A YAG/Yb:YAG/YAG ceramic planar waveguide is manufactured using tape casting combined with vacuum sintering and hot isostatic pressing, which is taken as the laser gain medium to investigate the characteristics of laser amplification. A 1030 nm polarization-maintained (PM) fiber laser is used as the seed laser and a 910-nm diode laser array is used as the pumping source of the amplifier. The pumping light is coupled with the planar waveguide from the end facets. Subsequently, the amplification performances under front-end-pumping and back-end-pumping arc compared, and the amplification performances of dual-end pumping arc experimentally tested. In case of dual-end pumping, when the seed laser power is 136 W, the laser output power is observed to be 1.41 kW and the slope efficiency is up to 41%. To the best of our knowledge, this is the superior output power worldwide for a laser with this type of ceramic planar waveguide.

A quasi continuous wave Nd: YAG planar waveguide laser amplifier with a wavelength of 1319 nm is reported. The seed source is an oscillator based on a side-pumped rod Nd : YAG laser model, and the gain medium of the amplifier is a planar waveguide Nd: YAG. The size of the YAG planar waveguide is 0.6 mm x 10 mm x 60 mm, the central area 0.1 mm x 10 mm x 50 mm is the doped region, and the surrounding area is undoped YAG. The pump source of the amplifier is a diode laser array, which is coupled from the rear end into the planar waveguide gain medium. The seed laser is coupled into the gain medium via the end facet, and a single-pass amplification is introduced. In order to achieve the good heat dissipation, two micro channel heat sinks arc welded onto the Nd:YAG planar waveguide. The end facets arc coated high transmission at 1319, 1064 and 808 nrn. When the driving current of the diode laser arrays is 110 A and the pulse repetition rate is 200 Hz, the output of 36 nm 1319 nm laser is obtained, and the optical to optical efficiency is 8.3%.

We present a 1319 nm Nd:YAG planar waveguide laser amplifier with the optical to optical efficiency of 15%. As far as we all know, this is the highest amplification efficiency for 1319 nm.

Using the tape casting method combined with vacuum sintering and hot isostatic pressing, high-quality planar waveguide YAG/10at.%Yb:YAG/YAG ceramics were successfully prepared. For the sample presintered at 1750 degrees C for 30hours and then HIPed at 1700 degrees C for 3hours in 200 MPa argon, the in-line transmittance reached 82.5% at 400nm and the average grain size was similar to 17.1m. The diffusion behaviors of Yb ions across the contact boundary between the cladding YAG layer and the core Yb:YAG layer were determined by Fick's second law. Then, a 1030nm continuous-wave (CW) Yb:YAG planar waveguide ceramic laser based on the structure of master oscillator power amplification (MOPA) was realized. After a single-pass amplification, the maximum output of the ceramic slab (60x10x1mm(3)) reached 1251W and the corresponding optical-to-optical efficiency was 30.0%, which is the highest output power of a Yb:YAG planar waveguide ceramic laser to the best of our knowledge.

This paper reports a laser diode (LD) end-pumped Yb:YAG slab dual-wavelength laser amplifier with high power working at room temperature. The dual-wavelength stably operates at 1029.6, 1031.5 nm. Based on the broadband fluorescence characteristic of Yb:YAG, the dual-wavelength amplification model is built and corresponding numerical simulation is taken to study the laser spectrum amplification output properties under different pump conditions. 940 nm laser diodes is used to pump the Yb:YAG crystal at two ends. The seed laser with the dual-wavelength spectrum is injected from one end of the crystal and amplified. Experimental results show that continuous-wave (CW) dual-wavelength laser output power of 6.56 kW is acquired when the seed injection is 1.18 kW, which matches the simulation results. These theoretical and experimental researches of dual-wavelength laser amplification can lay the foundation for the applications such as high-power spectral combination, etc.

A kilo-Watt-level continuous-wave dual-wavelength dual-end diode-pumped Yb:YAG slab amplifier is experimentally and theoretically demonstrated. A 1.18 kW seed with stable dual-wavelength operation at 1029.6 and 1031.5 nm can be amplified to the maximum output power of 6.56 kW. We also propose a numerical model to characterize the amplifier system including broad spectrum and temperature-dependent effects. The numerical results of power and spectra evolutions show great agreement with our experiment. To the best of our knowledge, this is the dual-wavelength laser with the highest average power, which has great potential in scaling the application scope of dual-wavelength lasers.