Abstract

The authors describe a general method to extract the frequency chirping of Mach-Zehnder modulators based on direct measurements of the output spectrum. This method is independent of the modulator extinction ratio and allows measurement of the intrinsic chirp parameter to an accuracy of 5%.

© 2004 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |

  1. S.K Kim, O. Mizuhara, Y.K. Park, L.D. Tzeng, Y.S. Kim, and J. Jeong, " Theoritical and experimental study of 10 Gb/s transmission performance using 1.55 m LiNbO3-Based transmitters with adjustable extinction ration and chirp," J. Lightwave Technol. 7, 1320-1325 (1999).
  2. L.S. Yan, Q. Yu, A.E. Willner, and Y. Shi, �?? Measurement of the chirp parameter of electro-optic modulators by comparison of the phase between the two sidebands,�?? Opt. Lett. 28, 1114-1116 (2003).
    [CrossRef] [PubMed]
  3. S. Oikawa, T. Kawanishi, and M. Izutsu, �??Measurement of chirp parameters and halfwave voltages of Mach-Zehnder-type optical modulators by using a small signal operation,�?? IEEE Photonics Technol. Lett. 15, 682-684 (2003).
    [CrossRef]
  4. N. Courjal and H. Porte, �??Method for measuring frequency chirping in external Mach-Zehnder modulators,�?? presented at European Conference on Integrated Optics, ECIO'03, Prague, Czek Republic, 2- 4 April 2003
  5. H. Kim and A.H. Gnauck, �??Chirp characteristics of Dual-drive Mach-Zehnder modulator with a finite DC extinction ratio,�?? IEEE Photonics Technol. Lett. 14, 298-301 (2002).
    [CrossRef]
  6. F. Koyama and K. Iga, "Frequency chirping in external modulators," J. Lightwave Technol. 6, 87-93 (1988).
    [CrossRef]
  7. F. Devaux, Y. Sorel, and J.F. Kerdiles, "Simple measurement of fiber dispersion and of chirp parameter of intensity modulated light emitter," J. Lightwave Technol. 11, 1937-1940 (1993).
    [CrossRef]

ECIO'03

N. Courjal and H. Porte, �??Method for measuring frequency chirping in external Mach-Zehnder modulators,�?? presented at European Conference on Integrated Optics, ECIO'03, Prague, Czek Republic, 2- 4 April 2003

IEEE Photonics Technol. Lett.

H. Kim and A.H. Gnauck, �??Chirp characteristics of Dual-drive Mach-Zehnder modulator with a finite DC extinction ratio,�?? IEEE Photonics Technol. Lett. 14, 298-301 (2002).
[CrossRef]

S. Oikawa, T. Kawanishi, and M. Izutsu, �??Measurement of chirp parameters and halfwave voltages of Mach-Zehnder-type optical modulators by using a small signal operation,�?? IEEE Photonics Technol. Lett. 15, 682-684 (2003).
[CrossRef]

J. Lightwave Technol.

S.K Kim, O. Mizuhara, Y.K. Park, L.D. Tzeng, Y.S. Kim, and J. Jeong, " Theoritical and experimental study of 10 Gb/s transmission performance using 1.55 m LiNbO3-Based transmitters with adjustable extinction ration and chirp," J. Lightwave Technol. 7, 1320-1325 (1999).

F. Koyama and K. Iga, "Frequency chirping in external modulators," J. Lightwave Technol. 6, 87-93 (1988).
[CrossRef]

F. Devaux, Y. Sorel, and J.F. Kerdiles, "Simple measurement of fiber dispersion and of chirp parameter of intensity modulated light emitter," J. Lightwave Technol. 11, 1937-1940 (1993).
[CrossRef]

Opt. Lett.

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 (5)

Fig. 1.
Fig. 1.

Schematic Experimental Setup.

Fig. 2.
Fig. 2.

Transversal structure of LiNbO3 modulators.

