Abstract

We report an investigation on angle-cut beta barium borate (BBO) whispering gallery mode (WGM) resonators operating in the ultra violet (UV) wavelength range. A quality (Q) factor of 1.5 × 108 has been demonstrated at 370 nm. New upper bounds for the absorption coefficients of BBO are obtained from the Q factor measurements. Moreover, polarization rotations of WGMs in the angle-cut birefringent resonators are observed and investigated. To the best of our knowledge, this is not only the first reported demonstration of an angle-cut WGM resonator but also the first reported high Q WGM resonator in the UV region.

© 2012 OSA

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  1. L. V. B. Braginsky, M. L. Gorodetsky, and V. S. Ilchenko, “Quality-factor and nonlinear properties of optical whispering-gallery modes,” Phys. Lett. A137(7-8), 393–397 (1989).
    [CrossRef]
  2. D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
    [CrossRef] [PubMed]
  3. A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
    [CrossRef]
  4. C. G. B. Garrett, W. Kaiser, and W. L. Bond, “Stimulated emission into optical whispering modes of spheres,” Phys. Rev.124(6), 1807–1809 (1961).
    [CrossRef]
  5. V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
    [CrossRef] [PubMed]
  6. J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
    [CrossRef] [PubMed]
  7. J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
    [CrossRef] [PubMed]
  8. K. Sasagawa and M. Tsuchiya, “Highly efficient third harmonic generation in a periodically poled MgO:LiNbO3 disk resonator,” Appl. Phys. Express2(12), 122401 (2009).
    [CrossRef]
  9. T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
    [CrossRef] [PubMed]
  10. J. Moore, M. Tomes, T. Carmon, and M. Jarrahi, “Continuous-wave ultraviolet emission through fourth-harmonic generation in a whispering-gallery resonator,” Opt. Express19(24), 24139–24146 (2011).
    [CrossRef] [PubMed]
  11. A. A. Savchenkov, W. Liang, A. B. Matsko, V. S. Ilchenko, D. Seidel, and L. Maleki, “Tunable optical single-sideband modulator with complete sideband suppression,” Opt. Lett.34(9), 1300–1302 (2009).
    [CrossRef] [PubMed]
  12. D. N. Nikogosyan, “Beta barium borate (BBO),” Appl. Phys., A Mater. Sci. Process.52(6), 359–368 (1991).
    [CrossRef]
  13. We are aware of the work on WGM resonators made of angle cut MgF2 by the group of Harald Schwefel at the MPL Erlangen. (private communications).
  14. K. Kato, “Second-harmonic generation to 2048 Å in β-BaB2O4,” IEEE J. Quantum Electron.22(7), 1013–1014 (1986).
    [CrossRef]
  15. M. C. Simon and R. M. Echarri, “Inhibited reflection in uniaxial crystals,” Opt. Lett.14(5), 257–259 (1989).
    [CrossRef] [PubMed]

2011

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

J. Moore, M. Tomes, T. Carmon, and M. Jarrahi, “Continuous-wave ultraviolet emission through fourth-harmonic generation in a whispering-gallery resonator,” Opt. Express19(24), 24139–24146 (2011).
[CrossRef] [PubMed]

2010

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

2009

K. Sasagawa and M. Tsuchiya, “Highly efficient third harmonic generation in a periodically poled MgO:LiNbO3 disk resonator,” Appl. Phys. Express2(12), 122401 (2009).
[CrossRef]

A. A. Savchenkov, W. Liang, A. B. Matsko, V. S. Ilchenko, D. Seidel, and L. Maleki, “Tunable optical single-sideband modulator with complete sideband suppression,” Opt. Lett.34(9), 1300–1302 (2009).
[CrossRef] [PubMed]

2004

A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
[CrossRef]

V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
[CrossRef] [PubMed]

2003

D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
[CrossRef] [PubMed]

1991

D. N. Nikogosyan, “Beta barium borate (BBO),” Appl. Phys., A Mater. Sci. Process.52(6), 359–368 (1991).
[CrossRef]

1989

L. V. B. Braginsky, M. L. Gorodetsky, and V. S. Ilchenko, “Quality-factor and nonlinear properties of optical whispering-gallery modes,” Phys. Lett. A137(7-8), 393–397 (1989).
[CrossRef]

M. C. Simon and R. M. Echarri, “Inhibited reflection in uniaxial crystals,” Opt. Lett.14(5), 257–259 (1989).
[CrossRef] [PubMed]

1986

K. Kato, “Second-harmonic generation to 2048 Å in β-BaB2O4,” IEEE J. Quantum Electron.22(7), 1013–1014 (1986).
[CrossRef]

1961

C. G. B. Garrett, W. Kaiser, and W. L. Bond, “Stimulated emission into optical whispering modes of spheres,” Phys. Rev.124(6), 1807–1809 (1961).
[CrossRef]

Aiello, A.

