superior performance.

© 2011 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. T. Murata, H. Ishizawa, I. Motoyama, and A. Tanaka, “Investigations of MgF2 optical thin films prepared from autoclaved sol,” J. Sol-Gel Sci. Technol. 32, 161–165 (2004).
    [CrossRef]
  2. T. Murata, H. Ishizawa, I. Motoyama, and A. Tanaka, “Preparation of high performance optical coatings with fluoride-nano-particle films made from autoclaved sols,” Appl. Opt. 45, 1465–1468 (2006).
    [CrossRef] [PubMed]
  3. T. Murata, H. Ishizawa, I. Motoyama, and A. Tanaka, “Investigation of MgF2 optical thin films with ultralow refractive indices prepared from autoclaved sol,” Appl. Opt. 47, C246–C250 (2008).
    [CrossRef] [PubMed]
  4. S. S. Kistler, “Coherent expanded aerogels and jellies,” Nature 127, 741–741 (1931).
    [CrossRef]
  5. G. A. Nicolaon and S. J. Teichner, “Préparation des aérogels de silice à partir d’orthosilicate de méthyle en milieu alcoolique et leurs propriétés,” Bull. Soc. Chem. Fr. 5, 1906–1911 (1968).
  6. B. E. Yoldas, “Investigations of porous oxides as an antireflective coating for glass surfaces,” Appl. Opt. 19, 1425–1429(1980).
    [CrossRef] [PubMed]

2008 (1)

2006 (1)

2004 (1)

T. Murata, H. Ishizawa, I. Motoyama, and A. Tanaka, “Investigations of MgF2 optical thin films prepared from autoclaved sol,” J. Sol-Gel Sci. Technol. 32, 161–165 (2004).
[CrossRef]

1980 (1)

1968 (1)

G. A. Nicolaon and S. J. Teichner, “Préparation des aérogels de silice à partir d’orthosilicate de méthyle en milieu alcoolique et leurs propriétés,” Bull. Soc. Chem. Fr. 5, 1906–1911 (1968).

1931 (1)

S. S. Kistler, “Coherent expanded aerogels and jellies,” Nature 127, 741–741 (1931).
[CrossRef]

Ishizawa, H.

Kistler, S. S.

S. S. Kistler, “Coherent expanded aerogels and jellies,” Nature 127, 741–741 (1931).
[CrossRef]

Motoyama, I.

Murata, T.

Nicolaon, G. A.

G. A. Nicolaon and S. J. Teichner, “Préparation des aérogels de silice à partir d’orthosilicate de méthyle en milieu alcoolique et leurs propriétés,” Bull. Soc. Chem. Fr. 5, 1906–1911 (1968).

Tanaka, A.

Teichner, S. J.

G. A. Nicolaon and S. J. Teichner, “Préparation des aérogels de silice à partir d’orthosilicate de méthyle en milieu alcoolique et leurs propriétés,” Bull. Soc. Chem. Fr. 5, 1906–1911 (1968).

Yoldas, B. E.

Appl. Opt. (3)

Bull. Soc. Chem. Fr. (1)

G. A. Nicolaon and S. J. Teichner, “Préparation des aérogels de silice à partir d’orthosilicate de méthyle en milieu alcoolique et leurs propriétés,” Bull. Soc. Chem. Fr. 5, 1906–1911 (1968).

J. Sol-Gel Sci. Technol. (1)

T. Murata, H. Ishizawa, I. Motoyama, and A. Tanaka, “Investigations of MgF2 optical thin films prepared from autoclaved sol,” J. Sol-Gel Sci. Technol. 32, 161–165 (2004).
[CrossRef]

Nature (1)

S. S. Kistler, “Coherent expanded aerogels and jellies,” Nature 127, 741–741 (1931).
[CrossRef]

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 (8)

Fig. 1
Fig. 1

Difference between (A) a single-lens reflex film camera and (B) a single-lens reflex digital camera.

Fig. 2
Fig. 2

SEM image of a single-layer MgF 2 coating made from autoclaved sol on glass substrate.

Fig. 3
Fig. 3

Simulated relations between the refractive indices of the top layers of AR coatings for visible light and the reflectances (substrate, BSC7; stack, seven layers; incident angles, 0, 15, 30, 45, 60 ° ). The refractive indices of the top layer were (A) 1.39 at 550 nm , (B) 1.30 at 550 nm , (C) 1.25 at 550 nm , and (D) 1.20 at 550 nm .

Fig. 4
Fig. 4

Reflectance of a wedged glass substrate with a hybrid AR coating on one side measured in the visible wavelength range [stack, nine layers (the eight layers on the substrate side were formed by magnetron sputtering); refractive index of the substrate, 1.59 at 550 nm ].

Fig. 5
Fig. 5

Reflectance of a wedged glass substrate with AR coating on one side measured in the visible wavelength range (stack, single layer; refractive index of the substrate, 1.75 at 550 nm ).

Fig. 6
Fig. 6

Image of dummy lens barrels to compare the properties of AR coatings: (A) cross-section configuration figure of a sample; (B) a photograph of the samples taken under oblique-incidence illumination: (a) without coating, (b) with conventional coating, (c) with nanoparticle coating.

Fig. 7
Fig. 7

Images taken with wide-angle zoom lenses: (a-1) nanoparticle coating lens at F11, (a-2) nanoparticle coating lens at F22, (b-1) conventional coating lens at F11, and (b-2) conventional coating lens at F22.

Fig. 8
Fig. 8

Comparison of the ghost intensity in IR images: (a-1) visible image taken with a nanoparticle coating lens, (a-2) IR image taken with a nanoparticle coating lens, (b-1) visible image taken with a conventional coating lens, (b-2) IR image taken with a conventional coating lens.

Tables (5)

Tables Icon

Table 1 Comparisons of Reflectances and Backscatterings among Film, Low-Pass Filter, and Image Sensor

Tables Icon

Table 2 Stack Configurations of Antireflection Coatings for Simulation Shown in Fig. 3

Tables Icon

Table 3 Stack Configuration of Antireflection Coating Shown in Fig. 4

Tables Icon

Table 4 Optical Constants of the Top Layer of the Antireflection Coating Shown in Fig. 4

Tables Icon

Table 5 Optical Constants of the Nanoparticle Layer of the AR Coating Shown in Fig. 5

Equations (1)

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

n 1 2 = n 0 n .

Metrics