Astrophysical lasers

A review of lasers operating under natural astrophysical conditions is presented. A principal difference between the conditions for obtaining inversion and amplification in an astrophysical laser and in well-known astrophysical masers is considered. The data for a recently discovered Fe II ion astrophysical laser are presented. The parameters of the astrophysical laser amplifier are discussed and the possibility of its conversion into the astrophysical laser with the incoherent feedback is considered, as well as the methods for studying the width of the emission spectrum of the astrophysical laser. (special issue devoted to the 80th anniversary of academician n g basov's birth)