Continuous- wave Tm: YLF laser with ultrabroad tuning (1772-2145 nm)


Demirbas U., Thesinga J., BEYATLI E., Kellert M., Pergament M., Kaertner F. X.

OPTICS EXPRESS, sa.23, ss.41219-41239, 2022 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1364/oe.471288
  • Dergi Adı: OPTICS EXPRESS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, EMBASE, MEDLINE, Directory of Open Access Journals
  • Sayfa Sayıları: ss.41219-41239
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

We report detailed experimental data aiming for rigorous investigation of Tm:YLF laser performance, especially with a focus on tuning behavior. Continuous-wave (cw) lasing performance of Tm:YLF crystals with thulium dopings in the 2-6% range is investigated under diode and Ti:Sapphire pumping at 792 nm and 780 nm, respectively. While employing the c-axis, we have achieved cw lasing thresholds below 20mW, laser output power up to 1.42 W, and laser slope efficiencies as high as 70% with respect to absorbed pump power. The passive loss of the Tm:YLF crystal is estimated to be as low as 0.05% per cm, corresponding to a crystal figure of merit above 10000. Via employing this low-loss crystal and a 2-mm thick off-surface optical axis birefringent filter (BRF) with strong sideband rejection, a record cw tuning range covering the 1772-2145 nm interval is demonstrated (except a small gap between 1801-1815nm region). Detailed lifetime and emission cross section measurements have been performed to explain the observed performance, and strategies for further performance enhancement are discussed.