are obtained in this chapter taking into account the optical power in the MZ optical
channels.
We note that phase noises exceeds the amplitude noises by 10–25 dB/Hz, and the
natural value of the resonance peak increases by almost the order with the growth of
values of the pumping current exceed from three to seven.
Figures 6.35 and 6.36 show the calculated functions of PSD of the phase noise of
RF oscillations in OEO MZ S(F) versus the offset F from the carrier. At that, the
width of the spectral line of the high-coherent laser is Δv ¼ 10 kHz, 1 kHz, 5 kHz,
100 kHz, and 1000 kHz (the observation time is 1 ms). The optical fiber length is
L ¼ 6 km, the generation frequency is 10 GHz. The excitation coefficient of the
optical channel OC2 is К 02 ¼ 0.499.
From plots presented in Figs. 6.35 and 6.36, we can conclude that the variation of
laser spectral line width from 1 to 1000 kHz leads to increase of PSD of the phase
noise at frequency offsets by 1–10 kHz more than by 30 dB/Hz. It is specially
necessary to note the increase of PSD of the phase noise on the frequency offsets,
which corresponds to the frequency of the photon–electron resonance F 1
(in Fig. 6.36).
The functions presented in Fig. 6.36 well explain the complicated picture of PSD
of the phase noise added by the electron–photon resonance of QWLD. In experimental samples of OEO MZ, we see the clearly expressed resonance peak on the
frequency offset from the RF carrier of 10 GHz. First of all, the position of the
Fig. 6.36 Calculated PSD of the phase noise of RF oscillations in OEO MZ S( f ) for different
values of the laser spectral line width. The width of the laser spectral line of the high-coherent laser
is Δv ¼ 1 kHz (curve 1), 10 kHz (curve 2), 100 kHz (curve 3) and 1000 kHz (curve 4) (the
observation time is 1 ms). The curve PD-Y corresponds to the own PSD of the phase noise of
PD. The optical fiber length is L ¼ 6 km, the generation frequency is 10 GHz. FOS consists of three
optical fibers of different lengths connected by the Y-couplers. Owing to utilization of the
composite FOS from three optical fibers of different lengths, we can decrease the level of spurious
harmonic components
362
6 Operation Analysis of Optoelectronic oscillator (OEO) with External. . .
channels.
We note that phase noises exceeds the amplitude noises by 10–25 dB/Hz, and the
natural value of the resonance peak increases by almost the order with the growth of
values of the pumping current exceed from three to seven.
Figures 6.35 and 6.36 show the calculated functions of PSD of the phase noise of
RF oscillations in OEO MZ S(F) versus the offset F from the carrier. At that, the
width of the spectral line of the high-coherent laser is Δv ¼ 10 kHz, 1 kHz, 5 kHz,
100 kHz, and 1000 kHz (the observation time is 1 ms). The optical fiber length is
L ¼ 6 km, the generation frequency is 10 GHz. The excitation coefficient of the
optical channel OC2 is К 02 ¼ 0.499.
From plots presented in Figs. 6.35 and 6.36, we can conclude that the variation of
laser spectral line width from 1 to 1000 kHz leads to increase of PSD of the phase
noise at frequency offsets by 1–10 kHz more than by 30 dB/Hz. It is specially
necessary to note the increase of PSD of the phase noise on the frequency offsets,
which corresponds to the frequency of the photon–electron resonance F 1
(in Fig. 6.36).
The functions presented in Fig. 6.36 well explain the complicated picture of PSD
of the phase noise added by the electron–photon resonance of QWLD. In experimental samples of OEO MZ, we see the clearly expressed resonance peak on the
frequency offset from the RF carrier of 10 GHz. First of all, the position of the
Fig. 6.36 Calculated PSD of the phase noise of RF oscillations in OEO MZ S( f ) for different
values of the laser spectral line width. The width of the laser spectral line of the high-coherent laser
is Δv ¼ 1 kHz (curve 1), 10 kHz (curve 2), 100 kHz (curve 3) and 1000 kHz (curve 4) (the
observation time is 1 ms). The curve PD-Y corresponds to the own PSD of the phase noise of
PD. The optical fiber length is L ¼ 6 km, the generation frequency is 10 GHz. FOS consists of three
optical fibers of different lengths connected by the Y-couplers. Owing to utilization of the
composite FOS from three optical fibers of different lengths, we can decrease the level of spurious
harmonic components
362
6 Operation Analysis of Optoelectronic oscillator (OEO) with External. . .