Taw qhia
Mid-infrared (MIR) lub teeb nyob rau hauv thaj tsam ntawm 2-20 µm yog qhov muaj txiaj ntsig zoo rau kev txheeb xyuas tshuaj lom neeg thiab tshuaj lom neeg vim tias muaj ntau cov kab mob molecular haum rau hauv cheeb tsam spectral no.Ib qho kev sib koom ua ke, ob peb lub voj voog uas muaj kev sib koom ua ke ntawm qhov dav MIR ntau tuaj yeem ua rau cov ntawv thov tshiab xws li mirco-spectroscopy, femtosecond twj-survey spectroscopy, thiab high-dynamic-range rhiab ntsuas txog tam sim no ntau lub tswv yim muaj.
tau tsim los tsim kom muaj hluav taws xob sib txuas MIR, xws li cov kab hluav taws xob synchrotron, quantum cascade lasers, supercontinuum sources, optical parametric oscillators (OPO) thiab optical parametric amplifiers (OPA).Cov tswv yim no txhua tus muaj lawv tus kheej lub zog thiab qhov tsis muaj zog nyob rau hauv cov nqe lus ntawm complexity, bandwidth, lub zog, efficiency, thiab mem tes ntev.Ntawm lawv, intra-pulse sib txawv zaus tiam (IDFG) yog attracting kev mloog zoo ua tsaug rau txoj kev loj hlob ntawm high-power femtosecond 2 µm lasers uas muaj peev xwm ua tau zoo twj tso kua mis me me-bandgap non-oxide nonlinear crystals los tsim high-power broadband coherent MIR teeb.Piv nrog rau OPOs thiab OPAs siv ib txwm siv, IDFG tso cai rau txo qis hauv qhov system complexity thiab txhim khu kev ntseeg tau, raws li qhov yuav tsum tau ua kom haum ob kab sib cais los yog kab noj hniav ntawm high precision raug tshem tawm.Dhau li ntawd, MIR tso zis yog intrinsically carrier-pob ntawv-theem (CEP) ruaj khov nrog IDFG .
Fig 1
Transmission spectrum ntawm 1-mm-tuab uncoatedBGSe siv lead uamuab los ntawm DIEN TECH.Lub inset qhia qhov tseeb siv lead ua siv hauv qhov kev sim no.
Fig 2
Kev sim teeb tsa ntawm MIR tiam nrog aBGSe siv lead ua.OAP, off-axis parabolic daim iav nrog qhov ua kom pom tseeb ntev ntawm 20 hli;HWP, ib nrab-yoj phaj;TFP, nyias zaj duab xis polarizer;LPF, ntev-pass lim.
Nyob rau hauv 2010, ib tug tshiab biaxial chalcogenide nonlinear siv lead ua, BaGa4Se7 (BGSe), tau fabricated siv txoj kev Bridgman-Stockbarger .Nws muaj qhov pom dav dav ntawm 0.47 txog 18 µm (raws li qhia hauv daim duab 1) nrog nonlinear coefficients ntawm d11 = 24.3 pm / V thiab d13 = 20.4 pm / V.Lub qhov rais pob tshab ntawm BGSe yog qhov dav dua li ZGP thiab LGS txawm hais tias nws qhov tsis sib xws yog qis dua ZGP (75 ± 8 teev tsaus ntuj / V).Hauv kev sib piv rau GaSe, BGSe kuj tseem tuaj yeem raug txiav ntawm qhov xav tau theem-kev sib piv lub kaum sab xis thiab tuaj yeem tiv thaiv kev cuam tshuam.
Qhov kev sim teeb tsa tau piav qhia hauv daim duab 2(a).Cov tsav tsheb pulses yog pib tsim los ntawm lub tsev-tsim Kerr-lens hom-xauv Cr: ZnS oscillator nrog polycrystalline Cr: ZnS siv lead ua (5 × 2 × 9 mm3, kis = 15% ntawm 1908nm) raws li qhov nce nruab nrab pumped los ntawm a Tm-doped fiber ntau laser ntawm 1908nm.Lub oscillation nyob rau hauv ib tug sawv-yoj kab noj hniav muab 45-fs pulses ua hauj lwm ntawm ib tug repetition tus nqi ntawm 69 MHz nrog ib tug nruab nrab hwj chim ntawm 1 W ntawm ib tug cab kuj wavelength ntawm 2.4 µm.Lub zog yog amplified rau 3.3 W nyob rau hauv ib lub tsev-tsim ob-theem ib leeg-pass polycrystalline Cr: ZnS amplifier (5 × 2 × 6 mm3, kis = 20% ntawm 1908nm thiab 5 × 2 × 9 mm3, kis = 15% ntawm 1908nm), thiab lub sijhawm tso zis mem tes yog ntsuas nrog lub tsev-tsim thib ob-harmonic-tiam zaus-kho qhov muag grating (SHG-FROG) apparatus.
