Intracavity-pumped 209-μm Ho:YAG laser

Abstract

The 2.09-microm Ho:YAG (5)I(7) ? (5)I(8) laser transition is intracavity pumped by a Tm:YAG laser. Separate Tm:YAG and Ho:YAG crystals share a single laser cavity, the Tm:YAG crystal is pumped at 785 nm, and the resulting 2.01-microm Tm(3+) laser emission pumps the Ho:YAG crystal. The slope efficiency of the 2.09-microm Ho(3+) laser output is 42% of the absorbed 785-nm pump power.

Intra-cavity side-pumped Ho:YAG laser

“…Codoping of the same crystal with thulium and holmium is a compact solution, [5,6], but it can lead to severe co-operative upconversion reducing the energy storage capacity, [7], particularly in a YAG host. Alternatively one can use separate thulium and holmium doped crystals within a common laser cavity, as first demonstrated by Stoneman and Esterowitz, [8]. However, there is limited scope for brightness-scaling the Holmium output in such an intracavity-pumped configuration, as the thermal loads in the respective crystals ultimately degrade the performance of the collinearly-coupled cavities.…”

“…This also allows the use of relatively low holmium doping levels to reduce Ho:Ho upconversion, [15]. Although pumping of a holmium laser by placing it inside the cavity of a thulium laser has been demonstrated by several authors, [8,16,17], if the crystals share a common cavity, [8,16], the thermal lensing in both crystals can seriously affect the beam quality of the Ho:YAG output. To tackle this problem, Schellhorn et al, [17], introduced a novel configuration whereby the Ho:YAG laser cavity was partly decoupled from the Tm:YLF cavity by polarization.…”

A Resonantly Pumped Single-Longitudinal Mode Ho:Sc2SiO5 Laser with Two Fabry–Perot Etalons

“…In this paper, Sc 2 SiO 5 (SSO) is considered to be a potential Ho single-doped laser gain medium. Compared with the common Ho-doped crystals, such as Ho:YLF and Ho:YAG [18,19], there are several outstanding superiorities for the Ho:SSO crystal host, such as large energy splitting (∆E = 712 cm −1 ) and high thermal conductivity. Additionally, the widths of the absorption and the emission spectra are very large, the full width at half maximum (FWHM) of which are 59 nm and 193 nm, respectively [20].…”

Diode-pumped Q-switched Tm:YAP laser with a pump recycling scheme

“…Here, 2-µ m Q-switched lasers were very attractive and necessary sources for optical parametric oscillators (OPOs) and solid-state lasers further in the mid-infrared spectral region [2][3][4]. The rare-earth ion Tm 3+ doped laser materials were emerging as interesting active media for the 2-µ m region due to the possibility of pumping directly by a high-power laser diode emitting at around 800 nm [5][6][7][8].…”