ʻO ka nānā ʻana o nā laser pulsed

Nānā nui onā laser pulsed

ʻO ke ala pololei loa e hana ailaserʻO nā pulses e hoʻohui i kahi modulator i waho o ka laser mau. Hiki i kēia ala ke hana i ka pulse picosecond wikiwiki loa, ʻoiai maʻalahi, akā ʻaʻole hiki ke hoʻopau i ka ikehu māmā a me ka mana kiʻekiʻe ma mua o ka mana māmā mau. No laila, ʻo kahi ala ʻoi aku ka maikaʻi o ka hoʻoulu ʻana i nā pulse laser ʻo ia ka hoʻololi ʻana i ka lua laser, mālama i ka ikehu i ka manawa o ke kaʻa pulse a hoʻokuʻu iā ia i ka manawa. ʻO nā ʻenehana maʻamau ʻehā i hoʻohana ʻia no ka hoʻoulu ʻana i nā pulses ma o ka modulation cavity laser ʻo ka hoʻololi ʻana, Q-switching (loss switching), cavity emptying, a me ka mode-locking.

Hoʻopuka ka mea hoʻololi i nā pulu pōkole ma ka hoʻololi ʻana i ka mana o ka paila. No ka laʻana, hiki i ka semiconductor gain-switched lasers ke hoʻoulu i nā pulses mai kahi mau nanoseconds i hoʻokahi haneli picoseconds e ka modulation o kēia manawa. ʻOiai he haʻahaʻa ka ikaika o ka pulse, hiki ke maʻalahi kēia ʻano, e like me ka hāʻawi ʻana i ke alapine hoʻololi hiki ke hoʻololi ʻia a me ka laulā pulse. Ma 2018, ua hōʻike nā mea noiʻi ma ke Kulanui o Tokyo i kahi femtosecond gain-switched semiconductor laser, e hōʻike ana i kahi holomua i loko o kahi bottleneck ʻenehana 40 mau makahiki.

Hoʻokumu pinepine ʻia nā pulse nanosecond ikaika e nā lasers Q-switched, i hoʻokuʻu ʻia i loko o kekahi mau huakaʻi pōʻai i loko o ka lua, a ʻo ka ikehu pulse ma ka laulā o nā millijoules a i kekahi mau joules, ma muli o ka nui o ka ʻōnaehana. ʻO ka ikehu maʻamau (maʻamau ma lalo o 1 μJ) picosecond a me femtosecond pulses e hana nui ʻia e nā lasers paʻa ʻia. Aia hoʻokahi a ʻoi aku paha nā puʻupuʻu ultrashort i loko o ka resonator laser e holo mau ana. Hoʻouna kēlā me kēia pulse intracavity i kahi pulse ma o ke aniani hoʻopili hoʻopuka, a ʻo ka requency ma waena o 10 MHz a me 100 GHz. Hōʻike ka kiʻi ma lalo i kahi dispersion maʻamau piha (ANDi) dissipative soliton femtosecondmea laser fiber, hiki ke kūkulu ʻia ka hapa nui o ia mau mea me ka hoʻohana ʻana i nā mea maʻamau Thorlabs (fiber, lens, mount and displacement table).

Hiki ke hoʻohana ʻia ka ʻenehana hoʻokaʻawale ʻana noNā lasers hoʻololi Qe kiʻi i nā pulses pōkole a me nā lasers paʻa i ke ʻano e hoʻonui ai i ka ikehu pulse me ka requency haʻahaʻa.

ʻO ka pūnaewele manawa a me nā pulse domain frequency
ʻO ke ʻano laina o ka pulse me ka manawa maʻalahi a hiki ke hōʻike ʻia e nā hana Gaussian a me sech². Hōʻike pinepine ʻia ka manawa Pulse (ʻike pū ʻia ʻo ka laulā pulse) e ka hapalua kiʻekiʻe ka laulā (FWHM), ʻo ia hoʻi, ʻo ka laulā ma kahi o ka mana optical he hapa liʻiliʻi o ka mana kiʻekiʻe; Hoʻopuka ka laser Q-switched i nā pulse pōkole nanosecond ma o
Hoʻopuka nā lasers i hoʻopaʻa ʻia i ke ʻano i nā pulses ultra-short (USP) ma ke ʻano o nā ʻumi picoseconds a i femtoseconds. Hiki ke ana ʻia nā mea uila uila kiʻekiʻe a hiki i nā ʻumi picoseconds, a hiki ke ana ʻia nā pulse pōkole me nā ʻenehana optical maʻemaʻe e like me autocorrelators, FROG a me SPIDER. ʻOiai ʻaʻole hiki ke hoʻololi i ka laulā o ka pulse nanosecond a i ʻole ka lōʻihi i ko lākou hele ʻana, ʻoiai ma kahi lōʻihi, hiki ke hoʻopili ʻia nā pulse ultra-pōkole e nā kumu like ʻole:

Hiki ke hoʻopuehu ʻia i ka hoʻonui ʻia ʻana o ka pulse, akā hiki ke hoʻopili hou ʻia me ka hoʻopuehu ʻē aʻe. Hōʻike kēia kiʻi i ke ʻano o ka Thorlabs femtosecond pulse compressor i uku no ka hoʻopuehu microscope.

ʻAʻole pili pono ka nonlinearity i ka laula pulse, akā hoʻonui ia i ka bandwidth, e hoʻomāhuahua ai i ka pulse i ka wā e hoʻolaha ai. ʻO kēlā me kēia ʻano o ka fiber, me nā media loaʻa ʻē aʻe me ka bandwidth liʻiliʻi, hiki ke hoʻopili i ke ʻano o ka bandwidth a i ʻole ka pulse ultra-short, a ʻo ka emi ʻana o ka bandwidth hiki ke alakaʻi i kahi ākea i ka manawa; Aia kekahi mau hihia kahi e pōkole ai ka laulā pulse o ka puʻupuʻu ikaika i ka wā e liʻiliʻi ai ka spectrum.