Waveguide laser for the far infrared (FIR) pumped by a CO2 laser

Abstract

Using a hollow waveguide resonator, laser operation in the far infrared (FIR) has been observed on several transitions between 40 and 200 μm from methyl alcohol excited by the resonant absorption of CO2 pump laser lines. The preliminary performance characteristics of FIR waveguide lasers constructed from both metallic and dielectric tubes are discussed. For CO2 pump powers of a few watts, cw output power at the milliwatt level in the FIR was observed from waveguide laser structures only a small fraction of the size of conventional FIR laser resonators.

Superradiant guided modes in flashlamp pumped capillary dye lasers

“…In waveguide gas lasers, for instance, both refractive-index and gain have normal quadratic variations. Very efficient waveguide gas laser oscillators [18][19][20][21] and amplifiers [22] have been recently reported, with very stable operation on the fundamental mode [19]. With an 'inverted' gain distribution as is our case, modes with offaxis maxima are favoured.…”

Optically Pumped Terahertz Molecular Laser: Gain Factor and Validation up to 5.5 THz

“…Only the pairs of transitions exhibiting an exploitable molecular gain factor, i.e., within five orders of magnitude of the strongest one (here G m > 1 Â 10 À21 uG m ) are reported. Under these restrictions, a total of 326 potential laser lines accessible via 808 pump/laser combinations for 14 NH 3 (Table S3, Supporting Information) and 285 potential laser lines accessible via 733 pump/laser combinations for 15 NH 3 (Table S4, Supporting Information) are reported in this work. Subsets of these tables, displaying only the THz laser lines with the strongest potential, their paired MIR pump frequency and molecular gain factor, are reported in Table 1.…”

“…[14] THz spectrometers that use such molecular lasers pumped by CO 2 lasers are usually very bulky, energy intensive, and require both a lot of different molecules to cover the THz range and a strong expertise. [1,[15][16][17][18][19] Because of their continuous tunability, solid-state pump sources overcome the aforementioned difficulty to generate the adequate frequency for a molecular gain medium. Pulsed optical parametric oscillators (OPOs) have proven efficient pump sources to generate mid-infrared (MIR) beams [20] -initiating the rise of "gas photonics" [21] -while MIR continuous-wave (CW) QCLs [22] have enabled the demonstration of the first THz molecular laser optically pumped by a solid-state laser.…”

Design and performances of a CW CH3OH waveguide laser

“…-We have used a waveguide structure. This narrow bore configuration has been the first decisive progress towards FIR laser with high power efficiency [15] since it favors the diffusion processes which generally govern the vibrational relaxation. Besides, waveguide cavities present several advantages over the Fabry-Perot cavities such as compactness and ease of alignment.…”