We study the optical discharge in air in the presence of an absorbing carbon particle under the action of Nd laser radiation at the wavelength of 1.06 mkm. Formation of secondary particles has been detected; these particles having the size from 0.01 to 1.2 mkm were generated in the processes of fragmentation, recondensation, and others. The particle size distribution histogram has been constructed based on microphotos. The dependence of the squared speed of the discharge front on the energy deposition has been found. The electron concentration has been determined using an electric sonde. The amplitude of pressure in the sonic wave is estimated.