Q-switched Ho:YAP laser with a volume bragg grating pumped by a Tm-doped silicon fiber laser

We reported the Q-switched Ho:YAlO₃ laser with a volume Bragg grating pumped by the Tm doped fiber laser. The Ho:YAP laser maximum output energy was 1.04 mJ under the repetition frequency of 5 kHz when the incident power was 12.49 W with the threshold of 2.38 W. The Ho:YAP output wavelength was centered at 2117.9 nm with bandwidth of about 0.3 nm. The pulse width is 23.9 ns.     

Continuous-wave operation of a room-temperature Ho:YAP laser pumped by a Tm:YAP laser

We reported the Ho:YAP laser pumped by the Tm:YAP laser. The Ho:YAP laser maximum output power was 4.91 W when the incident power was 10.1 W with the threshold of 2.63 W. The slope efficiency was 63.7%, corresponding to an optical-to-optical efficiency of 48.6%. The Ho:YAP output wavelength was centered at 2118.2 nm with bandwidth of about 1 nm. We estimate the beam quality to be M² = 1.29.     

A high efficiency Ho:YAlO<Subscript>3</Subscript> laser pumped by Tm:YLF laser with a Volume Bragg Grating

We report a CW Ho:YAlO₃ (Ho:YAP) laser at room temperature pumped by a Tm:YLF laser with a Volume Bragg Grating (VBG) instead of the conventional mirror. The Ho:YAP laser operated at 2117.9 nm with output power 9.12 W. The optical-to-optical conversion efficiency is 60.4% and slope efficiency is 71.2%. The Ho:YAP output wavelength is centered at 2117.9 nm with bandwidth of about 1 nm. The beam quality factor is M ² ∼ 1.29 measured by the traveling knife-edge method.     

Highly-Efficient Ho:S<Subscript>i</Subscript>Sc<Subscript>2</Subscript>O<Subscript>5</Subscript> Laser Pumped by a Narrow Line-Width Tm:YAP Laser at 1.94 <Emphasis Type="Italic">μ</Emphasis>m

We present a highly-efficient continuous-wave Ho:SSO laser pumped by a diode-pumped Tm:YAP laser with a narrow linewidth (NL) of 0.3 nm. With the free-running (FR) Tm:YAP laser, we obtain a maximum output power of 2.23 W at an absorption pump power of 7.2 W, corresponding to an optical conversion efficiency of 31% and a slope efficiency of 42.6%. With the NL Tm:YAP laser, we obtain a maximum output power of 2.88 W at the same absorption pump power. The optical conversion efficiency increases to 40% when the slope efficiency increases to 55.5%. The output linewidth of the Ho:SSO laser is 0.8 nm when we use the Tm:YAP laser with a narrow linewidth of 1.8 nm pumped by a FR Tm:YAP laser. The beam quality also changes from 1.31 to 1.22.     

Room temperature single longitudinal mode Tm,Ho:Yap microchip laser at 2102.6 nm

Room temperature single-longitudinal-mode operation of a c-cut Tm(5%), Ho(0.3%):YAP microchip laser pumped by a fiber-coupled diode-laser is reported. An incident pump power of 3.06 W is used to generate the maximum single-frequency output power of 42 mW at 2102.6 nm, corresponding to optical-to-optical conversion efficiency of 1.4%. To the best of our knowledge, this is the first time to report of Tm,Ho:YAP microchip laser operation on single-frequency at room temperature.     

High power and efficiency of a 2044-nm c-cut Tm, Ho:YAlO3 laser

A high power and efficiency of c-cut Tm, Ho:YAlO₃ (YAP) laser is reported in the paper. The laser operated in continuous wave (CW) mode or Acousto-optical (AO) Q-switched mode at 2044 nm. The Tm, Ho:YAP crystal was cooled at the temperature of 77 K and pumped by a fiber-coupled laser diode (LD) with the centre output wavelength of 794.8 nm. In CW operation, a 9.30-W output power was obtained at a 150-mm physical cavity length, corresponding to a slope efficiency of 42.5%. In Q-switch mode, the output average power of 9 W was achieved at the pulse repetition frequency (PRF) of 10 kHz with a 130-ns pulse width. Moreover, the energy per pulse of 3.54 mJ in 47 ns was acquired at 2.5 kHz with a 75.3-kW peak power.     