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

Andersen, U. L.

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

Armani, D. K.

D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
[CrossRef] [PubMed]

Beckmann, T.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Bond, W. L.

C. G. B. Garrett, W. Kaiser, and W. L. Bond, “Stimulated emission into optical whispering modes of spheres,” Phys. Rev.124(6), 1807–1809 (1961).
[CrossRef]

Braginsky, L. V. B.

L. V. B. Braginsky, M. L. Gorodetsky, and V. S. Ilchenko, “Quality-factor and nonlinear properties of optical whispering-gallery modes,” Phys. Lett. A137(7-8), 393–397 (1989).
[CrossRef]

Breunig, I.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Buse, K.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Carmon, T.

Echarri, R. M.

Elser, D.

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

Fürst, J. U.

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

Garrett, C. G. B.

C. G. B. Garrett, W. Kaiser, and W. L. Bond, “Stimulated emission into optical whispering modes of spheres,” Phys. Rev.124(6), 1807–1809 (1961).
[CrossRef]

Gorodetsky, M. L.

L. V. B. Braginsky, M. L. Gorodetsky, and V. S. Ilchenko, “Quality-factor and nonlinear properties of optical whispering-gallery modes,” Phys. Lett. A137(7-8), 393–397 (1989).
[CrossRef]

Haertle, D.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Ilchenko, V. S.

A. A. Savchenkov, W. Liang, A. B. Matsko, V. S. Ilchenko, D. Seidel, and L. Maleki, “Tunable optical single-sideband modulator with complete sideband suppression,” Opt. Lett.34(9), 1300–1302 (2009).
[CrossRef] [PubMed]

A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
[CrossRef]

V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
[CrossRef] [PubMed]

L. V. B. Braginsky, M. L. Gorodetsky, and V. S. Ilchenko, “Quality-factor and nonlinear properties of optical whispering-gallery modes,” Phys. Lett. A137(7-8), 393–397 (1989).
[CrossRef]

Jarrahi, M.

Kaiser, W.

C. G. B. Garrett, W. Kaiser, and W. L. Bond, “Stimulated emission into optical whispering modes of spheres,” Phys. Rev.124(6), 1807–1809 (1961).
[CrossRef]

Kato, K.

K. Kato, “Second-harmonic generation to 2048 Å in β-BaB2O4,” IEEE J. Quantum Electron.22(7), 1013–1014 (1986).
[CrossRef]

Kippenberg, T. J.

D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
[CrossRef] [PubMed]

Lassen, M.

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

Leuchs, G.

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

Liang, W.

Linnenbank, H.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Maleki, L.

A. A. Savchenkov, W. Liang, A. B. Matsko, V. S. Ilchenko, D. Seidel, and L. Maleki, “Tunable optical single-sideband modulator with complete sideband suppression,” Opt. Lett.34(9), 1300–1302 (2009).
[CrossRef] [PubMed]

A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
[CrossRef]

V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
[CrossRef] [PubMed]

Marquardt, C.

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

Marquardt, Ch.

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

Matsko, A. B.

A. A. Savchenkov, W. Liang, A. B. Matsko, V. S. Ilchenko, D. Seidel, and L. Maleki, “Tunable optical single-sideband modulator with complete sideband suppression,” Opt. Lett.34(9), 1300–1302 (2009).
[CrossRef] [PubMed]

V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
[CrossRef] [PubMed]

A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
[CrossRef]

Moore, J.

Nikogosyan, D. N.

D. N. Nikogosyan, “Beta barium borate (BBO),” Appl. Phys., A Mater. Sci. Process.52(6), 359–368 (1991).
[CrossRef]

Sasagawa, K.

K. Sasagawa and M. Tsuchiya, “Highly efficient third harmonic generation in a periodically poled MgO:LiNbO3 disk resonator,” Appl. Phys. Express2(12), 122401 (2009).
[CrossRef]

Savchenkov, A. A.

A. A. Savchenkov, W. Liang, A. B. Matsko, V. S. Ilchenko, D. Seidel, and L. Maleki, “Tunable optical single-sideband modulator with complete sideband suppression,” Opt. Lett.34(9), 1300–1302 (2009).
[CrossRef] [PubMed]

V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
[CrossRef] [PubMed]

A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
[CrossRef]

Seidel, D.

