The Gaussian Mode in Optical Resonators With a Radial Gain Profile

Abstract

The dependence of the parameters of the Gaussian mode in laser resonators on the properties of the medium in the cavity is studied. Experimental verification of the theoretical results is presented. It is found that the modes in a high-gain laser may differ widely from the usual free space resonator results. Also, resonator configurations which in free space are unstable may, with a suitable medium, support low-loss Gaussian modes.

Off-axis multimode light beam propagation in tapered lenslike media including those with spatial gain or loss variation

“…The theory presented here applies to systems with gain. The predictions made by the theory agree well with experiment [18]. This study is primarily concerned with tapered media.…”

“…Near the center, cubic and higher order terms can be shown to be negligible. Hence, the spatial behavior of many high power gas lasers may be approximated by a quadratic-index profile [18]. As previously suggested, a hyperbolic secant index profile can be shown to produce ideal images [12].…”

Gain and Dispersion Focusing in a High Gain Laser

“…The transverse modes of a laser resonator containing a high gain medium are most easily found using complex beam matrices. 2 In the remainder of this paper we consider only the simplest type of high gain laser, which consists of a plane parallel resonator filled with a lenslike medium. Such a configuration can be well approximated in practice.…”

“…2 A positive index profile results in a spot size of an unmatched beam which oscillates periodically with distance, while a positive gain profile causes the beam to approach a steady-state spot size. In a high gain gas discharge there is often a strong profile of the gain, so that gain focusing is likely to be important.…”

Beam Modes of Lasers with Misaligned Complex Optical Elements

“…Though the existence of nonuniform transverse gain in laser amplifiers is often inevitable, the effect may sometimes be exploited in modern optical system design. For example, in high gain Xe and He-Xe lasers [1] and subsequently in double heterostructure GaAs lasers [229], the transverse gain profile has been used to simplify resonator design.…”