Q-switched Ho:YAlO<Subscript>3</Subscript> laser pumped by Tm:YLF laser at room temperature

A Q-switched high efficient Ho:YAlO₃ (Ho:YAP) laser pumped by a diode-pumped Tm:YLF laser at room-temperature is realized. The maximum output energy reaches 1.58 mJ under the repetition frequency of 5 kHz, when the incident pump power is 15.6 W. The pulse width is 22 ns. The wavelength is 2118 nm when the transmission of output coupler is 30%. The beam quality factor is M ² ∼ 1.39 measured by the traveling knife-edge method.     

Continuous-wave operation of a room-temperature Tm: YAP-pumped Ho: YAG laser

We report a continuous-wave (CW) 2.1-μm Ho:YAG laser operating at room temperature pumped by a diode-pumped 1.94-?m Tm:YAP laser.The maximum output power of 1.5 W is obtained from Ho:YAG laser,corresponding to Tm-to-Ho slope efficiency of 17.9% and diode-to-He conversion efficiency of 5.6%.     

A narrow linewidth continuous wave Ho:YAP laser with a volume Bragg grating

We report a diode-pumped CW Ho:YAP laser at room temperature with a volume Bragg grating (VBG) instead of the conventional mirror. The Ho:YAP laser operated at 2117.9 nm, with output power 8.1 W. The optical-to-optical conversion efficiency is 51.9% and slope efficiency is 61.1%. Also, a stable output and a narrow line width less than 0.3 nm FWHM are achieved. This is the first time to report a Ho:YAP laser with a volume Bragg grating.     

1.6 μm Er:YAP and Er:YAG lasers resonantly pumped by Er:glass laser

1623 nm Er:YAP and 1648 nm Er:YAG lasers resonantly pumped by a solid state Er:glass laser operating at 1535 nm were investigated. Laser generation was reached for Er:YAP and two Er:YAG crystals with different Er ion concentration. The maximal output energies were 20 and 45 mJ for Er:YAP and Er:YAG laser systems, respectively.     

High-efficiency resonantly pumped room temperature Ho:YVO4 laser

An efficient 2 μm room temperature Ho:YVO(4) laser resonantly pumped by a 1.94 μm Tm:YAP laser is demonstrated, for the first time to our knowledge, in this Letter. Up to 8.58 W of laser output at 2053 nm is obtained with the optical-to-optical conversion efficiency as much as 41.2%. The output beam had quality of M² factor with Mx(2) of 3.58 and My(2) of 1.76 at 8 W output level. In addition, we also obtained 4.18 W laser output at 2066 nm and 7.04 W at 2040 nm from the Ho:YVO(4) laser with conversion efficiency of 27.8% and 33.8%, respectively.     

Diode pumped operation of tm,Ho:YAP microchip laser

Single-wave length operation of a c-cut Tm (5%), Ho (0.3%):YAP microchip laser pumped by a fiber-coup led diode-laser was reported. Under cryogenic temperature, the output power of 188 mW was obtained under the incident power of 2230 mW, corresponding to the slope efficiency was 12.2%. As much as 168 mW output and slope efficiency of 5.7% was obtained under the pump power of 3400 mW at 291 K. In addition, a maximum single-wave length output power of 60 mW at wavelength of 2130.2 nm and 14 mW at wavelength of 2102.4 nm is demonstrated under 77 and 291 K, respectively.     

High efficient double end-pumped <Emphasis Type="Italic">b</Emphasis>-cut Tm,Ho:YAlO<Subscript>3</Subscript> laser

High efficient continuous wave (CW) and acousto-optical (AO) Q-switched operation of a b-cut Tm,Ho:YAlO₃ (Tm,Ho:YAP) laser are reported in the paper. The Tm,Ho:YAP crystal was cooled by liquid nitrogen and pumped by a fiber-coupled laser diode (LD). Different pump wavelengths were tried in the experiment. An 8.36-W output power was acquired at 2.12 μm in the CW operation with an optical-optical conversion efficiency of 33.3%, and an 8.14-W average power was obtained at the pulse repetition frequency (PRF) of 10 kHz with an optical-optical conversion efficiency of 32.4%.     

