Dadashzadeh, NedaThirugnanasambandam, Manasadevi P.Weerasinghe, H. W. KushanDebord, BenoitChafer, MatthieuGerome, FredericBenabid, FetahWashburn, Brian R.Corwin, Kristan L.2020-06-172020-06-172017-06-12https://hdl.handle.net/2097/40717We investigate the mid-IR laser beam characteristics from an acetylene-filled hollow-core optical fiber gas laser (HOFGLAS) system. The laser exhibits near-diffraction limited beam quality in the 3 μm region with M2 = 1.15 ± 0.02 measured at high pulse energy, and the highest mid-IR pulse energy from a HOFGLAS system of 1.4 μJ is reported. Furthermore, the effects of output saturation with pump pulse energy are reduced through the use of longer fibers with low loss. Finally, the slope efficiency is shown to be nearly independent of gas pressure over a wide range, which is encouraging for further output power increase.This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).Fiber lasersGas lasersHollow core fibersLaser beam characterizationText