Interferometric studies of coherence in a powder laser

Longitudinal and transversal coherence in powder laser emission was studied using two different interferometric techniques. It has been shown that lon gitudinal coherence length in Nd0.5La0.5Al3(BO3)(4) powder (ceramics) laser emission corresponds to 0.7 Angstrom linewidth. This value is in agreement with the results of direct spectroscopic linewidth measurements published in the literature. The transversal coherence has not been shown to be notic eable when the distance between two points on the emitting surface is equal to approximate to 85 mu m. The possible explanation of the result obtained is discussed. (C) 1999 Elsevier Science B.V. All rights reserved.