Apparatus for producing tunable intense coherent radiation in the

Abstract

Apparatus for producing tunable intense coherent radiation at approximately 628 cm..sup.-1 with a line width less than 0.1 cm..sup.-1. The apparatus includes an optical cavity containing a vapor cell and pumping means including at least one optical pumping source for directing energy at the cavity. In one embodiment the cavity encloses a material capable of stimulated emission in response to said pumping. The material has at least three atomic energy levels with at least a first and second atomic energy level separated by a particular energy quantum approximately equal to 628 cm.sup.-1 ; a transition from said first to said second atomic energy level favored over all other possible transitions from said first atomic energy level; said third atomic energy level, from which atoms can be pumped to said first atomic energy level in response to said pumping means. While this is consistent with classical laser operation the apparatus disclosed herein can also be used for stimulated Raman scattering. Tunability is achieved by tuning the pumping sources in the case of stimulated Raman scattering, or with the aid of the Zeeman or Stark effects for classical laser operation. Typical materials are potassium or strontium vapors. Several pumping arrangements are also disclosed.