Optimizing mode-to-pump ratio in end-pumped Nd:GdVO4 laser at 1342 nm considering the energy-transfer-upconversion

Diode-end-pumped continuous wave single-longitudinal-mode Nd:GdVO4laser at 1342 nm

“…It can be seen that the experimental data are in good agreement with the theoretical calculated results with the ETU effects (solid line). Besides, from this figure we can also see that the influence of ETU effects is more serious as the increase of the mode-to-pump ratio; that is because of the higher losses arising from ETU effects for the increasing mode-to-pump ratio as shown in our previous work [21,22]. Consequently, the optimum mode-to-pump ratio is about 0.65 for the present case.…”

“…Many works [21,[27][28][29] have shown that the thermally induced diffraction losses are increasing functions of mode-to-pump ratio. Our previous work [21,22] has shown that the losses from ETU effects are also increasing functions of mode-to-pump ratio for slightly higher pump power. However, it is known that the conversion efficiency of lasers is also an increasing function of mode-to-pump ratio by solving the rate equation without thermally induced diffraction losses and ETU effects.…”

“…In the past analytical modeling, including ETU effects lasers, has been done and the influence of ETU effects on the threshold [8,12,13], output power [12,13] and thermal lensing effect [9,11,12,15,[18][19][20] has also been investigated. In our previous work [21,22], the ETU losses as functions of the ratio between laser cavity mode and pump beam size in the laser medium and pump power were investigated; we concluded that the ETU losses were increasing functions of mode-to-pump ratio at slightly higher pump power and decreasing functions of pump power.…”

“…τ c 2L c ∕cδ is the cavity photon lifetime, δ is the round-trip losses, and can be written as [21,22,[27][28][29] δ T δ f δ d ; (6) where T is the transmission of the output coupler, δ f is the nondiffraction round-trip losses, and δ d is the diffraction loss due to the thermally induced spherical aberration and can be calculated by…”

A diode-end-pumped continuous-wave single-longitudinal-mode Nd:GdV O4–LBO red laser at 670 nm

“…Many works [16][17][18][19][20] have revealed that the fundamental wave output power is a function of the mode-to-pump ratio ω 0 /ω pa , and there exists an optimum mode-to-pump ratio for maximum fundamental wave output power considering the thermally induced diffraction losses obtained by changing the cavity length. Here ω pa is the average pump beam radius inside the laser medium and is given by [21]…”