Diode-pumped mode-locked Yb³⁺:Lu₂O₃ceramic laser

Abstract

We report a diode-pumped passively mode-locked Yb(3+):Lu(2)O(3) ceramic laser by use of a semiconductor saturable absorber mirror. Almost transform-limited 357 fs pulses at the center wavelength of 1033.5 nm with a maximum average power of 352 mW are obtained. The efficiency against the absorbed pump power is as high as 32% by use of a laser-diode pumping and the repetition rate is 97 MHz. This is the first demonstration of a diode-pumped mode-locked Yb(3+):Lu(2)O(3) ceramic laser to our knowledge.

Laser Performance of 1% at. Yb : Lu2O3 Ceramic

“…Although the absorption cross sections at 968 nm is low, that is, σ abs (968 nm) = 0.27 × 10 −20 cm 2 , it is relatively insensitive to the variation of the pump wavelength, which is kept constant at the different pumping powers by changing the cooling temperature of the laserdiode. This arrangement reduces the requirement of a tight stabilization of the pump emission wavelength over a wide range of laser-diode input, as required by the narrow width of the absorption peak (3 nm FWHM in Lu 2 O 3 [11]) and the pump beam (above 5 nm FWHM).…”

“…In the simulations we assumed ρ = 0.77, accounting for the double pass Fresnel losses on the crystal surface (transmission 0.902) and 5% losses on the other optics. The local power dissipation in the sample depends on the local balance between spontaneous decay rate (which is assumed to occur at a wavelength λ F = 1015.6 nm, corresponding to the average of the fluorescence band, as calculated from the data reported in [11]) and the stimulated emission at the laser wavelength λ L (see for instance Chénais et al [28]). In absence of other decay processes, the dissipated power distribution is then given by…”

“…Since their appearance on the scene, polycrystalline transparent materials of cubic structure doped [1][2][3][4] with rare earths as Nd 3+ [5][6][7] and Yb 3+ [8][9][10], are found to be appealing as laser gain materials showing all their potentiality in term of shortness of the pulse [11][12][13], average power level and beam quality. In consequence of that, in the past years many efforts have been made to improve and refine the techniques of fabrication paving the way to a new class of diode-pumped solid-state lasers.…”

Preparation and characterization of transparent Nd:YAG ceramics

“…Two types of ceramics processing were successfully demonstrated: l "wet" method developed by Yanagitani and Ueda group [4][5][6][7][8], l "dry" method developed by group of Ikesue and Taira [1][2][3]9]. The ceramics made of polycrystalline Y 3 Al 4 O 12 [1][2][3][4][5]14,15,32,33], Lu 3 Al 4 O 12 [13], Y 2 O 3 [6,8,16,18,19,21,22], and Y 3 ScAl 4 O 12 [9] doped with neodymium, ytterbium, chro− mium, and erbium were prepared and showed excellent per− formance in experiments. The optical ceramics can be pro− duced till now from the cubic crystals, however, intensive ef− forts are continued to produce ceramics from anisotropic crystals as vanadates or sapphires.…”

“…For the Nd:YAG ceramics of matured technology their benefits in comparison to the crystalline Nd:YAG can be summarized as follows [33]: Several types of efficient diode pumped lasers made of ceramic materials as microchips [23], composite Q−swit− ched lasers [31], mode−locked lasers [13,21,22,24], high power oscillators [25,26,30,32] were demonstrated. Due to unique properties of advanced engineered ceramic Nd:YAG square slabs produced by Konoshima, the highest reported power of 67 kW in 2×diffraction limits was demonstrated in 2006 [32].…”