Optomehanika hladnih atoma uzrokovana femtosekundnim laserskim zračenjem

master's thesis

• Title (english): Femtosecond laser optomechanics in cold atoms
• Author: Danijel Buhin
• Mentor: Ticijana Ban (mentor)
• Mentor: Damir Veža (mentor)
• Committee member: Damir Veža (predsjednik povjerenstva)
• Committee member: Ticijana Ban (član povjerenstva)
• Committee member: Davor Horvatić (član povjerenstva)
• Committee member: Matko Milin (član povjerenstva)
• Committee member: Marinko Jablan (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2017-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

U ovom radu proučavala se sila zračenja niza femtosekundnih pulseva na oblak hladnih atoma rubidija. Atomi rubidija hladili su se pomoću magneto-optičke stupice. Osim mjerenja ispitana je teorijska pozadina sile zračenja na atome koju stvara jedan niz femtosekundnih pulseva te dva niza suprotnopropagirajuća niza femtosekudnih pulseva. U slučaju s dva niza femtosekundnih pulseva promatrane su dva slučaja faznog odnosa izmedu pulseva, slučaj kada su pulsevi u fazi i kada su pulsevi u protufazi. Mjerenja sile zračenja provedena su za jednu granu femtosekundnih pulseva te za dvije grane femtosekundnih pulseva koji se propariraju u suprotnim smjerovima. Sila zračenja jedne grane pulseva slaže se s teorijskim modelom. U slučaju mjerenja s dvije grane, mjerili smo u dvije konfiguracije, u konfiguraciji ”u fazi” i ”u protufazi”. Za konfiguraciju ”u protufazi” očekujemo da na atom ne djeluje sila zračenja. Mjerenjima smo pokazali kako u slučaju ”u fazi” pomak centra mase oblaka hladnih atoma posljedina je geometrije laserskih zrake te nejednakih intenziteta. Osim što smo proučavali silu izmjerili smo spektralne širine lasera koje koristimo u eksperimentu.

Abstract (english)

In this thesis, we studied radiation force of a femtosecond pulse train on cold rubidium atoms. Cooling of rubidium atoms is established by magneto-optic trap. We also studied theory of radiation force on atoms made by one femtosecond pulse train and two counter-propagating pulse trains. In case of two counter-propagating pulse trains we studied two cases of phase differences between pulses, case when pulses are in phase and when they are out of phase. Radiation force is measured for one femtosecond pulse train and for two counter-propagating pulse trains. In case of one pulse train measured radiation force matches theoretical model. In case of two pulse trains we made measurement in two configurations: ”in phase” and ”out of phase”. For ”out of phase” configuration, it is expected that there is no radiation force on atoms. For ”in phase” configuration, displacement of the cold atoms cloud center of mass is effect of femtosecond beams imbalance. We also measured spectral width of lasers that are used in experiment.

• Keywords: magneto-optička stupica; femtosekundni laser; sila zračenja; atom rubidija; spektralna širina
• Keywords (english): magneto-optic trap; femtosecond laser; radiation force; rubudium atom; spectral width.
• Language: croatian
• URN:NBN: urn:nbn:hr:217:110760
• Study programme: Title: Physics; specializations in: Research; Course: Research; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-07-27 10:44:10