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In order to study the saturation threshold and the
image jamming effect of wavelength, energy or
power, frequency and size of laser spot, the laser
saturation jamming experiments by means of
diffuseness are developed, in which, CO2 tunable
pulse laser and CO2 continuous wave(CW) laser
separately interfere HgCdTe 288×4 cooled
scanning IR imaging system and microbolometer
poly-Si 320×240 Uncooled Focal Plane
Array(UFPA) staring IR imaging system. The
jamming effect is reflected through the
output-images of the IR imaging system. Therefore,
when the experiments were developing, with the
minishing of the laser beam attenuation, the energy
or power density of the laser was augmented.
Simultaneously, with the density of laser spot
changing, the changes of output-images had also
taken place. The output-images of the IR imaging
system were also observed, collected and saved.
Moreover, by adjusting the laser's energy density,
the saturation threshold was tested. Furthermore,
by adjusting the laser's energy or power density,
wavelength, frequency and size of laser spot, the
image jamming effect of IR imaging system
induced by CO2 laser was studied. In the
experiments of the size of laser spot's to jamming
effect, on the premise of the laser energy being
invariable, with the laser spot enlarging, on the
contribution to jamming effect, the added
interfered image elements compensate the loss to
jamming effect due to energy descending and
exceed it. In the experiments of the frequency to
jamming effect, when the jamming laser works
with higher repeating frequency, after the
interference is stopped, the resume time of IR
imaging system is more than it of laser working
with monopulse interference. Within settled time,
much impulses engender accumulation of energy
in detector, which correspond to improving the
laser's intensity at the jamming effect angle. So,
the jamming effect of IR image system is rightly
proportional to intensity of interference laser. And
improving jamming laser's frequency is propitious
to jamming effect of IR image system. In the
experiments of CO2 tunable pulse laser interfering
HgCdTe 288×4 cooled scanning IR imaging
system, the jamming effect of pulse laser is
unconspicuous. On the contrary, the CW laser's
jamming effect is conspicuous. This also have
something to do with the responding wave band of
IR imaging system. The all results are analyzed
through analyzing the jamming images, and they
show that the jamming effects are improved with
energy, frequency, wavelength and size of laser
spot increasing. Otherwise, the jamming effect
proves that the jamming means of diffuseness is
feasible.
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