Simon, M. C.

Spillane, S. M.

D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
[CrossRef] [PubMed]

Steigerwald, H.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Strekalov, D. V.

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

Sturman, B.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

Tomes, M.

Tsuchiya, M.

K. Sasagawa and M. Tsuchiya, “Highly efficient third harmonic generation in a periodically poled MgO:LiNbO3 disk resonator,” Appl. Phys. Express2(12), 122401 (2009).
[CrossRef]

Vahala, K. J.

D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
[CrossRef] [PubMed]

Appl. Phys. Express

K. Sasagawa and M. Tsuchiya, “Highly efficient third harmonic generation in a periodically poled MgO:LiNbO3 disk resonator,” Appl. Phys. Express2(12), 122401 (2009).
[CrossRef]

Appl. Phys., A Mater. Sci. Process.

D. N. Nikogosyan, “Beta barium borate (BBO),” Appl. Phys., A Mater. Sci. Process.52(6), 359–368 (1991).
[CrossRef]

IEEE J. Quantum Electron.

K. Kato, “Second-harmonic generation to 2048 Å in β-BaB2O4,” IEEE J. Quantum Electron.22(7), 1013–1014 (1986).
[CrossRef]

Nature

D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(6926), 925–928 (2003).
[CrossRef] [PubMed]

Opt. Express

Opt. Lett.

Phys. Lett. A

L. V. B. Braginsky, M. L. Gorodetsky, and V. S. Ilchenko, “Quality-factor and nonlinear properties of optical whispering-gallery modes,” Phys. Lett. A137(7-8), 393–397 (1989).
[CrossRef]

Phys. Rev.

C. G. B. Garrett, W. Kaiser, and W. L. Bond, “Stimulated emission into optical whispering modes of spheres,” Phys. Rev.124(6), 1807–1809 (1961).
[CrossRef]

Phys. Rev. A

A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, “Kilohertz optical resonances in dielectric crystal cavities,” Phys. Rev. A70(5), 051804 (2004).
[CrossRef]

Phys. Rev. Lett.

T. Beckmann, H. Linnenbank, H. Steigerwald, B. Sturman, D. Haertle, K. Buse, and I. Breunig, “Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators,” Phys. Rev. Lett.106(14), 143903 (2011).
[CrossRef] [PubMed]

V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, and L. Maleki, “Nonlinear optics and crystalline whispering gallery mode cavities,” Phys. Rev. Lett.92(4), 043903 (2004).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, M. Lassen, U. L. Andersen, C. Marquardt, and G. Leuchs, “Naturally phase-matched second-harmonic generation in a whispering-gallery-mode resonator,” Phys. Rev. Lett.104(15), 153901 (2010).
[CrossRef] [PubMed]

J. U. Fürst, D. V. Strekalov, D. Elser, A. Aiello, U. L. Andersen, Ch. Marquardt, and G. Leuchs, “Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator,” Phys. Rev. Lett.105(26), 263904 (2010).
[CrossRef] [PubMed]

Other

We are aware of the work on WGM resonators made of angle cut MgF2 by the group of Harald Schwefel at the MPL Erlangen. (private communications).

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Figures (4)

Fig. 1
Fig. 1

Schematic of the experimental setup for Q measurements at the UV wavelength. Inset: photo of a BBO resonator with the marked optic axis.

Fig. 2
Fig. 2

One example of a reflection spectrum (upper curve) of a 33°-cut BBO crystal WGM resonator at 370 nm and the corresponding Q measurement. The lower curve is the reference Fabry-Perot cavity spectrum (FSR = 300 MHz).

Fig. 3
Fig. 3

(a): Illustration of the crystal cut angle γ, the resonator position β, the input beam polarization orientation and WGM polarization ψ. (N): optic axis. The gap between the resonator and the coupling prism is highly exaggerated for clarity. (b): A set of observed spectra of the 33° cut BBO resonator for different input polarization . (c): The measured excitation efficiency of a selected WGM as a function of the polarization orientation and the cosine square function fit. Note: 2θ0 is the optimal input polarization for maximum excitation.

Fig. 4
Fig. 4

Polarization orientation along the WGM disk circumference: measured optimal coupling angle of the incident light (data points), computed polarization orientation of the ordinary ray inside the resonator (dashed lines), and the fit of the transformed input polarization inside the resonator (solid lines).

Tables (1)

Tables Icon

Table 1 The measured WGM linewidths, Q factors and the corresponding upper bounds of absorption coefficients of BBO

Metrics