Q-switch operation of a c-cut 2132-nm Tm, Ho:YAP laser pumped by a laser diode of 794.3 nm

Q-switch operation of a c-cut Tm (5 at %), Ho (0.3 at %):YAP laser at 2132 nm wavelength were reported in this paper. In the temperature of 77 K, the Tm, Ho:YAP crystal was double end-pumped by a 21.4-W fiber-coupled laser diode (LD) at the center wavelength of 794.3 nm. A 5.29-W Q-switch output power was acquired at pulse repetition frequency (PRF) of 10 kHz, corresponding to an optical-optical conversion efficiency of 24.7% and a slope efficiency of 28.1%. The energy per pulse of 3.57 mJ in 38 ns was achieved at 1.25 kHz with the peak power of 93.9 kW.     

Diode pumped operation of 1 mm Tm,Ho:YAP microchip laser

A single-longitudinal-mode (SLM) operation of a c-cut 1 mm Tm(5%), Ho(0.3%):YAP micro-chip laser pumped by a fiber-coupled diode-laser was reported. Under cryogenic temperature, the output power of 216 mW was obtained under the incident power of 2230 mW, corresponding to the slope efficiency was 13.6%. As much as 133 mW output and slope efficiency of 4.9% was obtained under the pump power of 3000 mW at 291 K. In addition, a maximum SLM output power of 30 mW at wavelength of 2130.56 nm is demonstrated under 77 K.     

Ho:YAG laser intracavity pumped by a diode-pumped Tm:YLF laser

We report a compact Ho:YAG laser that is intracavity pumped by a diode-pumped Tm:YLF laser. Both lasers exhibit pulse mode behavior. Operating both crystals at room temperature (25 degrees C), we obtained 1.6 W of average output at 2.09 microm from the Ho:YAG laser for 15.4 W of diode power incident upon the Tm:YLF rod and a slope efficiency of 21%.     

Continuous wave and AO Q-switch operation of a b-cut Tm,Ho:YAP laser with dual wavelengths pumped by a laser diode of 792 nm

Continuous wave (CW) and AO Q-switch operation of a b-cut Tm,Ho:YAP laser with dual wavelengths were reported in this paper. In the temperature of 77 K, the b-cut Tm,Ho:YAP crystal was double endpumped by a 7.21-W fiber-coupled laser diode (LD) at the center wavelength of 792 nm. A 1.17-W Q-switch output power was acquired at pulse repetition frequency (PRF) of 10 kHz, corresponding to an effective optical-optical conversion efficiency of 25.9% and an effective slope efficiency of 31.5%. The energy per pulse of 0.46 mJ in 100 ns was achieved at 2.5 kHz with the peak power of 4.6 kW.     

Resonantly pumped continuous wave Er:YAP laser

A continuous wave Er:YAP laser pumped by Mgo:PPLN laser locked at 1535 nm was reported. 170 mW of 1609 nm output was achieved under total incident pump power of 7 W at 77 K. The slope efficiency were 5.0 and 3.1% with the cavity length 75 and 140 mm.     

Evaluation of the Performance of an HO:yap Laser Resonantly Pumped by a Thulium Fiber Laser

We investigate the continuous-wave performance of an Ho:YAP laser resonantly pumped by a Tm fiber laser at different output transmittance of 20 %, 30 %, and 50 %. We use a 40 mm long a-cut crystal with 0.5 at.% Ho ion. Our experimental results show that the best power performance is obtained at an output transmittance of 30 %. At an absorbed pump power of 12.1 W, we obtain a maximum output power of 6.1 W at 2118.1 nm with a slope efficiency of 63.4 %. The laser operates at the TEM₀₀ mode with a beam quality factor M ₂ ~ 1.5 measured using a 90/10 knife-edge method.     

6.17-W continuous wave operation of a 2132-nm c-cut Tm,Ho:YAP pumped by a laser diode of 794.3 nm

Continuous wave (CW) operation of a c-cut Tm (5 at %), Ho (0.3 at %):YAP laser at 2132 nm wavelength were reported in this paper. In the temperature of 77 K, the Tm,Ho:YAP crystal was double end-pumped by a 21.4 W fiber-coupled laser diode (LD) at the center wavelength of 794.3 nm. Different resonator lengths and output couplers for the total pump power were tried. The resonator length was 205 mm, and the maximum CW output power of 6.17 W was acquired, corresponding to an optical-optical conversion efficiency of 28.8% and a slope efficiency of 35.6%.