Department of Physics
Student Seminar Announcement for Wednesday, April 10
Apr 8, 2013
PHYS600 Wednesday, April 10, 4:00-4:50 pm
Currens Hall 205
All physics faculty and students are invited.
Speaker: Yogeshbhai Patel
Graduate Student, Physics Department, WIU
Title: "Laser Cooling"
Laser cooling is cooling of atomic or molecular species to near absolute zero temperatures by the interaction with one or more laser beams. It is used to observe unique quantum effects which can occur only near absolute zero temperature. There are various methods for laser cooling. In Doppler cooling method temperature of the order of microkelvin is achieved. In this method a laser is tuned slightly below the center frequency of a strong allowed transition in the atom or ion to be cooled. The radiation is therefore Doppler-shifted into resonance with the transition frequency when the atom is moving towards the laser beam. This leads to the reduction of momentum of atoms. The net effect is that the atom is slowed down (cooled). In the method of Magneto-Optical trapping, with the addition of a magnetic field gradient, the velocity reduction of Doppler cooling can be used to help confine and trap neutral atoms. Combining magnetic trap, laser cooling, evaporative cooling and ultra-high vacuum we can produce Bose-Einstein condensates. In this presentation I will explain these phenomena with an introduction to lasers.