ʻO ka ʻāpana laser ultrafast kū hoʻokahi

Kūʻokoʻalaser wikiwiki loahapa hookahi

Nā waiwai kū hoʻokahi o ka ultrafastnā lasers
ʻO ka lōʻihi o ka pulse pōkole o nā lasers ultrafast e hāʻawi i kēia mau ʻōnaehana i nā waiwai kūʻokoʻa e hoʻokaʻawale iā lākou mai nā lasers lōʻihi-pulse a i ʻole ka hawewe mau (CW). No ka hana ʻana i kēlā pulse pōkole, koi ʻia kahi bandwidth ākea ākea. ʻO ke ʻano o ka pulse a me ka lōʻihi o ka nalu waena e hoʻoholo i ka bandwidth liʻiliʻi e pono ai e hana i nā pulses o kahi lōʻihi. ʻO ka mea maʻamau, ua wehewehe ʻia kēia pilina ma ke ʻano o ka huahana time-bandwidth (TBP), i loaʻa mai ke kumu ʻike maopopo ʻole. Hāʻawi ʻia ka TBP o ka pulse Gaussian e kēia ʻano: TBPGaussian=ΔτΔν≈0.441
ʻO Δτ ka lōʻihi o ka pulse a ʻo Δv ka bandwidth alapine. ʻO ke kumu, hōʻike ka hoʻohālikelike aia kahi pilina inverse ma waena o ka bandwidth spectrum a me ka lōʻihi o ka pulse, ʻo ia hoʻi i ka emi ʻana o ka manawa o ka pulse, e koi ʻia ka bandwidth e hoʻonui i kēlā pulse. Hōʻike ka Figure 1 i ka bandwidth liʻiliʻi e pono ai ke kākoʻo i nā lōʻihi pulse like ʻole.

Kiʻi 1: Pono ka bandwidth spectral liʻiliʻi e kākoʻonā puʻupuʻu lasero 10 ps ('ōmaʻomaʻo), 500 fs (uliuli), a me 50 fs (ʻulaʻula)

ʻO nā pilikia ʻenehana o nā laser ultrafast
Pono e mālama pono ʻia ka bandwidth spectral ākea, ka mana kiʻekiʻe, a me ka lōʻihi o ka pulse o nā laser ultrafast i kāu ʻōnaehana. ʻO ka pinepine, ʻo kekahi o nā hoʻonā maʻalahi i kēia mau pilikia ʻo ia ka puka ākea ākea o nā lasers. Inā ua hoʻohana mua ʻoe i ka pulse lōʻihi a i ʻole nā ​​laser hawewe mau i ka wā ma mua, ʻaʻole hiki i kāu waihona o nā ʻāpana optical ke noʻonoʻo a hoʻouna i ka bandwidth piha o nā pulse ultrafast.

ʻO ka paepae pōʻino laser
He ʻokoʻa loa a ʻoi aku ka paʻakikī o ka hoʻokele ʻana i nā paepae hōʻino laser (LDT) i hoʻohālikelike ʻia me nā kumu laser maʻamau. Ke hāʻawi ʻia nā optics nonā laser pulsed nanosecond, Loaʻa nā waiwai LDT ma ke kaʻina o 5-10 J/cm2. No ka ultrafast optics, ʻaʻole i lohe ʻia nā waiwai o kēia nui, no ka mea, ʻoi aku ka nui o nā waiwai LDT ma ke kauoha o <1 J/cm2, kokoke i ka 0.3 J/cm2. ʻO ka hoʻololi koʻikoʻi o ka amplitude LDT ma lalo o nā lōʻihi pulse like ʻole ka hopena o ka mīkini hōʻino laser e pili ana i ka lōʻihi o ka pulse. No nā laser nanosecond a i ʻole ka lōʻihinā laser pulsed, ʻo ka hana nui e hoʻopōʻino ai ʻo ia ka hoʻomehana wela. ʻO ka uhi a me nā mea substrate o kanā mea ʻike makae hoʻopaʻa i nā kiʻi i hana ʻia a hoʻomehana iā lākou. Hiki i kēia ke alakaʻi i ka distortion o ka lattice crystal o ka mea. ʻO ka hoʻonui wela, ka pohā, ka heheʻe a me ke kānana lattice ka hana maʻamau o ka pōʻino wela o kēia mau meapuna laser.

Eia nō naʻe, no nā laser ultrafast, ʻoi aku ka wikiwiki o ka pulse ma mua o ka manawa o ka hoʻoili ʻana o ka wela mai ka laser i ka lattice material, no laila ʻaʻole ka hopena wela ke kumu nui o ka pōʻino i hoʻoiho ʻia e ka laser. Akā, ʻo ka mana kiʻekiʻe o ka laser ultrafast e hoʻololi i ka mīkini pōʻino i nā kaʻina nonlinear e like me ka multi-photon absorption a me ka ionization. ʻO kēia ke kumu e hiki ʻole ai ke hōʻemi wale i ka helu LDT o kahi pulse nanosecond i kēlā o kahi pulse ultrafast, no ka mea, ʻokoʻa ke ʻano kino o ka pōʻino. No laila, ma lalo o nā kūlana like o ka hoʻohana ʻana (e laʻa, ka lōʻihi o ka nalu, ka lōʻihi o ka pulse, a me ka helu hou ʻana), ʻo kahi hāmeʻa optical me ka LDT kiʻekiʻe kiʻekiʻe e lilo i mea ʻike maikaʻi loa no kāu noi kikoʻī. ʻAʻole hōʻike ʻia nā Optics ma lalo o nā kūlana like ʻole i ka hana maoli o nā optics like i ka ʻōnaehana.

Kiʻi 1: Nā ʻano hana o ka ʻino i hoʻokomo ʻia i ka laser me nā lōʻihi pulse like ʻole