A diode-pumped passivelyQ-switched Tm,Ho:YAP laser with a single-walled carbon nanotube

Abstract

In this letter we present diode-pumped continuous wave (CW) and passively Q-switched a-cut and b-cut Tm,Ho:YAP lasers with a single-walled carbon nanotube saturable absorber (SWCNT-SA). In the CW regime, a maximum output power of 1.61 W at 2118.3 nm corresponding to a slope efficiency of 33.7% and a maximum output power of 1.23 W with a slope efficiency of 28.7% at 2129.6 nm were achieved from the a- and b-cut Tm,Ho:YAP lasers, respectively. With a SWCNT employed as the saturable absorber, passively Q-switched a- and b-cut Tm,Ho:YAP lasers were both realized. The a-cut Tm,Ho:YAP laser generated a 245 ns pulse at 2128.3 nm with a repetition rate of 400 kHz, while the b-cut Tm,Ho:YAP laser produced a 135 ns pulse at 2130 nm with a repetition rate of 245 kHz.

Passive Q-switching of a Tm,Ho:KLu(WO_4)_2 microchip laser by a Cr:ZnS saturable absorber

“…With higher modulation depth of the SA (α 0 SA 3.5%), a pulse duration of 9 ns was achieved, the shortest ever reported for a PQS Tm,Ho-doped laser. At a pulse energy of 10.4 μJ, this corresponds to a record peak power of 1.15 kW, the highest ever extracted from a room-temperature PQS Tm,Ho laser, exceeding >50 times the previous results [19][20][21][22][23]. A theoretical model of a quasi-three-level laser system PQS with a "slow" SA is developed.…”

“…Passive Q-switched laser operation at room temperature is more favorable to benefit from the compactness of the cavity. A comparison of passively Q-switched Tm,Ho bulk lasers reported so far [19][20][21][22][23] is presented in Table 2. Two types of SAs were employed in these lasers, namely, Cr:ZnS and carbon nanostructures (graphene and single-walled carbon nanotubes, SWCNTs).…”

“…We are aware of only one report on a PQS Tm,Ho microchip laser [19]. However, due to one particular limitation of the SA used in [19] (single-layer graphene), namely, the low modulation depth, this laser generated 200 ns∕ 0.2 μJ pulses with a peak power of only ∼1 W. Several previous studies were devoted to PQS Tm,Ho bulk lasers using LiYF 4 , LiLuF 4 , YAlO 3 , and YVO 4 host crystals and Cr 2 :ZnS or carbon nanostructures as SAs [20][21][22][23]. However, in such lasers, the typical pulse durations were still a few hundred nanoseconds (ns) and the peak power did not exceed a few tens of watts (W).…”

Diode-pumped passivelyQ-switched dual-wavelengthc-cut Tm,Ho:LLF laser at 2 μm

“…Using a Cr:ZnS crystal as an SA, PQS a-cut Tm,Ho:YLF 1612-2011/14/035801+05$33.00 and Tm,Ho:LLF lasers with microsecond long pulse were reported, which could be used as the optical sources for 2 µm coherent Doppler laser lidars [15,16]. Recently, the PQS Tm,Ho:YAP laser using a single-walled carbon nanotube SA was also realized, with a minimum pulse width of 135 ns and a maximum pulse energy of 4.67 µJ [17]. It can be noted that the above Tm-Ho lasers have a relatively wide pulse duration.…”

Polarization switching and optical bistability in the diode-pumped Tm,Ho:LLF laser

“…Recently, the dual-wavelength lasers at the 2 µm spectral region have attracted more and more attention. The dual-wavelength lasers such as Tm,Ho:GdVO 4 , Tm,Ho:YVO 4 , Ho,Tm:KLu(WO 4 ), and Tm,Ho:YAP have been reported [21][22][23][24][25]. But, the polarization characteristics of these dual-wavelength lasers at 2 µm were not given.…”