Application of the active harmonically mode-locked laser to rubidium atomic spectroscopy

• Main Authors: Po-Chun Huang, 黃柏鈞
• Other Authors: Che-Chung Chou
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/88945318380988409482

碩士 === 逢甲大學 === 光電研究所 === 95 === In this thesis, an active mode-locked fiber laser system was built up with a semi-conductor optical amplifier (SOA) instead of an Erbium doped fiber amplifier. The SOA was used to be a gain medium and to generate second harmonic signal to probe the spectrum of rubidium atom. The mode-locked laser source with more than 60 dB of the supermode noise suppression ratio and 0.4 nm of the optical spectrum width was demonstrated successfully. In the second part of this thesis, the second harmonic signals of a distributed feedback laser diode (DFB LD) was generated with SOA and used to probe the D2 lines of rubidium atom. With the frequency modulation technique, we got the derivative signal of D2 line. By this way, we successfully stabilize the 1.56-μm DFB LD, and the stability was estimated about 1.57×10-9. In the last part of this thesis, we tried to use the active harmonic mode-locked laser to observe the coherent population trapping (CPT). The results of the experimentations show that the parameters setting to optimize the active harmonic mode-locked laser and the absorption of the D2 lines of rubidium atom are different. The absorption of D2 lines of rubidium atom was almost vanish when the DFB LD modulated with radio frequency (RF) sinusoidal signal. Thus we couldn’t distinguish signals between absorption and non-absorption. The details will be present in the thesis.