Z-scan Measurements of Optical Nonlinear Absorption and Refraction in Doppler-Broadened Rb Atoms

• Main Authors: Chih-chieh Lin, 林志杰
• Other Authors: Dian-jiun Han
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/10437492764878707661

碩士 === 國立中正大學 === 物理所 === 97 === We use z-scan technique to research optical nonlinear effect for Rb vapor and measure optical nonlinear absorption and refraction in Doppler-broaden Rb atoms (Doppler line-width is 332 MHz at 79℃). There are mixing lensing effect by isotopes of Rb atoms, Rubidium-87 and Rubidium-85.To observe optical lensing effect, we set up an optical system of changing detuning. Then we can observe lensing effect at different detuning. When lensing effect of Rubidium-87 and lensing effect of Rubidium-85 cancel out, we say zero lensing effect that we are interested in it. With z-scan program of thin cell, we fit experimental data to get parameters of incident beam and Rb atoms and calculate nonlinear refractive index of two isotopes. We research optical nonlinear effect of two isotopes, F=2→F’ of Rubidium-87 and F=3→F’ of Rubidium-85.Difference is 1.2 GHz for transition of two isotopes. Using program predicts detuning of zero lensing effect, and we can take data to test with optical system of changing detuning.