Page 387 - Fiber Bragg Gratings
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364                        Chapter 8 Fiber Grating Lasers and Amplifiers

         ramped from threshold to 100 mA without a mode hop, and with a wave-
         length change of only 0.1 nm [24].
             The static and dynamic chirp measurements of 500-yitm-long AR-coated
                            5
         (reflectivity ~1 X 10~ ) angled facet GaAsPInPburied-heterostructure am-
         plifier chips [24] show that the static chirp of the dominant FGL mode is
         —0.06 GHz/mA, while the dynamic chirp is reduced to 0.016 GHz/mA. The
         fiber Bragg grating had a reflectivity of 30% with a FWHM bandwidth of
         0.3 nm. This data is shown in Figs. 8.7a and 8.7b. This laser has also been
















         Figure 8.7: (a) Static chirp of external cavity and FP modes of the FGL; (b)
         shows the dynamic chirp under active modulation (from: Timofeev F. N., Bayvel
         P., Mikhailov V., Lavrova O. A., Wyatt R., Kashyap R., Robertson M. and Midwinter
         J. E., "2.5 Gbit/s directly modulated fibre grating laser for WDM networks", Elec-
         tron. Lett., 33(16), 1406-1407, July, 1997. © IEE 1997, Ref. [30]).

















         Figure 8.8: The kink-free light output characteristics of an angled-facet FGL
         with a 7-mm external cavity, as a function of temperature. Measured side-mode
         suppression ratio is —45 dB and RIN is —145 dB/Hz (from: Timofeev F. N., Bayvel
         P., Mikhailov V., Lavrova O. A., Wyatt R., Kashyap R., Robertson M. and Midwinter
         J. E., "2.5 Gbit/s directly modulated fibre grating laser for WDM network", Elec-
         tron. Lett., 33(16), 1406-1407, July 1997. © IEE 1997, Ref. [30]).
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