Abstract

A novel guided-wave optical power coupler is presented, based on two 2x2 50/50 multimode interference splitters connected with tapered waveguides that play the role of a phase shifter. By simply changing the length of this phase shifter, these double-MMI couplers can be easily designed to get any desired splitting ratio. Results of simulations are discussed and compared with the characterizations of devices fabricated on micron-scale SOI wafers, to highlight pros and cons of the proposed solution. The fabricated splitters have been found to have average losses about 0.4 ± 0.5 dB and splitting ratios ranging from 56/44 to 96/4.

© 2014 Optical Society of America

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  1. L. B. Soldano, E. C. M. Pennings, “Optical multi-mode interference devices based on self-imaging: principles and applications,” J. Lightwave Technol. 13(4), 615–627 (1995).
    [CrossRef]
  2. D. Marcuse, Theory of Dielectric Optical Waveguides (Academic Press, 1974).
  3. K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
    [CrossRef]
  4. M. Bachmann, P. A. Besse, H. Melchior, “Overlapping-image multimode interference couplers with a reduced number of self-images for uniform and nonuniform power splitting,” Appl. Opt. 34(30), 6898–6910 (1995).
    [CrossRef] [PubMed]
  5. J. Leuthold, C. W. Joyner, “Multimode interference couplers with tunable power splitting ratios,” J. Lightwave Technol. 19(5), 700–707 (2001).
    [CrossRef]
  6. Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
    [CrossRef]
  7. P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
    [CrossRef]
  8. T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
    [CrossRef]
  9. S.-Y. Tseng, C. Fuentes-Hernandez, D. Owens, B. Kippelen, “Variable splitting ratio 2 x 2 MMI couplers using multimode waveguide holograms,” Opt. Express 15(14), 9015–9021 (2007).
    [CrossRef] [PubMed]
  10. D. J. Y. Feng, T. S. Lay, “Compact multimode interference couplers with arbitrary power splitting ratio,” Opt. Express 16(10), 7175–7180 (2008).
    [CrossRef] [PubMed]
  11. M. Cherchi, “Wavelength-Flattened Directional Couplers: A Geometrical Approach,” Appl. Opt. 42(36), 7141–7148 (2003).
    [CrossRef] [PubMed]
  12. K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
    [CrossRef]
  13. F. Gao, S. Ylinen, M. Kainlauri, M. Kapulainen, “A Modified Bosch Process For Smooth Sidewall Etching,” in Proceedings of the 22nd Micromechanics and Microsystems Technology Europe Workshop (2011), pp. 69–72.
  14. M. Cherchi, “Design scheme for Mach-Zehnder interferometric coarse wavelength division multiplexing splitters and combiners,” J. Opt. Soc. Am. B 23(9), 1752 (2006).
    [CrossRef]

2008

2007

2006

M. Cherchi, “Design scheme for Mach-Zehnder interferometric coarse wavelength division multiplexing splitters and combiners,” J. Opt. Soc. Am. B 23(9), 1752 (2006).
[CrossRef]

K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
[CrossRef]

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

2003

2001

1999

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

1996

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
[CrossRef]

1995

L. B. Soldano, E. C. M. Pennings, “Optical multi-mode interference devices based on self-imaging: principles and applications,” J. Lightwave Technol. 13(4), 615–627 (1995).
[CrossRef]

M. Bachmann, P. A. Besse, H. Melchior, “Overlapping-image multimode interference couplers with a reduced number of self-images for uniform and nonuniform power splitting,” Appl. Opt. 34(30), 6898–6910 (1995).
[CrossRef] [PubMed]

Aalto, T.

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
[CrossRef]

Bachmann, M.

P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
[CrossRef]

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

M. Bachmann, P. A. Besse, H. Melchior, “Overlapping-image multimode interference couplers with a reduced number of self-images for uniform and nonuniform power splitting,” Appl. Opt. 34(30), 6898–6910 (1995).
[CrossRef] [PubMed]

Besse, P. A.

