• Propagation in the separate light guiders FOS0, FOS1 and FOS2 of the single
linear-polarized light wave, optical frequency of which is equal to ν L
• Application of the usual oscillating circuit as the filter
the differential equations with delay are given as:
T F
dU t
ð Þ
dt
¼ R AS 1 U t À t 1
ð
Þcos Φ 1
ð Þ þ BS 2 U t À t 2
ð
Þcos Φ 2
ð Þ
½
Š À U t
ð Þ, ð7:43Þ
T F U t
ð Þ
dΨ t
ð Þ
dt
¼ R ÀAS 1 U t À t 1
ð
Þsin Φ 1
ð Þ þ BS 2 U t À t 2
ð
Þsin Φ 2
ð Þ
½
Š
þ ω F À ω 0
ð
Þ T F U t
ð Þ,
ð7:44Þ
Here Ф 1 , Ф 2 are current phase incursions, Φ 1 ¼ τ Á (ω eF À ω 0 ) À Ψ(t) + Ψ(t À t 1 ),
Φ 2 ¼ τ Á (ω F À ω 0 ) À Ψ(t) + Ψ(t À t 2 ), t 1 ¼ [(T 1FOS + T 2FOS )/2] À (T 1FOS À T 2FOS )/2,
t 2 ¼ [(T 1FOS + T 2FOS )/2] + (T 1 À T 2 )/2, τ ¼ (T 1FOS À T 2FOS )/2, S 1 ¼ S[U(t + t 1 )], ω eF ,
T eF are the natural frequency and time constant of the RF circuit (the filter),
relatively; S 2 ¼ S[U(t À t 2 )]; T ¼ (T 1FOS + T 2FOS )/2, ω 0 is the reference frequency
of oscillations; R is the module of the controlled resistance on the frequency closed
Fig. 7.21 The functional structure of OEO with the differential RF FODL and directional couplers
of Y and X-types
410
7 Optoelectronic oscillator (OEO) as the Time and Spatial Correlator of Random. . .