Kuwala kooneka kwa sub-20 femtosecondgwero la laser losinthika
Posachedwapa, gulu lofufuza kuchokera ku UK linafalitsa kafukufuku watsopano, wolengeza kuti apanga bwino kuwala kooneka ngati kamene kamasinthidwa kukhala ka megawatt-level sub-20 femtosecond.gwero la laser lozunguliraGwero la laser lothamanga ili, lothamanga kwambirilaser ya ulusiDongosololi limatha kupanga ma pulses okhala ndi ma wavelength osinthika, nthawi yochepa kwambiri, mphamvu zokwana ma nanojoules 39, komanso mphamvu yayikulu yoposa ma megawatts awiri, ndikutsegula mwayi watsopano wogwiritsa ntchito m'magawo monga ultrafast spectroscopy, biographical imaging, ndi mafakitale.
Chofunika kwambiri pa ukadaulo uwu chili mu kuphatikiza njira ziwiri zamakono: "Gain-Managed nonlinear Amplification (GMNA)" ndi "Resonant Dispersive Wave (RDW) emission". Kale, kuti mupeze ma pulse a ultrashshort osinthika kwambiri, ma laser a titanium-sapphire okwera mtengo komanso ovuta kapena ma amplifiers a optical parametric nthawi zambiri amafunika. Zipangizozi sizinali zodula zokha, zazikulu, komanso zovuta kuzisamalira, komanso zinali zochepa chifukwa cha kubwerezabwereza kochepa komanso kusintha kwa ma tuning ranges. Yankho la all-fiber lomwe linapangidwa nthawi ino silimangopangitsa kuti kapangidwe ka makina kakhale kosavuta komanso limachepetsa kwambiri ndalama ndi zovuta. Limathandizira kupanga mwachindunji ma sub-20 femtosecond, omwe amatha kusinthidwa kufika pa 400 mpaka 700 nanometers komanso kupitirira ma pulse amphamvu kwambiri pa frequency yobwerezabwereza ya 4.8 MHz. Gulu lofufuza lidapeza izi kudzera mu kapangidwe ka makina kokonzedwa bwino. Choyamba, adagwiritsa ntchito oscillator yosungira polarization-locked mode-locked ytterbium fiber oscillator yochokera pa nonlinear amplification ring mirror (NALM) ngati gwero la mbewu. Kapangidwe kameneka sikuti kamangotsimikizira kukhazikika kwa nthawi yayitali kwa dongosololi, komanso kumapewa vuto la kuwonongeka kwa ma absorption a thupi. Pambuyo pa preamplification ndi pulse compression, mbewu zimayikidwa mu gawo la GMNA. GMNA imagwiritsa ntchito self-phase modulation ndi longitudinal asymmetric gain distribution mu ulusi wa optical kuti ikwaniritse spectral broadening ndikupanga ultrashort pulses yokhala ndi linear chirp yangwiro, yomwe pamapeto pake imakakamizidwa ku sub-40 femtoseconds kudzera mu grating pairs. Pa gawo la RDW generation, ofufuza adagwiritsa ntchito ulusi wodzipangira wokha wa nine-resonator anti-resonance hollow-core. Mtundu uwu wa optical fiber uli ndi kutayika kochepa kwambiri mu pump pulse band ndi viewable light region, zomwe zimathandiza kuti mphamvu zisinthidwe bwino kuchokera ku pump kupita ku dispersed wave ndikupewa kusokonezedwa komwe kumachitika chifukwa cha high-loss resonant band. Pansi pa mikhalidwe yabwino kwambiri, mphamvu ya mafunde ofalikira omwe amatuluka ndi dongosololi imatha kufika ma nanojoules 39, m'lifupi mwa mafunde ofupi kwambiri amatha kufika ma femtoseconds 13, mphamvu yayikulu imatha kufika ma megawatts 2.2, ndipo mphamvu yosinthira mphamvu imatha kufika pa 13%. Chosangalatsa kwambiri ndichakuti posintha kuthamanga kwa mpweya ndi magawo a ulusi, dongosololi limatha kukulitsidwa mosavuta ku ma ultraviolet ndi ma infrared band, ndikukwaniritsa kusintha kwa wideband kuchokera ku ultraviolet yakuya kupita ku infrared.
Kafukufukuyu sali wofunika kwambiri pa nkhani yofunikira ya photonics, komanso akutsegula mkhalidwe watsopano m'magawo a mafakitale ndi ntchito. Mwachitsanzo, m'magawo monga kujambula kwa multi-photon microscopy, ultrafast time-resolved spectroscopy, kukonza zinthu, precision medicine, ndi kafukufuku wa ultrafast nonlinear optics, mtundu watsopano wa ultrafast light source watsopanowu, wogwira ntchito bwino, komanso wotsika mtengo udzapatsa ogwiritsa ntchito zida zosayerekezeka komanso kusinthasintha. Makamaka m'magawo omwe amafunikira kubwerezabwereza kwakukulu, mphamvu yayikulu komanso ma pulses afupiafupi, ukadaulo uwu mosakayikira ndi wopikisana kwambiri ndipo uli ndi kuthekera kwakukulu kokwezera poyerekeza ndi machitidwe achikhalidwe a titanium-saphire kapena optical parametric amplification.
Mtsogolomu, gulu lofufuza likukonzekera kukonza bwino dongosololi, monga kuphatikiza kapangidwe kamene kali ndi zigawo zingapo za kuwala kwa free-space kukhala ulusi wa kuwala, kapena kugwiritsa ntchito oscillator imodzi ya Mamyshev kuti ilowe m'malo mwa oscillator ndi amplifier, kuti akwaniritse kuchepetsedwa ndi kuphatikiza kwa dongosololi. Kuphatikiza apo, posintha mitundu yosiyanasiyana ya ulusi wotsutsana ndi resonance, kuyambitsa mpweya wa Raman active ndi ma module owirikiza kawiri, dongosololi likuyembekezeka kukulitsidwa kukhala gulu lalikulu, kupereka mayankho a laser opangidwa ndi ulusi wonse, wideband, ultrafast m'magawo angapo monga ultraviolet, kuwala kowoneka ndi infrared.
Chithunzi 1. Chithunzi chojambula cha kusintha kwa laser yoyendetsedwa ndi pulsed
Nthawi yotumizira: Meyi-28-2025