Fig. 3.
Fig. 3.

Measured optical spectra.

Fig. 4.
Fig. 4.

Frequency dependance of A1 and A2 for both modulators. Squares and circles: measured results for the X-cut and the Z-cut modulator respectively.

Fig. 5.
Fig. 5.

Frequency behavior of the απ/2 chirp parameter for X-cut modulator (experiment: squares, theory: dashed) and a Z-cut modulator (experiment: circles, theory: dotted).

Equations (17)

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

E ¯ ( t ) = E 0 × exp ( j ω o t ) × [ exp ( j A 1 × cos ( Ω t ) ) + γ × exp ( j A 2 × cos ( Ω t ) + j Δ φ DC ) ]
α = d φ dt 1 2 I ( t ) × dI dt
φ ( t ) = tan 1 ( sin ( A 1 × cos ( Ω t ) ) + γ × sin ( A 2 × cos ( Ω t ) + Δ φ DC ) cos ( A 1 × cos ( Ω t ) ) + γ × cos ( A 2 × cos ( Ω t ) + Δ φ DC ) )
I ( t ) = E 0 2 ( 1 + γ 2 + 2 × γ × cos ( ( A 1 A 2 ) × cos ( Ω t ) Δ φ DC ) )
α π 2 = A 1 + γ 2 × A 2 γ × ( A 1 A 2 )
I 0 ( ω ) = E 0 2 × ( 1 + γ ) 2 × δ ( ω ω 0 ) + E 0 2 4 × ( A 1 + γ A 2 ) 2 × δ [ ω ( ω 0 ± Ω ) ]
I π ( ω ) = E 0 2 × ( 1 γ ) 2 × δ ( ω ω 0 ) + E 0 2 4 × ( A 1 γ A 2 ) 2 × δ [ ω ( ω 0 ± Ω ) ]
γ = I 0 1 2 ( ω 0 ) I π 1 2 ( ω 0 ) I π 1 2 ( ω 0 ) + I 0 1 2 ( ω 0 )
A 1 = 2 × I 0 1 2 ( ω 0 + Ω ) + I π 1 2 ( ω 0 + Ω ) I π 1 2 ( ω 0 ) + I 0 1 2 ( ω 0 )
A 2 = 2 × I 0 1 2 ( ω 0 + Ω ) I π 1 2 ( ω 0 + Ω ) I π 1 2 ( ω 0 ) I 0 1 2 ( ω 0 )
α π 2 = I 0 1 2 ( ω 0 ) × I 0 ( ω 0 + Ω ) + I π 1 2 ( ω 0 ) · I π 1 2 ( ω 0 + Ω ) I 0 1 2 ( ω 0 ) × I π 1 2 ( ω 0 + Ω ) I π 1 2 ( ω 0 ) × I 0 1 2 ( ω 0 + Ω )
γ = J 0 ( A 2 ) J 0 ( A 1 )
α π 2 = J 0 ( A 1 ) × J 1 ( A 1 ) + γ 2 × J 0 ( A 2 ) × J 1 ( A 2 ) γ × ( J 0 ( A 2 ) × J 1 ( A 1 ) J 0 ( A 1 ) × J 1 ( A 2 ) )
I 0 ( ω ) = E 0 2 × [ J 0 ( A 1 ) + γ × J 0 ( A 2 ) ] 2 × δ ( ω ω 0 ) +
E 0 2 4 × ( J 1 ( A 1 ) + γ × J 1 ( A 2 ) ) 2 × δ [ ω ( ω 0 ± Ω ) ]
I π ( ω ) = E 0 2 × [ J 0 ( A 1 ) γ × J 0 ( A 2 ) ] 2 × δ ( ω ω 0 ) +
E 0 2 4 × ( J 1 ( A 1 ) γ × J 1 ( A 2 ) ) 2 × δ [ ω ( ω 0 ± Ω ) ]

Metrics