component (E 12L )
2 . We must take into account that on the PD area, the AC
component of intensity is present on the background of DC component.
Let us introduce coefficients a 0 , a 1 , a 2 : a 0 ¼
E
2
0L
2 γ
1þγ
2
ð
Þ
2γ
À cos φ 0MZ
ð
ÞÁ 1 À
x
2
4
!
; a 1 ¼ À
E
2
0L
4 γ sin φ 0MZ
ð
Þ; a 2 ¼ À
E
2
0L
8 γ cos φ 0MZ
ð
Þ. Taking into account that I PD ¼
S PD Á E L12 Á E
Ã
L12
À
Á
and introducing ϕ 0eMZ , which is total phase incursion of the
photocurrent, we get following expressions for photocurrent harmonics:
I 0PD ¼ a 0 À (a 2 /2)x
2 ; I 1PD ¼ a 1
x
2 À
x
3
16
Á cos 2πft þ ϕ 0eMZ
ð
Þ ; I 2PD ¼ a 2 x
2 cos
2 (πft +
ϕ 0eMZ ). As we see, at the choice of φ 0MZ (U 0MZ ) ¼ mπ/2, m ¼ Æ1, Æ2, . . ., the function
Fig. 3.16 The spectrum of
optical harmonics in the
optical channel of OEO with
MZ at modulation index
x ¼ U 1MZ /U 0MZπ ¼ 1 (a).
The values of Bessel
functions of differential
orders, which are defined the
harmonic amplitudes at
variation of the modulation
index (b). The spectrum of
optical harmonics in the
optical channel of OEO MZ
at the modulation index
x ¼ U 1MZ /U 0MZπ ¼ 2.4 (a).
(c) The vector presentation
of EMF amplitude
summation on PD: without
selection of the optical
harmonic (d), with
summation of two side
harmonics at carrier
suppression (e), with
summation of carrier and
one of side harmonics (f)
3.2 Methods of Modulation and Heterodyning of Laser Emissions at DM and MZ. . .
107
2 . We must take into account that on the PD area, the AC
component of intensity is present on the background of DC component.
Let us introduce coefficients a 0 , a 1 , a 2 : a 0 ¼
E
2
0L
2 γ
1þγ
2
ð
Þ
2γ
À cos φ 0MZ
ð
ÞÁ 1 À
x
2
4
!
; a 1 ¼ À
E
2
0L
4 γ sin φ 0MZ
ð
Þ; a 2 ¼ À
E
2
0L
8 γ cos φ 0MZ
ð
Þ. Taking into account that I PD ¼
S PD Á E L12 Á E
Ã
L12
À
Á
and introducing ϕ 0eMZ , which is total phase incursion of the
photocurrent, we get following expressions for photocurrent harmonics:
I 0PD ¼ a 0 À (a 2 /2)x
2 ; I 1PD ¼ a 1
x
2 À
x
3
16
Á cos 2πft þ ϕ 0eMZ
ð
Þ ; I 2PD ¼ a 2 x
2 cos
2 (πft +
ϕ 0eMZ ). As we see, at the choice of φ 0MZ (U 0MZ ) ¼ mπ/2, m ¼ Æ1, Æ2, . . ., the function
Fig. 3.16 The spectrum of
optical harmonics in the
optical channel of OEO with
MZ at modulation index
x ¼ U 1MZ /U 0MZπ ¼ 1 (a).
The values of Bessel
functions of differential
orders, which are defined the
harmonic amplitudes at
variation of the modulation
index (b). The spectrum of
optical harmonics in the
optical channel of OEO MZ
at the modulation index
x ¼ U 1MZ /U 0MZπ ¼ 2.4 (a).
(c) The vector presentation
of EMF amplitude
summation on PD: without
selection of the optical
harmonic (d), with
summation of two side
harmonics at carrier
suppression (e), with
summation of carrier and
one of side harmonics (f)
3.2 Methods of Modulation and Heterodyning of Laser Emissions at DM and MZ. . .
107