P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
[CrossRef]

M. Bachmann, P. A. Besse, H. Melchior, “Overlapping-image multimode interference couplers with a reduced number of self-images for uniform and nonuniform power splitting,” Appl. Opt. 34(30), 6898–6910 (1995).
[CrossRef] [PubMed]

Besse, P.-A.

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

Cherchi, M.

Dekker, J.

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

Feng, D. J. Y.

Fuentes-Hernandez, C.

Gao, F.

F. Gao, S. Ylinen, M. Kainlauri, M. Kapulainen, “A Modified Bosch Process For Smooth Sidewall Etching,” in Proceedings of the 22nd Micromechanics and Microsystems Technology Europe Workshop (2011), pp. 69–72.

Gini, E.

P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
[CrossRef]

Harjanne, M.

K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
[CrossRef]

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

Heimala, P.

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

Himeno, A.

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

Hunziker, W.

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

Joyner, C. W.

Kainlauri, M.

F. Gao, S. Ylinen, M. Kainlauri, M. Kapulainen, “A Modified Bosch Process For Smooth Sidewall Etching,” in Proceedings of the 22nd Micromechanics and Microsystems Technology Europe Workshop (2011), pp. 69–72.

Kapulainen, M.

K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
[CrossRef]

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

F. Gao, S. Ylinen, M. Kainlauri, M. Kapulainen, “A Modified Bosch Process For Smooth Sidewall Etching,” in Proceedings of the 22nd Micromechanics and Microsystems Technology Europe Workshop (2011), pp. 69–72.

Kippelen, B.

Lai, Q.

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

Lay, T. S.

Leuthold, J.

Melchior, H.

P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
[CrossRef]

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

M. Bachmann, P. A. Besse, H. Melchior, “Overlapping-image multimode interference couplers with a reduced number of self-images for uniform and nonuniform power splitting,” Appl. Opt. 34(30), 6898–6910 (1995).
[CrossRef] [PubMed]

Okamoto, K.

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

Okuno, M.

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

Owens, D.

Pennings, E. C. M.

L. B. Soldano, E. C. M. Pennings, “Optical multi-mode interference devices based on self-imaging: principles and applications,” J. Lightwave Technol. 13(4), 615–627 (1995).
[CrossRef]

Saida, T.

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

Soldano, L. B.

L. B. Soldano, E. C. M. Pennings, “Optical multi-mode interference devices based on self-imaging: principles and applications,” J. Lightwave Technol. 13(4), 615–627 (1995).
[CrossRef]

Solehmainen, K.

K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
[CrossRef]

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

Sugita, A.

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

Tseng, S.-Y.

Ylinen, S.

F. Gao, S. Ylinen, M. Kainlauri, M. Kapulainen, “A Modified Bosch Process For Smooth Sidewall Etching,” in Proceedings of the 22nd Micromechanics and Microsystems Technology Europe Workshop (2011), pp. 69–72.

Appl. Opt.

Electron. Lett.

T. Saida, A. Himeno, M. Okuno, A. Sugita, K. Okamoto, “Silica-based 2 × 2 multimode interference coupler with arbitrary power splitting ratio,” Electron. Lett. 35(23), 2031 (1999).
[CrossRef]

Q. Lai, M. Bachmann, W. Hunziker, P.-A. Besse, H. Melchior, “Arbitrary ratio power splitters using angled silica on silicon multimode interference couplers,” Electron. Lett. 32(17), 1576–1577 (1996).
[CrossRef]

IEEE Photon. Technol. Lett.

