OEO base belongs to authors of this book and it was mentioned for the first time in
publication in 2004 and 2005 on the international conference “Radio-optical technologies-2004” [7].
8.5.3 OEO Utilization for Measurement of PSD of Phase
Noises in Oscillators, Microwave and mm-Wave Devices
and Lasers with the Narrow Spectral Line Below
100 kHz
One of the OEO application (with the close and open feedback loop) is in the
measuring workbenches for the phase noise analysis in microwave and mm-wave
oscillators with the extremely low level of minimally measured noises of À130 dB/
Hz at 10 GHz-frequency and 1 kHz-offset. At that, OEO is used as the reference
oscillator with low phase noises, and in this case, the OEO feedback loop is closed.
One of OEO advantages, which have optical and electronic outputs, is application
of the low-noise fiber-optical retarded system with the time delay more that 50 μs
without the additional electro-optical converter in devices of the phase noise measurement. Prospects of this method utilization for phase noise measurements are
improved with development of the wideband Mach–Zehnder modulators with bandwidth up to 50 GHz. The potential measurement limit with the help of composite
compensating Mach–Zehnder modulators and utilization of lasers with the line
width less than 1 kHz can be decreased down to À160 dB/Hz.
From commercial point of view, this method is more beneficial compared to
application of expensive low-noise oscillators with the sapphire resonator.
8.5.4 OEO Application in Lengthy Fiber-Optical Links
of the Secretive Communication with the Increased
Noise Immunity
The main principle of these systems’ construction consists in the masking of
message transmission with the help of useful information introduction into chaotic
carrier [8]. The reverse information extraction at the unauthorized access, i.e., at
absence of a-priori data about the initial dynamic system, is quite difficult, and in
some condition, is practically impossible. Thus, the chaotic signal is indistinguishable with high probability from the random interference for the external observer,
which allows hiding of the transmission fact itself. At detection, the procedure of
information extraction itself essentially complicates by the traditional methods,
which provides high confidence of transmitted data.
Application of OEO chaotic oscillations for information transmission through the
fiber optical communication links is defined, firstly, by relative simplification of the
494
8 Experimental Investigations and Practical Circuits of Optoelectronic. . .
publication in 2004 and 2005 on the international conference “Radio-optical technologies-2004” [7].
8.5.3 OEO Utilization for Measurement of PSD of Phase
Noises in Oscillators, Microwave and mm-Wave Devices
and Lasers with the Narrow Spectral Line Below
100 kHz
One of the OEO application (with the close and open feedback loop) is in the
measuring workbenches for the phase noise analysis in microwave and mm-wave
oscillators with the extremely low level of minimally measured noises of À130 dB/
Hz at 10 GHz-frequency and 1 kHz-offset. At that, OEO is used as the reference
oscillator with low phase noises, and in this case, the OEO feedback loop is closed.
One of OEO advantages, which have optical and electronic outputs, is application
of the low-noise fiber-optical retarded system with the time delay more that 50 μs
without the additional electro-optical converter in devices of the phase noise measurement. Prospects of this method utilization for phase noise measurements are
improved with development of the wideband Mach–Zehnder modulators with bandwidth up to 50 GHz. The potential measurement limit with the help of composite
compensating Mach–Zehnder modulators and utilization of lasers with the line
width less than 1 kHz can be decreased down to À160 dB/Hz.
From commercial point of view, this method is more beneficial compared to
application of expensive low-noise oscillators with the sapphire resonator.
8.5.4 OEO Application in Lengthy Fiber-Optical Links
of the Secretive Communication with the Increased
Noise Immunity
The main principle of these systems’ construction consists in the masking of
message transmission with the help of useful information introduction into chaotic
carrier [8]. The reverse information extraction at the unauthorized access, i.e., at
absence of a-priori data about the initial dynamic system, is quite difficult, and in
some condition, is practically impossible. Thus, the chaotic signal is indistinguishable with high probability from the random interference for the external observer,
which allows hiding of the transmission fact itself. At detection, the procedure of
information extraction itself essentially complicates by the traditional methods,
which provides high confidence of transmitted data.
Application of OEO chaotic oscillations for information transmission through the
fiber optical communication links is defined, firstly, by relative simplification of the
494
8 Experimental Investigations and Practical Circuits of Optoelectronic. . .