Author Affiliations
1Institute of Laser and Optoelectronics, School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, China2Key Laboratory of Optoelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin, Chinashow less
Fig. 1. Experimental setup of the Nd:YVO4-KGW intracavity Raman laser with Stokes HR coating on one of the crystal end-faces and on a separate mirror.
Fig. 2. Stokes output power and fundamental laser leakage as a function of incident LD pump power, with the two different cavity arrangements.
Fig. 3. Typical Stokes spectra (a), (b) and beam profiles (c), (d) at different Stokes output powers, with the HR-coated KGW crystal.
Fig. 4. Optical efficiency PS_out/PP of the Raman laser as a function of the Stokes and fundamental round-trip losses, with the incident pump power of (a) 24.8 W and (b) 40.9W, respectively. The calculation used a 270-μm fundamental laser radius in the laser crystal, 110-μm fundamental laser radius and Stokes beam radius in the KGW crystal and 0.7% output coupling for the Stokes wave.
Fig. 5. Schematic of the influences of the end-face curvature on the cavity scheme.
Fig. 6. Thermo-optically induced negative thermal lens focal length and (single) end-face curvature induced positive thermal lens focal length as a function of Stokes power generated in the KGW crystal, in p[mm]p orientation. The fundamental and Stokes wavelengths are 1064 and 1177 nm, respectively. The Stokes beam radius in the KGW crystal used in the calculation is 110 μm.
Fig. 7. TEM00 mode Stokes beam size evolution with thermo-optically induced ftn in the KGW crystal with the two different cavity arrangements, with the relationship between ftn and fte considered.
Cavity arrangement with HR mirror M4 | Cavity arrangement with HR coating on KGW |
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Surfaces | 1064 nm | 1177 nm | Surfaces | 1064 nm | 1177 nm |
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SC1 | R = 0.144% | R = 0.22% | SC1 | R = 0.54% | T = 0.03% | SC2 | R = 0.36% | R = 0.23% | SC2 | R = 0.33% | R = 0.12% | SM41 | R = 0.01% | / | | | | SM42 | R = 0.16% | T = 0.037% | | | | Sum of the | | | Sum of the | | | unwanted R | | | unwanted R | | | and T for a | 1.55% | 0.94% | and T for a | 1.94% | 0.27% | round-trip | | | round-trip | | |
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Table 1. The reflectivities of the AR coatings and transmittances of the HR coating of each surface provided by the manufacturers.