Hermite-Gaussian modes in geometrically unconfined resonators with a four-level system saturable gain guide inside are experimentally observed and proved. The gain guide was formed with a polished cylindrical surface low-concentration Nd:YAG rod exposed to isotropic pump radiation. The connection of the mode scaling factor with the system parameters is compared with the theory. The abilities of the recently established gain-saturation guiding mechanism to support the generation of beams with wide tops and rapidly decreasing intensity in the wings are also experimentally proved. Application areas for saturable gain guiding are briefly discussed.
© 2002 Optical Society of America
Original Manuscript: January 2, 2001
Revised Manuscript: July 16, 2001
Published: March 20, 2002
Ognian Denchev, Stoyan Kurtev, and Plamen Petrov, "Experimental investigation of saturable gain-guided modes," Appl. Opt. 41, 1677-1684 (2002)