Dènyèman, Russell Center pou avanse Lightwave Syans nan Hangzhou Enstiti pou Optik ak Fine Mekanik, Nasyonzini University of Science and Technolog Entènasyonal tèt jounal optik "Optica", ak la pou premye fwa reyalize segondè-efikasite, wo-fidelite a ak segondè sèl-mòd pite transmisyon fleksib nan tou pre-Watt-nivo, dè santèn de femtoseconds, 2 . 8 μM pulsasyon nan mitan-enfrawouj nan fib-nwayo fotonik kristal (Hollow-Hollow-Ow-). Rezilta sa a pa sèlman bay yon solisyon efikas nan enpèfeksyon yo nan mitan-enfrawouj pulsasyon ultra nan transmisyon, men tou, ponn fondasyon an pou ekspansyon nan mitan-enfrawouj aplikasyon lazè lazè
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%.
Ekspersateur yo tou konpare konplo a transmisyon ak chemen an espasyal optik nan menm longè a ak solid-nwayo fib la fliyò . rezilta yo montre ke pandan transmisyon an nan pulsasyon ultrafast nan solid-nwayo fib fliyò, efè a linear se twò fò, ki kapab lakòz nan tan-domèn nan pulsasyon nan pulsasyon yo ak yon moun ki gen bon-yo ki gen yon moun ki gen yon moun ki gen yon moun ki gen yon moun ki gen anpil, ki kapab lakòz yon moun ki gen yon moun ki gen yon ti kras, ki kapab lakòz yon moun ki gen bon jan ak yon moun ki gen yon moun ki gen bonjan, sa ki te fèt nan yon moun ki gen yon moun ki gen bon jan, ki te fèt, ki te lakòz yon moun ki gen yon ti tan, sa ki te fèt nan yon moun ki gen anpil tan ki gen pou yo fè sa, yo te gen yon bagay ki gen pou yo fè yon ti tan, ki te fèt nan yon moun ki te gen yon moun ki gen anpil moun ki gen yon bagay ki gen anpil moun ki gen yon bagay ki gen pou yo fè yo. fotonik kristal fib nan transmisyon an nan gwo-pik pouvwa mitan-enfrawouj pulsasyon ultrafast . eksperyans lan reyalize-wo efikasite, wo-fidelite ak wo-yon sèl-mòd pite mitan-enfrawouj lazè transmisyon teknoloji, infarded infarted infarded seprés. Kèk .
Rezilta rechèch ki enpòtan yo te pibliye nan jounal an tèt lazers ak optoelectronics, Optica, ak tit la "livrezon fleksib nan bande, 100 fs mitan-enfrawouj pulsasyon nan gwoup la dlo-absòpsyon lè l sèvi avèk Hollow-nwayo fotonik Fib kristal" {{} Teknoloji, ak Li Zeqing, yon elèv doktora nan Shanghai Enstiti pou optik ak mekanik amann, yo se otè yo ko-premye, ak Huang Jiapeng, Jiang Xin ak Pang Meng nan Russell Center a se otè yo ko-koresponn .
Figi 1. Enstalasyon eksperimantal ak rezilta . (a) eksperimantal chemen optik . lantiy, kouvwi CAF2 plano-konvèks lantiy; HWP, mwatye onn plak; QWP, trimès-onn plak; FM, Bend glas; FTIR, Fourier transfòme spèktromètr enfrawouj; Ac, otokorrelatè . (b) SEM imaj nan estrikti a fib . (c) Pèt spectre mezire lè l sèvi avèk metòd la twonke, zòn nan fonse reprezante ensèten mezi a (zoranj, aks gòch), ak koub la kalkile nan yon koub ({{{{{ Hollow-nwayo PCF . (e) Sèvi ak 30 mm ZNSE ak 5 mm materyèl GE, yon pwodiksyon batman kè ak yon lajè ki tou pre-transfòmasyon ki limite nan 98 FS te reyalize .
Figure 2. Comparison of different transmission modes. (a) Normalized absorption spectrum of water vapor. (b) Direct laser output (gray) and transmission spectrum in the spatial optical path (purple), transmission spectrum of hollow-core PCF in air (green), and transmission spectrum of hollow-core PCF in vacuum (wouj) . bò dwat la montre spectre la elaji nan seri a nan 2.7-2.8 μm . (c) Raman soliton jenerasyon nan yon solid-nwayo fliyò fib {{9}
