Depletion, quantum jumps, and temperature measurements of ⁸⁸Sr⁺ ions in a linear Paul Trap

Abstract

This thesis describes the design and construction of two laser systems to probe the 674nm transition of ⁸⁸Sr⁺ ions in a linear Paul trap. The first laser system made use of a molecular transition in Iodine to stabilize the length of a Fabry-Perot cavity for laser locking. After constructing this laser, we measured an unsuitable experimental stability of 10 MHz over 5 minutes. A completely new monolithic laser system was built, providing better environmental isolation and a frequency stability of at least 1 MHz over 5 minutes. Using this laser, we were able to observe depletion and quantum jump effects in our ion trap system. Additionally, by scanning the red laser frequency, we were able to see the blue-laser broadened spectrum of the 674nm transition. Fitting the spectrum to a Voigt function yielded an ion temperature of 35 mK. To avoid blue-broadening, we set up blue and red laser pulse sequences. This allowed us to observe a red spectrum with secular sidebands and calculate an ion temperature of 6.8 +4.4 / -2.2 mK.