Abstract

We propose and demonstrate an efficient method combining proton exchange with dry etching for the fabrication of low-loss bend channel waveguides in lithium niobate (LN) thin film. Our proposed method introduces the chemical etching caused by F+ ion to increase the etching rate. Our fabricated straight and bent channel waveguides have a trapezoid cross section with a top width of ~1.0 µm, a height of ~900 nm, and a slope of ~20° with respect to the vertical direction. To the best of our knowledge, this is the largest etching depth but with a small slope reported up to now. Mode intensity distributions and insertion losses were measured at 1.55 µm wavelength and bending losses were deduced. The results show that our fabricated bent channel waveguide with a radius of 20 μm can achieve low bending losses of 0.455 dB/90° and 0.488 dB/90° for the fundamental quasi-TE (qTE) and quasi-TM (qTM) modes, respectively. Compared with the fabrication methods reported so far, our method can realize a faster etching rate and a larger etching depth while maintaining a high etching quality.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

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References

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  1. G. Poberaj, H. Hu, W. Sohler, and P. Günter, “Lithium niobate on insulator (LNOI) for micro-photonic devices,” Laser Photonics Rev. 6(4), 488–503 (2012).
    [Crossref]
  2. G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
    [Crossref]
  3. R. Geiss, S. Saravi, A. Sergeyev, S. Diziain, F. Setzpfandt, F. Schrempel, R. Grange, E. B. Kley, A. Tünnermann, and T. Pertsch, “Fabrication of nanoscale lithium niobate waveguides for second-harmonic generation,” Opt. Lett. 40(12), 2715–2718 (2015).
    [Crossref] [PubMed]
  4. P. Rabiei, J. Ma, S. Khan, J. Chiles, and S. Fathpour, “Heterogeneous lithium niobate photonics on silicon substrates,” Opt. Express 21(21), 25573–25581 (2013).
    [Crossref] [PubMed]
  5. C. Wang, M. J. Burek, Z. Lin, H. A. Atikian, V. Venkataraman, I.-C. Huang, P. Stark, and M. Lončar, “Integrated high quality factor lithium niobate microdisk resonators,” Opt. Express 22(25), 30924–30933 (2014).
    [Crossref] [PubMed]
  6. M. Bazzan and C. Sada, “Optical waveguides in lithium niobate: recent developments and applications,” Appl. Phys. Rev.  2, 040603 (2015).
  7. L. Cai, Y. Wang, and H. Hu, “Low-loss waveguides in a single-crystal lithium niobate thin film,” Opt. Lett. 40(13), 3013–3016 (2015).
    [Crossref] [PubMed]
  8. A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
    [Crossref]
  9. H. Hu, R. Ricken, and W. Sohler, “Lithium niobate photonic wires,” Opt. Express 17(26), 24261–24268 (2009).
    [Crossref] [PubMed]
  10. M. Zhang, C. Wang, R. Cheng, A. Shams-Ansari, and M. Lončar, “Monolithic ultra-high-Q lithium niobate microring resonator,” Optica 4(12), 1536–1537 (2017).
    [Crossref]
  11. L. Chen, M. G. Wood, and R. M. Reano, “12.5 pm/V hybrid silicon and lithium niobate optical microring resonator with integrated electrodes,” Opt. Express 21(22), 27003–27010 (2013).
    [Crossref] [PubMed]
  12. Y. W. Wang, Z. H. Chen, L. T. Cai, Y. P. Jiang, H. B. Zhu, and H. Hu, “Amorphous silicon-lithium niobate thin film strip-loaded waveguides,” Opt. Mater. Express 7(11), 4018–4028 (2017).
    [Crossref]
  13. A. Rao, A. Patil, P. Rabiei, A. Honardoost, R. DeSalvo, A. Paolella, and S. Fathpour, “High-performance and linear thin-film lithium niobate Mach-Zehnder modulators on silicon up to 50 GHz,” Opt. Lett. 41(24), 5700–5703 (2016).
    [Crossref] [PubMed]
  14. I. Krasnokutska, J. J. Tambasco, X. Li, and A. Peruzzo, “Ultra-low loss photonic circuits in lithium niobate on insulator,” Opt. Express 26(2), 897–904 (2018).
    [Crossref] [PubMed]
  15. H. Hu, R. Ricken, W. Sohler, and R. B. Wehrspohn, “Lithium Niobate Ridge Waveguides Fabricated by Wet Etching,” IEEE Photonics Technol. Lett. 19(6), 417–419 (2007).
    [Crossref]
  16. G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
    [Crossref]
  17. J. Godet and A. Pasquarello, “Proton diffusion mechanism in amorphous SiO2.,” Phys. Rev. Lett. 97(15), 155901 (2006).
    [Crossref] [PubMed]

