Abstract

We propose what is, to our knowledge, a novel technique for fabricating a segmented waveguide by optical irradiation in a photorefractive LiNbO3:Fe crystal. The waveguide consists of many localized high-refractive-index regions that are fabricated by illumination of a focused laser beam. We fabricate straight, curved, and Y-branch waveguides. In the straight waveguides the transmitted power of a guided beam as a function of the period of segmentation and the dark decay time are measured. The tolerance for fabrication errors is also investigated both experimentally and numerically. The fabricated waveguide can be optically modified. We demonstrate that a curved structure can be transformed into a Y-branch structure.

[Optical Society of America ]

Full Article  |  PDF Article

References

  • View by:
  • |
  • |

  1. S. J. Frisken , Light-induced optical waveguide uptapers , Opt. Lett. OPLEDP 18 , 1035 1037 ( 1993
    [CrossRef] [PubMed]
  2. K. M. Davis , K. Miura , N. Sugimoto , and K. Hirao , Writing waveguides in glass with a femtosecond laser , Opt. Lett. OPLEDP 21 , 1729 1731 ( 1996
    [CrossRef] [PubMed]
  3. A. S. Kewitsch and A. Yariv , Self-focusing and self-trapping of optical beams upon photopolymerization , Opt. Lett. OPLEDP 21 , 24 26 ( 1996
    [CrossRef] [PubMed]
  4. K. Itoh , O. Matoba , and Y. Ichioka , Fabrication experiment of photorefractive three-dimensional waveguides in lithium niobate , Opt. Lett. OPLEDP 19 , 652 654 ( 1994
    [CrossRef] [PubMed]
  5. O. Matoba , K. Itoh , and Y. Ichioka , Array of photorefractive waveguides for massively parallel optical interconnections in lithium niobate , Opt. Lett. OPLEDP 21 , 122 124 ( 1996
    [CrossRef] [PubMed]
  6. S. Lan , M. Shih , and M. Segev , Self-trapping of one-dimensional and two-dimensional optical beams and induced waveguides in photorefractive KNbO 3 , Opt. Lett. OPLEDP 22 , 1467 1469 ( 1997
    [CrossRef]
  7. O. Matoba , K. Ikezawa , K. Itoh , and Y. Ichioka , Modification of photorefractive waveguides in lithium niobate by guided beam for optical dynamic interconnection , Opt. Rev. OPREFN 2 , 438 443 ( 1995
    [CrossRef]
  8. Z. Weissman and A. Hardy , Modes of periodically segmented waveguides , J. Lightwave Technol. JLTEDG 11 , 1831 1838 ( 1993
    [CrossRef]
  9. K. Thyagarajan , C. W. Chien , R. V. Ramaswamy , H. S. Kim , and H. C. Cheng , Proton-exchanged periodically segmented waveguides in LiNbO 3 , Opt. Lett. OPLEDP 19 , 880 882 ( 1994
    [CrossRef] [PubMed]
  10. A. M. Glass , The photorefractive effect , Opt. Eng. OPEGAR 17 , 470 479 ( 1978
    [CrossRef]
  11. F. S. Chen , Optically induced change of refractive indices in LiNbO 3 and LiTaO 3 , J. Appl. Phys. JAPIAU 40 , 3389 3396 ( 1969
    [CrossRef]
  12. See, for example , R. Scarmozzino and R. M. Osgood , Jr. , Comparison of finite-difference and Fourier-transform solutions of the parabolic wave equation with emphasis on integrated-optics applications , J. Opt. Soc. Am. A JOAOD6 8 , 724 731 ( 1991
    [CrossRef]

Other (12)

S. J. Frisken , Light-induced optical waveguide uptapers , Opt. Lett. OPLEDP 18 , 1035 1037 ( 1993
[CrossRef] [PubMed]

K. M. Davis , K. Miura , N. Sugimoto , and K. Hirao , Writing waveguides in glass with a femtosecond laser , Opt. Lett. OPLEDP 21 , 1729 1731 ( 1996
[CrossRef] [PubMed]

A. S. Kewitsch and A. Yariv , Self-focusing and self-trapping of optical beams upon photopolymerization , Opt. Lett. OPLEDP 21 , 24 26 ( 1996
[CrossRef] [PubMed]

