FIELD: physics, optics.
SUBSTANCE: filter has a light modulator, a measuring photodetector and a processor unit whose output is connected to the control input of the light modulator. The measuring input of the processor unit is connected to the output of the measuring photodetector, the aperture of which is the control input of the device. The entrance aperture of the light modulator is the data input of the device and the exit aperture of the light modulator is the output of the device. The light modulator is binary. The working cycle of the device is broken down into working intervals, the duration of each of which is equal to the sum τ1+τ2, where τ1 and τ2 denote the time at which the binary light modulator is in the open and closed states, respectively. The ratio τ1/(τ1+τ2) determines average optical transmission over a working interval. The phase during which the binary light modulator is in closed state can vary within the working interval.
EFFECT: improved light protective properties due to that the phase of the closed state coincides with the phase of the emergence of interfering short light pulses while maintaining the average optical transmission of the modulator, which enables to preserve the function of adapting the device to the average light intensity value.
4 dwg
