Let us briefly describe the operation of the functional diagram in Fig. 8.11.
Optical continuous emission of the LTI-501 laser, which output power is from
1 to 40 W, and the wavelength 1.06 μm, passes to the AOM modulator input. The
sinusoidal voltage with 1 W-power acts at the electric input of AOM from the
external oscillator “Os” (with low position of the switch Sw). The coefficient of
modulation of the laser emission intensity at AOM output in the main beam on the
1 GHz-frequency is approximately 12%.
Then the optical emission from the modulator output passes to the fiber optical
system (FOS) input. FOS consists of the fiber-optical couplers of Y-type and optical
fibers FO0, FO1, FO1,. . .FON with different length—100–4000 m. The modulated
Fig. 8.11 A structure of the phased microwave fiber-optical system (a) on the base of the powerful
laser and OEO: “Laser LTI-501” ¼ the powerful laser, “AOM” ¼ the acousto-optical modulator,
“Os” ¼ oscillator, “f” ¼ the frequency-meter, “Δφ” ¼ the phase-meter, “Sw” ¼ a switch, PD0,
PD1, PD2, PDN ¼ the respective photodetectors 0,1,2. . .N; FO0, FO1, FO2, FON ¼ the respective
optical fiber 0,1,2. . .N; “F” ¼ the RF filter, “NA” ¼ the RF amplifier. General view of the powerful
laser LTI-501 (b) and the acousto-optical modulator (c)
8.3 OEO on the Powerful Laser for the Phased Microwave RF FODL for the Active. . .
479
Optical continuous emission of the LTI-501 laser, which output power is from
1 to 40 W, and the wavelength 1.06 μm, passes to the AOM modulator input. The
sinusoidal voltage with 1 W-power acts at the electric input of AOM from the
external oscillator “Os” (with low position of the switch Sw). The coefficient of
modulation of the laser emission intensity at AOM output in the main beam on the
1 GHz-frequency is approximately 12%.
Then the optical emission from the modulator output passes to the fiber optical
system (FOS) input. FOS consists of the fiber-optical couplers of Y-type and optical
fibers FO0, FO1, FO1,. . .FON with different length—100–4000 m. The modulated
Fig. 8.11 A structure of the phased microwave fiber-optical system (a) on the base of the powerful
laser and OEO: “Laser LTI-501” ¼ the powerful laser, “AOM” ¼ the acousto-optical modulator,
“Os” ¼ oscillator, “f” ¼ the frequency-meter, “Δφ” ¼ the phase-meter, “Sw” ¼ a switch, PD0,
PD1, PD2, PDN ¼ the respective photodetectors 0,1,2. . .N; FO0, FO1, FO2, FON ¼ the respective
optical fiber 0,1,2. . .N; “F” ¼ the RF filter, “NA” ¼ the RF amplifier. General view of the powerful
laser LTI-501 (b) and the acousto-optical modulator (c)
8.3 OEO on the Powerful Laser for the Phased Microwave RF FODL for the Active. . .
479