Single wall carbon nanotubes and their conjugates with dimeric phthalocyanine complexes of Cu for optical limiters in the protection of photosensitive detectors and micro-optoelectromechanical systems

To protect photosensitive detectors and micro-optoelectromechanical systems, protective equipment is needed against the ingress of powerful laser radiation. Conventional color filters pose a problem for such devices by cutting out the region of the spectrum in which the laser operates. To ensure the possible operation, passive limiters based on nonlinear optical effects can be used. They are capable of transmitting non-hazardous laser radiation with insignificant attenuation (transmission of the order of 70%), and when hit by powerful laser radiation they can quickly darken. The urgency of this problem only increases with the development and widespread use of laser systems. In particular, when using lidars, receiving photosensitive detectors are often damaged. The use of various conjugates with carbon nanotubes is promising for creating limiters. In this work, it is proposed to use conjugates of dimeric phthalocyanine complexes of Cu to create nonlinear optical materials. This material demonstrates the ability to attenuate laser radiation with a nanosecond duration of 16 ns, even in the case of single pulses, due to the synergistic effect of absorption and scattering of radiation. In addition, in the case of 140 fs femtosecond periodic radiation, with a pulse repetition rate of 80 MHz, this material demonstrates the attenuation of radiation when using a cut-off diaphragm due to the effect of self-phase modulation (SSPM). The characteristics of the SSPM pattern were studied, it was noted that the outer rings have the greatest width. In general, the width of the rings gradually increases with distance from the center of the beam. At the same time, the peak fluence (highest fluence value) of each ring is approximately the same, with the exception of the central part. In the central region, a strong effect is observed from heated flows tending upward and thus strongly violating symmetry.