Source: https://www.osapublishing.org/oe/abstract.cfm?uri=oe-16-5-2922
Timestamp: 2019-04-23 12:41:48+00:00

Document:
We demonstrate passive mode-locking by means of a semi-conductor saturable-absorber mirror in a diode-pumped Yb:YLF laser. We present crystal growth process, spectroscopic measurements, and investigation of mode-locking performance. Pulse trains with minimum duration of 196 fs, average power of 54 mW and a repetition rate of 55 MHz were obtained. The optical spectrum, centered at 1028 nm, has a 7.1-nm bandwidth leading to nearly transform-limited pulses.
F. Druon, S. Chénais, P. Raybaut, F. Balembois, P. Georges, R. Gaumé, G. Aka, B. Viana, S. Mohr, and D. Kopf, “Diode-pumped Yb:Sr3Y(BO3)3 femtosecond laser,” Opt. Lett. 27, 197–199 (2002).
F. Druon, F. Balembois, P. Georges, A. Brun, A. Courjaud, C. Hönninger, F. Salin, A. Aron, F. Mougel, G. Aka, and D. Vivien, “Generation of 90-fs pulses from a mode-locked diode-pumped Yb3+:Ca4GdO(BO3)3 laser,” Opt. Lett. 25, 423–425 (2000).
A. García-Cortés, J. M. Cano-Torres, M. D. Serrano, C. Cascales, C. Zaldo, S. Rivier, X. Mateos, U. Griebner, and V. Petrov, “Spectroscopy and Lasing of Yb-Doped NaY(WO4)2: Tunable and Femtosecond Mode-Locked Laser Operation,” IEEE J. Quantum Electron. 43, 758–764 (2007).
U. Griebner, S. Rivier, V. Petrov, M. Zorn, G. Erbert, M Weyers, X. Mateos, M. Aguiló, J. Massons, and F. Dĺaz, “Passively mode-locked Yb:KLu(WO4)2 oscillators,” Opt. Express 13, 3465–3470 (2005).
V. E. Kisel, N. A. Tolstik, A. E. Troshin, N. V. Kuleshov, V. N. Matrosov, T. A. Matrosova, M. I. Kupchenko, F. Brunner, R. Paschotta, F. Morier-Genoud, and U. Keller, “Spectroscopy and femtosecond laser performance of Yb3+:Gd0.64Y0.36VO4 crystal,” Appl. Phys. B 85, 581–584 (2006).
C. Hönninger, F. Morier-Genoud, M. Moser, U. Keller, L. R. Brovelli, and C. Harder, “Efficient and tunable diode-pumped femtosecond Yb:glass lasers,” Opt. Lett. 23, 126–128 (1998).
J. Murray, “Pulsed gain and thermal lensing of Nd:LiYF4,” IEEE J. Quantum Electron. 19, 488–491 (1983).
W. Koechner, Solid-state laser engineering, 4th ed. (Springer, Berlin, 1996), pp 60–63.
J. Kawanaka, H. Nishioka, N. Inoue, and K. Ueda, “Tunable continuous-wave Yb:YLF laser operation with a diode pumped chirped-pulse amplification system,” Appl. Opt. 40, 3542–3546 (2001).
M. Vannini, G. Toci, D. Alderighi, D. Parisi, F. Cornacchia, and M. Tonelli, “High efficiency room temperature laser emission in heavily doped Yb:YLF,” Opt. Express 15, 7994–8002 (2007).
A. Lucca, G. Debourg, M. Jacquemet, F. Druon, F. Balembois, P. Georges, P. Camy, J. L. Doualan, and R. Moncorgé, “High-power diode-pumped Yb3+:CaF2 femtosecond laser,” Opt. Lett. 29, 2767–2769 (2004).
V. Petrov, U. Griebner, D. Ehrt, and W. Seeber, “Femtosecond self mode locking of Yb:fluoride phosphate glass laser,” Opt. Lett. 22, 408–410 (1997).
A. Bensalah, Y. Guyot, M. Ito, A. Brenier, H. Sato, T. Fukuda, and G. Boulon, “Growth of Yb3+-doped YLiF4 laser crystal by the Czochralski method. Attempt of Yb3+ energy level assignment and estimation of the laser potentiality,” Opt. Mater. 26, 375–383 (2004).
B. Aull and H. P. Jenssen, “Vibronic Interactions in Nd:YAG Resulting in Nonreciprocity of Absorption and Stimulated Emission Cross Sections,” IEEE J. Quantum Electron. 18, 925–930 (1982).
L. D. DeLoach, S. A. Payne, L. L. Chase, L. K. Smith, W. L. Kway, and W. F. Krupke, “Evaluation of absorption and emission properties of Yb3+ doped crystals for laser applications,” IEEE J. Quantum Electron. 29, 1179–1191 (1993).
Fig. 1. Room-temperature absorption and emission cross sections of Yb3+ ions in YLF crystal with electric field polarizations (a) E‖c, and (b) E⊥c. Emission cross sections were evaluated with the reciprocity method for wavelengths shorter than 1020 nm and with the β-τ method for wavelengths longer than 1020 nm.
Fig. 2. Gain cross-sections of Yb3+ ions in YLF crystal for inversion parameter β of 0.1, 0.15, 0.2, and 0.25, with electric field polarizations (a) E‖c, and (b) E⊥c.
Fig. 3. Scheme of the mode-locked Yb:YLF laser cavity and pump system. LD1, LD2: laser diodes; F1, F2, F3, F4: lenses; M1, M2: folding mirrors; M3, focusing mirror; M4, M5: chirped mirrors; C: Yb-doped YLF crystal; OC: output coupler; SESAM: semiconductor saturable-absorber mirror.
Fig. 4. Average output power versus incident pump power of the mode-locked Yb:YLF laser with polarization E‖c, and output couplings of 1% (squares), and 2% (circles). Mode-locking thresholds are indicated by arrows.
Fig. 5. Autocorrelation trace and optical spectrum (inset) of the mode-locked Yb:YLF laser with polarization E‖c: (a) 1% output coupler ; (b) 2% output coupler. Sech2- pulse shape is assumed.

References: V. 
 V. 

V. 
 V. 
 V. 

V.