By employing three reflecting volume Bragg gratings, a near-infrared 4-channel spectral-beam-combining system is demonstrated to present 720 W combined power with a combining efficiency of 94.7%. The combined laser be...By employing three reflecting volume Bragg gratings, a near-infrared 4-channel spectral-beam-combining system is demonstrated to present 720 W combined power with a combining efficiency of 94.7%. The combined laser beam is near-diffraction-limited with a beam factor M^2-1.54. During this 4-channel beam-combining process, no special active cooling measures are used to evaluate the volume Bragg gratings as combining elements are under the higher power laser operation. Thermal expansion and period distortion are verified in a 2 k W 2-channel beam-combining process, and the heat issue in the transmission case is found to be more remarkable than that in the diffraction e-se. Transmitted and diffracted beams experience wave-front aberrations with different degrees, thus leading to distinct beam deterioration.展开更多
We demonstrated a 202 W Tm:YLF slab laser using a reflecting volume Bragg grating(VBG)as an output coupler at room temperature.Two kinds of active heat dissipation methods were used for the VBG to suppress the shift o...We demonstrated a 202 W Tm:YLF slab laser using a reflecting volume Bragg grating(VBG)as an output coupler at room temperature.Two kinds of active heat dissipation methods were used for the VBG to suppress the shift of wavelength caused by its increasing temperature.The maximum continuous wave(CW)output power of 202 W using the microchannel cooling was obtained under the total incident pump power of 553 W,the corresponding slope efficiency and optical-to-optical conversion efficiency were 39.7%and 36.5%,respectively.The central wavelength was 1908.5 nm with the linewidth(full width at half maximum)of 0.57 nm.Meanwhile,with the laser output increasing from 30 to 202 W,the total shift was about 1.0 nm,and the wavelength was limited to two water absorption lines near 1908 nm.The beam quality factors M;were measured to be 2.3 and 4.0 in x and y directions at 202 W.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11474257 and 61605183
文摘By employing three reflecting volume Bragg gratings, a near-infrared 4-channel spectral-beam-combining system is demonstrated to present 720 W combined power with a combining efficiency of 94.7%. The combined laser beam is near-diffraction-limited with a beam factor M^2-1.54. During this 4-channel beam-combining process, no special active cooling measures are used to evaluate the volume Bragg gratings as combining elements are under the higher power laser operation. Thermal expansion and period distortion are verified in a 2 k W 2-channel beam-combining process, and the heat issue in the transmission case is found to be more remarkable than that in the diffraction e-se. Transmitted and diffracted beams experience wave-front aberrations with different degrees, thus leading to distinct beam deterioration.
基金supported by the National Natural Science Foundation of China(No.U20A20214)。
文摘We demonstrated a 202 W Tm:YLF slab laser using a reflecting volume Bragg grating(VBG)as an output coupler at room temperature.Two kinds of active heat dissipation methods were used for the VBG to suppress the shift of wavelength caused by its increasing temperature.The maximum continuous wave(CW)output power of 202 W using the microchannel cooling was obtained under the total incident pump power of 553 W,the corresponding slope efficiency and optical-to-optical conversion efficiency were 39.7%and 36.5%,respectively.The central wavelength was 1908.5 nm with the linewidth(full width at half maximum)of 0.57 nm.Meanwhile,with the laser output increasing from 30 to 202 W,the total shift was about 1.0 nm,and the wavelength was limited to two water absorption lines near 1908 nm.The beam quality factors M;were measured to be 2.3 and 4.0 in x and y directions at 202 W.
