Analogue transmission at 1.55 µm using linearised electroabsorption modulator/DFB laser and fibre amplifier

Large Signal Analysis of the Dual-Parallel Electroabsorption Modulator

“…Inspection of Figure 2 clearly shows that the polarity of the amplitude of the output intermodulation product of frequency 2ω 1 − ω 2 is strongly dependent on the EAM parameters α 1 Thus, it appears that, although a biasing scenario for the parallel EAM structure of Figure 1 may result in reduced amplitudes of the output third-order intermodulation products under specific RF modulation index m i , the same scenario may fail to reduce intermodulation products by the same amount if the RF modulation index is changed. This is attributed to the fact that in an EAM, characterized by Equation (1), the thirdorder intermodulation products are not generated by a single term, but by the summation of several terms sharing the same spectral lines as shown in Table 2.…”

“…This is attributed to their low driving voltage operation, large bandwidth, and the feasibility of monolithic integration with laser diodes [1][2][3][4][5][6]. According to Chen [3] the transfer function of the EAM can be expressed by…”

Large Signal Performance of the Electroabsorption Modulator

“…Term type r ± s Term type 2 r ± s Term type r ± s ± q Table 5 Intermodulation products sharing same spectral line with frequency 2ω 1 Term type r ± s Term type 2 r ± s Term type r ± s ± q 5 + 6 None 1 + 2 + 5 1 − 2 + 6 Table 6 Intermodulation products sharing same spectral line with frequency 3ω 1 Term type r ± s Term type 2 r ± s Term type r ± s ± q…”

“…This is attributed to their low driving voltage operation, large bandwidth and the feasibility of monolithic integration with laser diodes [1][2][3][4][5][6][7][8][9]. According to Chen [6] the transfer function of the EAM can be expressed by…”

Predistortion of electroabsorption modulators for analog CATV systems at 1.55 μm

“…Integrated electroabsorption modulated lasers (EML's) [3] also have low chirp, are compact, and potentially cost less. Transmission through nondispersion-shifted fiber, without dispersion compensation and with negligible penalty, has been demonstrated, both using a linearized EML [4] and a linearized discrete electroabsorption (EA) modulator [5].…”