Abstract
We demonstrate continuous-wave (cw), cw frequency-doubled, cw mode-locked and Q-switched mode-locked operation of multimode diode-pumped Cr:LiCAF lasers with record average powers. Up to 2.54 W of cw output is obtained around 805 nm at an absorbed pump power of 5.5 W. Using intracavity frequency doubling with a BBO crystal, 0.9 W are generated around 402 nm, corresponding to an optical-to-optical conversion efficiency of 12%. With an intracavity birefringent tuning plate, the fundamental and frequency-doubled laser output is tuned continuously in a broad wavelength range from 745 nm to 885 nm and from 375 to 440 nm, respectively. A saturable Bragg reflector is used to initiate and sustain mode locking. In the cw mode-locked regime, the Cr:LiCAF laser produces 105-fs long pulses near 810 nm with an average power of 0.75 W. The repetition rate is 96.4 MHz, resulting in pulse energies of 7.7 nJ and peak powers of 65 kW. In Q-switched mode-locked operation, pulses with energies above 150 nJ are generated.
Highlights
Cr3+-doped colquiriites (Cr+3:LiSrAlF6 [1], Cr+3:LiCaAlF6 [2] and Cr+3:LiSrGaF6 [3]) offer broad emission bands in the near infrared that allow generation of sub-10-fs light pulses via mode-locking [4,5,6] and widely tunable laser operation in the wavelength range between 700 nm and 1100 nm [7]
The repetition rate was 96.4 MHz, corresponding to pulse energies of 7.7 nJ and peak powers of 65 kW. These are the highest average powers obtained from cw, cw frequency-doubled and cw mode-locked Cr:LiCAF lasers reported to date
Pulses as short as 40 fs might be obtained with saturable Bragg reflector (SBR) mode-locked Cr:LiCAF, we have focused our attention on maximization of average power and for this end it was easier to work with 100-fs level pulses in our experiments
Summary
Cr3+-doped colquiriites (Cr+3:LiSrAlF6 [1], Cr+3:LiCaAlF6 [2] and Cr+3:LiSrGaF6 [3]) offer broad emission bands in the near infrared that allow generation of sub-10-fs light pulses via mode-locking [4,5,6] and widely tunable laser operation in the wavelength range between 700 nm and 1100 nm [7]. Among Cr:colquiriites, Cr:LiCAF has the highest thermal conductivity and maximum thermal quenching temperature combined with minimum quantum defect, excited-state absorption and upconversion rate [12, 16, 17] Despite these facts, earlier studies with Cr:colquiriites mostly focused on Cr:LiSAF due to its broader gain bandwidth, slightly higher gain and availability of high-quality crystals with low passive losses in the order of 0.2% cm−1. The repetition rate was 96.4 MHz, corresponding to pulse energies of 7.7 nJ and peak powers of 65 kW To our knowledge, these are the highest average powers obtained from cw, cw frequency-doubled and cw mode-locked Cr:LiCAF lasers reported to date
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