2018 (1)

2017 (2)

2016 (1)

2015 (3)

2014 (1)

2013 (2)

2012 (1)

G. Poberaj, H. Hu, W. Sohler, and P. Günter, “Lithium niobate on insulator (LNOI) for micro-photonic devices,” Laser Photonics Rev. 6(4), 488–503 (2012).
[Crossref]

2009 (2)

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

H. Hu, R. Ricken, and W. Sohler, “Lithium niobate photonic wires,” Opt. Express 17(26), 24261–24268 (2009).
[Crossref] [PubMed]

2008 (1)

G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
[Crossref]

2007 (2)

H. Hu, R. Ricken, W. Sohler, and R. B. Wehrspohn, “Lithium Niobate Ridge Waveguides Fabricated by Wet Etching,” IEEE Photonics Technol. Lett. 19(6), 417–419 (2007).
[Crossref]

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

2006 (1)

J. Godet and A. Pasquarello, “Proton diffusion mechanism in amorphous SiO2.,” Phys. Rev. Lett. 97(15), 155901 (2006).
[Crossref] [PubMed]

Atikian, H. A.

Bazzan, M.

M. Bazzan and C. Sada, “Optical waveguides in lithium niobate: recent developments and applications,” Appl. Phys. Rev.  2, 040603 (2015).

Burek, M. J.

Cai, L.

Cai, L. T.

Chen, L.

Chen, Z. H.

Cheng, R.

Chiles, J.

Chong, H. M. H.

G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
[Crossref]

Courjal, N.

G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
[Crossref]

De La Rue, R. M.

G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
[Crossref]

Degl’innocenti, R.

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

DeSalvo, R.

Diziain, S.

Fathpour, S.

Geiss, R.

Godet, J.

J. Godet and A. Pasquarello, “Proton diffusion mechanism in amorphous SiO2.,” Phys. Rev. Lett. 97(15), 155901 (2006).
[Crossref] [PubMed]

Grange, R.

Guarino, A.

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

Günter, P.

G. Poberaj, H. Hu, W. Sohler, and P. Günter, “Lithium niobate on insulator (LNOI) for micro-photonic devices,” Laser Photonics Rev. 6(4), 488–503 (2012).
[Crossref]

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

Hajfler, J.

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

Honardoost, A.

Hu, H.

Huang, I.-C.

Jiang, Y. P.

Khan, S.

Kley, E. B.

Koechlin, M.

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

Krasnokutska, I.

Li, X.

Lin, Z.

Loncar, M.

Ma, J.

Paolella, A.

Pasquarello, A.

J. Godet and A. Pasquarello, “Proton diffusion mechanism in amorphous SiO2.,” Phys. Rev. Lett. 97(15), 155901 (2006).
[Crossref] [PubMed]

Patil, A.

Pertsch, T.

Peruzzo, A.

Poberaj, G.

G. Poberaj, H. Hu, W. Sohler, and P. Günter, “Lithium niobate on insulator (LNOI) for micro-photonic devices,” Laser Photonics Rev. 6(4), 488–503 (2012).
[Crossref]

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

Rabiei, P.

Rao, A.

Reano, R. M.

Rezzonico, D.

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

Ricken, R.

H. Hu, R. Ricken, and W. Sohler, “Lithium niobate photonic wires,” Opt. Express 17(26), 24261–24268 (2009).
[Crossref] [PubMed]

H. Hu, R. Ricken, W. Sohler, and R. B. Wehrspohn, “Lithium Niobate Ridge Waveguides Fabricated by Wet Etching,” IEEE Photonics Technol. Lett. 19(6), 417–419 (2007).
[Crossref]

Sada, C.

M. Bazzan and C. Sada, “Optical waveguides in lithium niobate: recent developments and applications,” Appl. Phys. Rev.  2, 040603 (2015).

Saravi, S.

Schrempel, F.

Sergeyev, A.

Setzpfandt, F.

Shams-Ansari, A.

Sohler, W.