K. Solehmainen, M. Kapulainen, M. Harjanne, T. Aalto, “Adiabatic and Multimode Interference Couplers on Silicon-on-Insulator,” IEEE Photon. Technol. Lett. 18(21), 2287–2289 (2006).
[CrossRef]

J. Lightwave Technol.

P. A. Besse, E. Gini, M. Bachmann, H. Melchior, “New 2×2 and 1×3 multimode interference couplers with free selection of power splitting ratios,” J. Lightwave Technol. 14(10), 2286–2293 (1996).
[CrossRef]

L. B. Soldano, E. C. M. Pennings, “Optical multi-mode interference devices based on self-imaging: principles and applications,” J. Lightwave Technol. 13(4), 615–627 (1995).
[CrossRef]

J. Leuthold, C. W. Joyner, “Multimode interference couplers with tunable power splitting ratios,” J. Lightwave Technol. 19(5), 700–707 (2001).
[CrossRef]

J. Opt. A: Pure Appl. Opt.

K. Solehmainen, T. Aalto, J. Dekker, M. Kapulainen, M. Harjanne, P. Heimala, “Development of multi-step processing in silicon-on-insulator for optical waveguide applications,” J. Opt. A: Pure Appl. Opt. 8(7), S455–S460 (2006).
[CrossRef]

J. Opt. Soc. Am. B

Opt. Express

Other

F. Gao, S. Ylinen, M. Kainlauri, M. Kapulainen, “A Modified Bosch Process For Smooth Sidewall Etching,” in Proceedings of the 22nd Micromechanics and Microsystems Technology Europe Workshop (2011), pp. 69–72.

D. Marcuse, Theory of Dielectric Optical Waveguides (Academic Press, 1974).

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Figures (8)

Fig. 1
Fig. 1

(a) Top view of the proposed MZI configuration to get any wanted splitting ratios. The two connecting waveguides are tapered by the same amount but with opposite sign. (b) Cross section of a micron-scale SOI strip waveguide. (c) Simulated intensity pattern of a 70/30 splitter based on a 35.5 µm long sinusoidal taper. The width change is 500 nm. Light is launched in port 1. (d) Same as previous, when light is launched in port 2. Percentages indicate the relative output powers coupled to the fundamental modes of the output waveguides.

Fig. 2
Fig. 2

(a) Simulated power splitting in the output fundamental modes vs phase shifter length L. Cross response T12 and T21 coincide perfectly, whereas the two bar responses T11 and T22 are slightly shifted. This is better seen in (b), showing the simulated total power in the fundamental modes of the output waveguides.

Fig. 3
Fig. 3

Simulated phase difference between port 2 and port 1 vs. phase shifter length, (a) in the phase shifter alone and (b) when the light is coupled in input port 1of the whole double-MMI splitter. The splitter is the same as in Fig. 2.

Fig. 4
Fig. 4

(a) Transmitted power from input port 1 to output ports 1 and 2. The solid lines are the simulated fit corresponding to 40 nm narrower waveguides, and the experimental data are shown with ± 0.5 dB error bars. (b) Same as (a) when light is launched in port 2. (c) Optical microscope image of a fabricated double-MMI splitter.

Fig. 5
Fig. 5

(a) Comparison of simulated and experimental power imbalances. The red solid line and the black dashed line are the simulations when the input is port 1 and port 2 respectively. The experimental data are shown with ± 1 dB error bars. (b) Simulated (solid lines) and experimental (crosses and circles) normalized power percentage in the two outputs of the splitters. (c) and (d) Measured total loss with ± 0.5 dB error bars.

Fig. 6
Fig. 6

(a) Simulated impact of systematic uniform waveguide narrowing on the length of the phase shifter corresponding to π phase shift. (b) Simulated impact of 40 nm waveguide width change on the transmission in the bar port. Highlighted is the impact on the splitter of Fig. 1(d).

Fig. 7
Fig. 7

Simulated wavelength response (top row) of a splitter with 32 µm long phase shifter and corresponding experimental results (bottom row). (a) and (d) are the spectral response of all ports, (b) and (e) the power imbalance vs. wavelength, and (c) and (f) the overall losses in the fundamental mode over the considered spectral range.

Fig. 8
Fig. 8

Simulated wavelength response (top row) of a splitter with 46 µm long phase shifter and corresponding experimental results (bottom row). (a) and (d) are the spectral response of all ports, (b) and (e) the power imbalance vs. wavelength, and (c) and (f) the overall losses in the fundamental mode over the considered spectral range.

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