Bayani game da lasers masu bugun jini

Bayani game dana'urorin laser masu bugun jini

Hanya mafi kai tsaye don samar dalaserPuls shine ƙara modulator zuwa wajen laser mai ci gaba. Wannan hanyar na iya samar da bugun picosecond mafi sauri, kodayake yana da sauƙi, amma kuzarin haske da ƙarfin kololuwa ba za su iya wuce ƙarfin haske mai ci gaba ba. Saboda haka, hanya mafi inganci don samar da bugun laser shine a daidaita a cikin ramin laser, adana makamashi a lokacin da ba a gama ba na jirgin bugun jini sannan a sake shi a kan lokaci. Dabaru guda huɗu da aka saba amfani da su don samar da bugun jini ta hanyar daidaita ramin laser sune canjin riba, sauya Q (canzawa asara), fitar da rami, da kuma kulle yanayin.

Maɓallin samun riba yana samar da gajerun bugun jini ta hanyar daidaita ƙarfin famfo. Misali, lasers masu canza gain-switched na semiconductor na iya samar da bugun jini daga 'yan nanoseconds zuwa 100 picoseconds ta hanyar daidaitawar yanzu. Duk da cewa ƙarfin bugun jini yana da ƙasa, wannan hanyar tana da sassauƙa sosai, kamar samar da mitar maimaitawa mai daidaitawa da faɗin bugun jini. A cikin 2018, masu bincike a Jami'ar Tokyo sun ba da rahoton laser semiconductor mai canza gain-switched femtosecond, wanda ke wakiltar ci gaba a cikin matsala ta fasaha ta shekaru 40.

Galibi ana samar da ƙarfin bugun nanosecond ta hanyar amfani da na'urorin laser masu canzawa na Q, waɗanda ake fitarwa a cikin tafiye-tafiye da yawa a cikin ramin, kuma kuzarin bugun yana cikin kewayon millijoules da yawa zuwa joules da yawa, ya danganta da girman tsarin. Matsakaicin kuzari (galibi ƙasa da 1 μJ) picosecond da femtosecond bugun ana samar da su ne ta hanyar lasers masu kulle yanayin. Akwai bugun bugun guda ɗaya ko fiye a cikin resonator na laser wanda ke zagayawa akai-akai. Kowane bugun bugun cikin rami yana watsa bugun jini ta madubin haɗin fitarwa, kuma sake zagayowar yawanci yana tsakanin 10 MHz da 100 GHz. Hoton da ke ƙasa yana nuna cikakken watsawa na al'ada (ANDi) dissipative soliton femtosecondna'urar laser fiber, yawancinsu ana iya gina su ta amfani da kayan aikin Thorlabs na yau da kullun (zare, ruwan tabarau, wurin hawa da teburin motsi).

Ana iya amfani da hanyar zubar da ramuka donLasers masu canzawa na Qdon samun gajerun bugun jini da lasers masu kullewa don ƙara ƙarfin bugun jini tare da ƙarancin sake maimaitawa.

Rarraba yankin lokaci da mita na yankin
Siffar layi ta bugun jini tare da lokaci gabaɗaya abu ne mai sauƙi kuma ana iya bayyana shi ta hanyar ayyukan Gaussian da sech². Lokacin bugun jini (wanda kuma aka sani da faɗin bugun jini) galibi ana bayyana shi ta hanyar ƙimar rabin tsayi (FWHM), wato, faɗin da ƙarfin gani yake a kai aƙalla rabin ƙarfin kololuwa; Laser mai canzawa na Q yana samar da gajerun bugun nanosecond ta hanyar
Na'urorin laser masu kulle yanayin suna samar da bugun ultra-short (USP) a cikin jerin goma na picoseconds zuwa femtoseconds. Na'urorin lantarki masu sauri za su iya auna har zuwa goma na picoseconds kawai, kuma gajerun bugun ana iya auna su ne kawai ta amfani da fasahar gani kamar autocorrelators, FROG da SPIDER. Duk da cewa nanosecond ko dogayen bugun ba sa canza faɗin bugun su yayin da suke tafiya, ko da a cikin nisa mai nisa, bugun ultra-short na iya shafar abubuwa da yawa:

Watsawa na iya haifar da faɗaɗa bugun jini mai yawa, amma ana iya sake matse shi da rarrabawa akasin haka. Zane mai zuwa yana nuna yadda na'urar compressor ta Thorlabs femtosecond ke ramawa ga watsawar microscope.

Rashin daidaituwa gabaɗaya ba ya shafar faɗin bugun jini kai tsaye, amma yana faɗaɗa bandwidth, yana sa bugun jini ya fi saurin wargajewa yayin yaɗuwa. Duk wani nau'in zare, gami da wasu kafofin watsa labarai masu ƙarancin bandwidth, na iya shafar siffar bandwidth ko bugun jini mai gajere, kuma raguwar bandwidth na iya haifar da faɗaɗawa cikin lokaci; Akwai kuma lokuta inda faɗin bugun jini na bugun jini mai ƙarfi ya zama gajarta lokacin da bakan ya zama kunkuntar.