Intra-cavity frequency-doubling of a Nd:YAG laser passively Q-switched with GaAs

Optimization of GaAs semiconductor saturable absorber Q-switched lasers

“…s 0 and s + are the absorption cross section of EL2 0 and EL2 + , respectively, R is the output coupler reflectivity, L is the loss of the cavity, B is the coupling coefficient of TPA in the GaAs, which is defined as [13] B ¼ 6bhncdðo 0 =o q Þ 2 (4) where b is the absorption coefficient of two photons, o 0 and o q are the spot size of the beam in the gain medium and GaAs wafer, respectively. The small-signal transmission T 0 of GaAs can be expressed by…”

Diode-pumped passively Q-switched mode-locked c-cut Nd:GdVO4 laser with a GaAs coupler

“…where n(r, t) is the average population-inversion density; n 0 is total population density of the EL2 defect level (including EL2 0 and EL2 + ) of GaAs, n + (r, t) is the population density of positively charged EL2 + in GaAs, r 0 and r + are the absorption cross-section of EL2 0 and EL2 + in GaAs, respectively, L is the intrinsic loss,R is the reflectivity at 1.06 lm of the output coupler; s a is the stimulated-radiation lifetime of the gain medium; R in ðrÞ ¼ P in expðÀ2r 2 =x 2 p Þ½1 À expðÀalÞ=ht p px 2 p l is the pump rate, where P in is the pump power, ht p is the single-photon energy of the pump light, x p is the average radius of the pump beam, a is the absorption coefficient of the gain medium, B = 6bhmc(x G /x A ) 2 is the coupling coefficient of twophoton absorption (TPA) in GaAs, b is the two-photon absorption coefficient [23], / G (r, t) and / A (r, t) are the photon densities at the positions of gain medium and GaAs wafer, respectively, and described as [24] / i ðr; tÞ ¼ ðx 2…”

All-Poly-Crystalline Ceramics Nd:YAG/Cr4+:YAG Monolithic Micro-Lasers with Multiple-Beam Output

“…For example, green laser pulses with 2.5-J energy (190-mW average power) were obtained from a Nd:LSB gain medium passively Q-switched by Cr 4+ :YAG and intra-cavity frequency doubled by KTiOPO 4 (KTP) in a linear resonator (Ostroumov et al, 1997). Furthermore, a Nd:YAG laser that was passively Q-switched by GaAs semiconductor and intra-cavity frequency doubled by KTP, in a V-type laser resonator, yielded green laser pulses with 20.5-J energy and ~250-mW average power (Kajava and Gaeta, 1997). Later, a Nd:GdVO 4 -Cr 4+ :YAG-KTP laser with 21-J energy per pulse (average power of ~400 mW) was realized (Liu et al, 2004).…”