飛秒級被動鎖模鈦藍寶石雷射脈衝演變動力學之研究

Abstract

實驗上, 利用時間閘技術量測飛秒級被動鎖模鈦藍寶石雷射起動後在 同 瞬間的暫態自相關軌跡的對比率, 二倍頻轉換效率和百分能量來定量估計 鎖模程度. 我們觀察到雷射輸出由連續波到部分鎖模, 到完全鎖模的整個 演變過程. 此外, 染料濃度的高低並不會影響參與鎖模的起始振盪模數, 但改變腔內色散會影響參與鎖模的起始振盪模數, 實驗結果顯示: 共振腔 色散補償完全時, 參與鎖模的起始振盪模數最多. The evolution from cw to partial mode-locking, to completeode- locking in a femtosecond passively mode-locked:sapphire/DDI laser has been determined by measuring thetrast ratio of transient autocorrelation trace, the SHGersion efficiency, and the fractional energy at consecutivetime using the time-gating technique. Furthermore, it ismed that the concentration of the DDI absorber doesn'tce the number of the initially oscillating modes whichtes in mode-locking, but changing the dispersion of theld. Experimental results also show that for optimumcompensation, the number of the initially oscillatingparticipates in mode-locking may be maximum.