Hoʻolauna
ʻO ke kukui Mid-infrared (MIR) ma ka laulā o 2-20 µm he mea pono no ka ʻike kemika a me ke olaola ma muli o ka nui o nā laina absorption molecular hiʻohiʻona i kēia māhele spectral.Hiki ke hoʻohana hou ʻia nā noi hou e like me mirco-spectroscopy, femtosecond pump-probe spectroscopy, a me nā ana hoʻonaninani kiʻekiʻe a hiki i kēia manawa ua nui nā papahana.
ua hoʻomohala ʻia e hoʻohua i ka pāhawewe MIR pili, e like me nā laina synchrotron beam, quantum cascade lasers, supercontinuum kumu, optical parametric oscillators (OPO) a me nā optical parametric amplifier (OPA).Loaʻa i kēia mau papahana ko lākou mau ikaika a me nā nāwaliwali e pili ana i ka paʻakikī, ka bandwidth, ka mana, ka pono, a me ka lōʻihi o ka pulse.Ma waena o lākou, ʻo ka intra-pulse difference frequency generation (IDFG) ke ʻimi nei i ka ulu ʻana o ka manaʻo e hoʻomaikaʻi i ka hoʻomohala ʻana o nā lasers femtosecond 2 µm kiʻekiʻe e hiki ke hoʻomake pono i nā kristal non-oxide nonlinear liʻiliʻi-bandgap e hoʻohua i ke kukui MIR koʻikoʻi.Hoʻohālikelike ʻia i nā OPO a me nā OPA maʻamau, ʻae ʻo IDFG i ka hōʻemi ʻana i ka paʻakikī o ka ʻōnaehana a me ka hoʻonui ʻana i ka hilinaʻi, no ka mea, ua wehe ʻia ka pono e hoʻohālikelike i ʻelua mau kaola kaʻawale a i ʻole nā lua i ka pololei kiʻekiʻe.Ma waho aʻe o kēia, ʻo ka hoʻopuka MIR he mea paʻa paʻa ʻo carrier-envelope-phase (CEP) me IDFG.
Fig 1
ʻO ke kiko hoʻouna o ka 1-mm-mānoanoa i uhi ʻole ʻiaBGSe anianihāʻawi ʻia e DIEN TECH.Hōʻike ka inset i ke aniani maoli i hoʻohana ʻia i kēia hoʻokolohua.
Fig 2
Hoʻonohonoho hoʻokolohua o ka hanauna MIR me aBGSe aniani.OAP, ke aniani parabolic off-axis me ka lōʻihi o ka nānā pono ʻana o 20 mm;HWP, pā hawewe hawewe;TFP, polarizer kiʻiʻoniʻoni lahilahi;LPF, kānana holo lōʻihi.
I ka makahiki 2010, ua hana ʻia kahi kristal biaxial chalcogenide nonlinear hou, BaGa4Se7 (BGSe), me ka hoʻohana ʻana i ke ʻano Bridgman-Stockbarger.Loaʻa iā ia kahi ākea ākea mai ka 0.47 a hiki i ka 18 µm (e like me ka hōʻike ʻana ma ka Fig. 1) me nā coefficient nonlinear o d11 = 24.3 pm/V a me d13 = 20.4 pm/V.ʻOi aku ka laulā o ka puka aniani o BGSe ma mua o ZGP a me LGS ʻoiai ʻoi aku ka haʻahaʻa o kona nonlinearity ma mua o ZGP (75 ± 8 pm/V).ʻOkoʻa me GaSe, hiki ke ʻoki ʻia ʻo BGSe ma ke kihi hoʻohālikelike i makemake ʻia a hiki ke uhi ʻia i ka anti-reflection.
Hōʻike ʻia ka hoʻonohonoho hoʻokolohua ma Fig. 2(a).Hoʻokumu mua ʻia nā pulse hoʻokele mai kahi ʻano oscillator ʻo Kerr-lens i kūkulu ʻia i ka home me ka polycrystalline Cr: ZnS crystal (5 × 2 × 9 mm3, hoʻouna ʻia=15% ma 1908nm) ʻoiai ʻo ka loaʻa ʻana o ka mīkini paʻi ʻia e kahi. Tm-doped fiber laser ma 1908nm.Hāʻawi ka oscillation i loko o kahi lua hawewe kū i nā pulses 45-fs e hana ana ma ka helu hou ʻana o 69 MHz me ka mana awelika o 1 W ma kahi lōʻihi hawewe o 2.4 µm.Hoʻonui ʻia ka mana i 3.3 W i kahi polycrystalline Cr: ZnS amplifier i kūkulu ʻia i ka home (5 × 2 × 6 mm3, hoʻoili = 20% ma 1908nm a me 5 × 2 × 9 mm3, hoʻouna = 15% ma 1908nm), a ua ana ʻia ka lōʻihi o ka pulse puka me kahi mea hana lua-harmonic-generation frequency-resolved optical grating (SHG-FROG) i kūkulu ʻia i ka home.
