Faraday isolator for a 100 J/10 Hz pulsed laser

We report the first-ever, to the best of our knowledge, demonstration of the optical isolation of a kilowatt average power pulsed laser. A Faraday isolator capable of stable protection of the laser amplifier chain delivering 100 J nanosecond laser pulses at the repetition rate of 10 Hz has been developed and successfully tested. The isolator provided an isolation ratio of 30.46 dB in the course of an hour-long testing run at full power without any noticeable decrease due to the thermal effects. This is the first-ever, to the best of our knowledge, demonstration of a nonreciprocal optical device operated with such a powerful high-energy, high-repetition-rate laser beam, opening up the possibilities for this type of laser to be used for a number of industrial and scientific applications.