G. Poberaj, H. Hu, W. Sohler, and P. Günter, “Lithium niobate on insulator (LNOI) for micro-photonic devices,” Laser Photonics Rev. 6(4), 488–503 (2012).
[Crossref]

H. Hu, R. Ricken, and W. Sohler, “Lithium niobate photonic wires,” Opt. Express 17(26), 24261–24268 (2009).
[Crossref] [PubMed]

H. Hu, R. Ricken, W. Sohler, and R. B. Wehrspohn, “Lithium Niobate Ridge Waveguides Fabricated by Wet Etching,” IEEE Photonics Technol. Lett. 19(6), 417–419 (2007).
[Crossref]

Stark, P.

Sulser, F.

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

Tambasco, J. J.

Tünnermann, A.

Ulliac, G.

G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
[Crossref]

Venkataraman, V.

Wang, C.

Wang, Y.

Wang, Y. W.

Wehrspohn, R. B.

H. Hu, R. Ricken, W. Sohler, and R. B. Wehrspohn, “Lithium Niobate Ridge Waveguides Fabricated by Wet Etching,” IEEE Photonics Technol. Lett. 19(6), 417–419 (2007).
[Crossref]

Wood, M. G.

Zhang, M.

Zhu, H. B.

Appl. Phys. Rev (1)

M. Bazzan and C. Sada, “Optical waveguides in lithium niobate: recent developments and applications,” Appl. Phys. Rev.  2, 040603 (2015).

IEEE Photonics Technol. Lett. (1)

H. Hu, R. Ricken, W. Sohler, and R. B. Wehrspohn, “Lithium Niobate Ridge Waveguides Fabricated by Wet Etching,” IEEE Photonics Technol. Lett. 19(6), 417–419 (2007).
[Crossref]

Laser Photonics Rev. (1)

G. Poberaj, H. Hu, W. Sohler, and P. Günter, “Lithium niobate on insulator (LNOI) for micro-photonic devices,” Laser Photonics Rev. 6(4), 488–503 (2012).
[Crossref]

Nat. Photonics (1)

A. Guarino, G. Poberaj, D. Rezzonico, R. Degl’innocenti, and P. Günter, “Electro–optically tunable microring resonators in lithium niobate,” Nat. Photonics 1(7), 407–410 (2007).
[Crossref]

Opt. Express (5)

Opt. Lett. (3)

Opt. Mater. (2)

G. Poberaj, M. Koechlin, F. Sulser, A. Guarino, J. Hajfler, and P. Günter, “Ion-sliced lithium niobate thin films for active photonic devices,” Opt. Mater. 31(7), 1054–1058 (2009).
[Crossref]

G. Ulliac, N. Courjal, H. M. H. Chong, and R. M. De La Rue, “Batch process for the fabrication of LiNbO3 photonic crystals using proton exchange followed by CHF3 reactive ion etching,” Opt. Mater. 31(2), 196–200 (2008).
[Crossref]

Opt. Mater. Express (1)

Optica (1)

Phys. Rev. Lett. (1)

J. Godet and A. Pasquarello, “Proton diffusion mechanism in amorphous SiO2.,” Phys. Rev. Lett. 97(15), 155901 (2006).
[Crossref] [PubMed]

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Figures (6)

Fig. 1
Fig. 1 Configuration of the straight tand the 4 × 90° bent channel waveguides.
Fig. 2
Fig. 2 Fabrication process fora channel waveguide in the X-cut LN thin film: (a) Cr deposition;(b) photoresist spin-coating; (c) photolithography; (d) Cr corrosion; (e) photoresist removal;(f) proton exchange,(g) ICP etching; (h) Cr removal.
Fig. 3
Fig. 3 Scanning electron microscope pictures of the fabricated4 × 90° bent channel waveguide with a radius of 5 μm (a) and corresponding input (output) waveguide (b), as well as the straight reference waveguide (c) and corresponding input (output) waveguide (d)
Fig. 4
Fig. 4 Measured intensity distributions of the fundamental mode at 1.55μm wavelength in the fabricated LN straight waveguide,(a) qTE mode, (b) qTM mode, and in the fabricated4 × 90° bent channel waveguide with 5 μm radius, (c) qTE mode, (d) qTM mode, with a pair of tapered waveguides as the input and output waveguides.
Fig. 5
Fig. 5 Simulated electric field intensity distributions of the modes using the parameters of the fabricated ~1.0-μm width channel waveguide at 1.55μm wavelength for the qTE polarization: (a) the fundamental mode, (b) the second order mode, and for the qTM polarization:(c) the fundamental mode, (d) the second order mode.
Fig. 6
Fig. 6 Bend losses of the fabricated 90° bent LN channel waveguides with different radii for the fundamental qTE and qTM modes at 1550 nm wavelength.

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