Observation of spectral modulation coupled with broadband transverse-mode-locking in an Yb∶CALGO frequency-degenerate cavity

• 来源期刊: 中国光学快报（英文版）
• 年，卷（期）: 2019,（3）
• 页码范围: 60-65
• 页数: 6页
• 语种: 英文
• DOI: 10.3788/COL201917.031404

摘要

A frequency-degenerate cavity (FDC) is the resonator that the ratio of transverse and longitudinal mode frequency spacings is a simple rational number.When an optical resonator is close to the FDC,transverse-mode-locking (TML) takes place with drastic changes of laser mode.We report for the first time,to the best of our knowledge,the multi-frequency emission and spectral modulation effects coupled with TML iu FDC.The Yb∶CaGdAlO4 (Yb∶CALGO) crystal with large gain bandwidth was used as a gain medium iu an off-axis-pumped hemispherical FDC for realizing broadband emission.Interestingly,the spectrum can transform from a single smooth packet shape to a multi-peak structure;meanwhile,the transverse pattern accordingly transforms into some exotic wave-packet profiles through controlling off-axis displacement in a special degenerate state.