The waveguide laser: A review

Abstract

The present article reviews the fundamental physical principles essential to an understanding of waveguide gas and liquid lasers, and the current technological state of these devices. At the present time, waveguide laser transitions span the visible through submillimeter regions of the wavelength spectrum. The introduction discusses the many applications of waveguide lasers and the wide variety of laser configurations that are possible. Section 1 summarizes the properties of modes in hollow dielectric waveguides of circular, rectangular, and planar cross section. Section 2 considers various approaches to optical feedback including internal and external mirror Fabry-Perot type resonators, hollow waveguide distributed feedback structures, and ring-resonant configurations. Section 3 discusses those aspects of molecular kinetic and laser theory pertinent to the design and optimization of waveguide gas lasers such as the scaling laws for discharge-excited gas lasers, molecular models useful in maximizing the oscillation bandwidth, the effects of gas flow rate, and the physics of optically-pumped far-infrared lasers. Finally, a review of the waveguide gas and liquid lasers reported to date is given in Section 4.