Lasing characteristics of heavily doped single-crystal Fe:ZnSe

Single-Nanosecond-Pulse Lasing in Heavily Doped Fe:ZnSe

“…where T = T(r, t) is the transmittance, T0 = exp [-σabs•nt•l] is the initial transmittance, σabs = 0.97•10 -18 cm 2 is the absorption cross section at room temperature at a wavelength of λp = 2.87 μm, nt is the Fe 2+ ion concentration, = 265 ns is the upperstate lifetime (measured similarly to [17]), l = 2.5 mm is the crystal thickness, h is Planck's constant, νp is the pump radiation frequency, and W0 is the pump radiation energy. The output power over time was determined by integrating the transmitted pump pulse intensity Iout(r,t) = T(r,t) Iin(r,t) over the beam cross section: Our experiments on the transmission of pump radiation and the numerical simulation of this process demonstrate the possibility of obtaining lasing in heavily doped Fe:ZnSе single crystals at pump intensities sufficient for photobleaching.…”

“…There is a clear temporal coincidence between the dips and peaks in the intensity of the profiles of the transmitted pump and lasing pulses, correspondingly. Note that for larger pump spot diameters (6-8 mm), we did not observe such high-frequency and deep laser pulse modulation for heavily doped Fe:ZnSe single crystals [17]. We simulated the lasing process by solving a system of rate equations for the population inversion n(t) = n2(t) -n1(t) and the number of photons in the cavity ϕ(t) [28]:…”

“…In [8], 5-ns pulses were generated in a Fe:ZnSe laser at room temperature upon excitation of the active element with a Cr:ZnSe short-pulse laser. Here, we report the room-temperature generation of single few-nanosecond-long pulses in heavily doped Fe:ZnSe [17] pumped with a Q-switched solid-state laser. The demonstrated lasing regime opens up possibilities for developing novel master oscillators for high-power mid-IR laser systems.…”

Синтез И Исследование Нанопорошков И Керамики Магний-Алюминиевой Шпинели, Активированной Медью

“…Проводятся исследования по использованию других методов активации кристаллов двухвалентными ионами железа. В [7] вертикальным методом Бриджмена были выращены монокристаллы Fe 2+ : ZnSe с однородным распределением железа, предварительно введенного в расплав в виде FeSe. На выращенных кристаллах при концентрации ионов железа n Fe = 6.4 • 10 18 cm −3 была получена энергия лазерного излучения 870 mJ при КПД по отношению к поглощенной мощности накачки HF-лазером, равном 43%, а на кристаллах с n Fe = 5.7 • 10 19 cm −3 приблизительно в тех же условиях получено 245 mJ и 22% соответственно.…”

“…7 • MW/cm 2 . Механизм подачи мишени обеспечивал ее движение таким образом, чтобы по мере испарения мишени положение ее поверхности оставалось в плоскости перетяжки лазерного луча, а относительное движение лазерного луча по поверхности…”