K. Itoh , O. Matoba , and Y. Ichioka , Fabrication experiment of photorefractive three-dimensional waveguides in lithium niobate , Opt. Lett. OPLEDP 19 , 652 654 ( 1994
[CrossRef] [PubMed]

O. Matoba , K. Itoh , and Y. Ichioka , Array of photorefractive waveguides for massively parallel optical interconnections in lithium niobate , Opt. Lett. OPLEDP 21 , 122 124 ( 1996
[CrossRef] [PubMed]

S. Lan , M. Shih , and M. Segev , Self-trapping of one-dimensional and two-dimensional optical beams and induced waveguides in photorefractive KNbO 3 , Opt. Lett. OPLEDP 22 , 1467 1469 ( 1997
[CrossRef]

O. Matoba , K. Ikezawa , K. Itoh , and Y. Ichioka , Modification of photorefractive waveguides in lithium niobate by guided beam for optical dynamic interconnection , Opt. Rev. OPREFN 2 , 438 443 ( 1995
[CrossRef]

Z. Weissman and A. Hardy , Modes of periodically segmented waveguides , J. Lightwave Technol. JLTEDG 11 , 1831 1838 ( 1993
[CrossRef]

K. Thyagarajan , C. W. Chien , R. V. Ramaswamy , H. S. Kim , and H. C. Cheng , Proton-exchanged periodically segmented waveguides in LiNbO 3 , Opt. Lett. OPLEDP 19 , 880 882 ( 1994
[CrossRef] [PubMed]

A. M. Glass , The photorefractive effect , Opt. Eng. OPEGAR 17 , 470 479 ( 1978
[CrossRef]

F. S. Chen , Optically induced change of refractive indices in LiNbO 3 and LiTaO 3 , J. Appl. Phys. JAPIAU 40 , 3389 3396 ( 1969
[CrossRef]

See, for example , R. Scarmozzino and R. M. Osgood , Jr. , Comparison of finite-difference and Fourier-transform solutions of the parabolic wave equation with emphasis on integrated-optics applications , J. Opt. Soc. Am. A JOAOD6 8 , 724 731 ( 1991
[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 (13)

Fig. 1
Fig. 1

Schematic of segmented photorefractive waveguides with various structures.

Fig. 2
Fig. 2

Illustrations of optical interconnections by use of SPW’s. (a) One can select various interconnection paths by shifting an input position or tilting an incidence angle. (b) Description of the modification of waveguide functions. If a new high-index region represented by a filled circle is created by optical illumination, a new interconnection path can be created. When the high-index region is erased, the path can be erased.

Fig. 3
Fig. 3

Illustrations of the profile of refractive-index change caused by a focused beam in LiNbO3 crystal. (a) Intensity distribution, I; (b) space-charge density, ρ; (c) refractive-index change, Δn; and (d) refractive-index change, Δn, induced by sandwich illumination.

Fig. 4
Fig. 4

Experimental setup. OL’s, microscope objective lenses; NDF, neutral-density filter; TR, translator; P, polarizer; PC, personal computer.

Fig. 5
Fig. 5

Experimental results in the straight SPW. (a) Near-field patterns after the fabrication; (b), (c) their cross-sectional profiles of intensity distributions along the vertical and horizontal axes, respectively.

Fig. 6
Fig. 6

Output power as a function of period in straight SPW’s.

Fig. 7
Fig. 7

Output power density from the straight SPW as a function of time t at room temperature in the dark.    

Fig. 8
Fig. 8

Output power of the guided beam as a function of σ in waveguides that have position errors along the z axis.

Fig. 9
Fig. 9

Output power of the guided beam as a function of σ in waveguides that have position errors along the x axis.

Fig. 10
Fig. 10

Error in SPW’s that have position errors along the z axis as a function of σ for various duty cycles.  

Fig. 11
Fig. 11

Error in SPW’s that have position errors along the y axis as a function of σ for various duty cycles.  

Fig. 12
Fig. 12

Illustrations of (a) a curved and (b) a Y-branch structure. The hatched, filled, and open squares denote illuminated positions, used cells, and unused cells, respectively.

Fig. 13
Fig. 13

Near-field patterns of (a) a curved and (b) a Y-branch structure. (c) Their cross sections along the vertical axis.  

Equations (1)

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

E=xy[In(x, y)-Iw(x, y)]2xy[In(x, y)+Iw(x, y)]2,

Metrics