Tsis ntev los no, lub chaw nyob hauv Russell rau kev tshawb fawb teeb pom kev zoo ntawm Kev Tshawb Fawb thiab Tshuab Shanghai of Science, LTIZE}, LTD {{}}}} Thoob ntiaj teb Kev Ua Si Thoob Ntiaj Teb "Optica, thiab thawj zaug ntawm Femtoseconds, 2}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}} Qhov txiaj ntsig no tsis tsuas yog muab txoj kev daws teeb meem zoo rau qhov tsis txaus ntseeg ntawm Mid-Infrared Ultrafast Pulses hauv kev sib kis tau, tab sis kuj lays lub hauv paus rau kev nthuav dav ntawm nruab nrab ntawm nruab nrab daim ntawv thov laser
High-power mid-infrared ultrafast broadband light sources have important applications in advanced spectroscopy, material fine processing, medical surgery, and remote sensing. The limitations of laser transmission have hindered the further expansion of mid-infrared laser applications. In traditional transmission methods, the absorption of various gas molecules in the spatial optical path causes deformation of the output light spot and deterioration of pulse quality. Solid mid-infrared optical fiber has serious nonlinear accumulation, which causes serious distortion of the output time-frequency signal. To solve this problem, the research team used a self-made single-hole eight-ring structure Hollow-core PCF (length 5 m) to transmit mid-infrared ultrafast pulses. Thanks to the advantages of low transmission loss, low nonlinear effect accumulation and support for rapid vacuum extraction of Hollow-core PCF, the team not only solved the problems caused by traditional transmission methods, but also successfully achieved efficient transmission with an overall efficiency of >70%.
During the experiment, the experimenters used a self-built mid-infrared pulse fiber laser as the light source and a 5 m long Hollow-core PCF as the transmission medium. The two ends of the Hollow-core PCF were fixed in the air chamber so that the Hollow-core PCF could be evacuated using a vacuum pump. After the vacuum was drawn (the entire extraction process took less than 1 minute, and the gas pressure was drawn to ~10 mbar), the team successfully achieved an overall laser efficiency of > 70%, a Gaussian spot output that was close to the diffraction limit, and the entire system showed excellent stability. In addition, the spectral shape of the output in the frequency domain was basically consistent with the input. In the time domain, due to the small amount of waveguide dispersion of the hollow-core PCF (-2.04 fs2/mm @ 2.8 μm), the pulse width was widened from the input 117 fs to 404 fs. Subsequently, the experimenters added Ge and ZnSe positive dispersion materials to compensate for the negative dispersion introduced by the hollow-core PCF, coupling lens and air chamber window, and obtained an output with a pulse width of 98 fs (close to the transformation limit pulse width of 96 fs), with a peak power of 170 kW. In addition, the experimenters also used the autocorrelation trace to estimate that the output fundamental mode energy accounted for >95%.
Cov kws sim kuj piv rau cov kab mob sib txawv ntawm cov pulses thiab cov tsis muaj zog pom ntawm cov pulses thiab cov lus pom tseeb zoo nkauj, uas yog qhia txog qhov tshwj xeeb ntawm hollow-core photonic Crystal fibers nyob rau hauv kev kis tau lub zog siab Mid-Infrared Ulforic Pulity FineTes hauv Spectroscopy, infrared countermeasures thiab chaw taws teeb Hnov .
Cov kev tshawb fawb tshwj xeeb tau tshaj tawm hauv cov ntawv sau xov xwm saum toj kawg nkaus ntawm kev nqus dej, 100 folls) Thev naus laus zis, thiab cov kws sau ntawv ntawm Shanghai of Optics thiab cov kws sau ntawv zoo, thiab cov kws sau npe sib tw, yog Coedell
Daim duab 1.}}}} {{1} {}} lens, coated caf2 plano-conve; HWP, ib nrab yoj phaj; QWP, lub quarter-yoj phaj phaj; Fm, khoov daim iav; Ftir, Filier Transform Infraromed Spectrometer; AC, autocorrelator . (B) SEM cov qauv uas siv lub zog tsis txaus ntseeg (d)} (d)} Hollow-Core core pcf. (e) Siv 30 hli GEs thiab 5 mma pulse-transty-transmes-transformation-transformation-hloov pauv ntawm 98 FS tau tiav.
Daim duab 2. sib piv ntawm cov khoom siv sib txawv ntawm cov pa hluav taws xob (ntsuab) thiab kis tus tub ceev xwm (liab) . ib sab sab xis qhia tau cov khoom siv fluoride ntau tshaj}} {} {{{.
