Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity
To increase the efficiency of laser oscillators by overcoming losses, the unsaturated gain must be increased. For this purpose, high-intensity pumping, typically higher than 100 kW/cm<sup>2</sup>, is effective. However, the temperature increase and strong thermo-optic effects of the gain...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-11-01
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| Series: | Photonics |
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| Online Access: | https://www.mdpi.com/2304-6732/10/11/1239 |
| _version_ | 1797458027854430208 |
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| author | Sakae Kawato |
| author_facet | Sakae Kawato |
| author_sort | Sakae Kawato |
| collection | DOAJ |
| description | To increase the efficiency of laser oscillators by overcoming losses, the unsaturated gain must be increased. For this purpose, high-intensity pumping, typically higher than 100 kW/cm<sup>2</sup>, is effective. However, the temperature increase and strong thermo-optic effects of the gain medium have been pointed out as obstacles to high efficiency in solid-state lasers. Therefore, the effect of high pump intensity on the laser mode tunability required for high efficiency is investigated by studying the dependence of the laser threshold on the cavity length using a continuous-wave hemispherical short-cavity laser. The results show that the laser mode can be tuned with sufficient range and precision for high efficiency under various loss conditions regardless of the high pump intensity and are in qualitative agreement with a simple theory. Furthermore, according to the heat transport theory, microchip Yb:YAG, the gain medium of this study, does not have a high cooling efficiency, but the maximum temperature increase is estimated to be only about 12 K despite the high pump intensity of about 110 kW/cm<sup>2</sup>. This is because it is the pump power, not the pump intensity, that is proportional to the temperature increase, as the maximum pump power is only 900 mW. These results indicate that high-intensity pumping is a promising approach to achieve efficient lasing at low cost. |
| first_indexed | 2024-03-09T16:31:11Z |
| format | Article |
| id | doaj.art-36c27c9f07e64bdf88cab37bab9bee10 |
| institution | Directory Open Access Journal |
| issn | 2304-6732 |
| language | English |
| last_indexed | 2024-03-09T16:31:11Z |
| publishDate | 2023-11-01 |
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| series | Photonics |
| spelling | doaj.art-36c27c9f07e64bdf88cab37bab9bee102023-11-24T15:01:31ZengMDPI AGPhotonics2304-67322023-11-011011123910.3390/photonics10111239Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short CavitySakae Kawato0Faculty of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, JapanTo increase the efficiency of laser oscillators by overcoming losses, the unsaturated gain must be increased. For this purpose, high-intensity pumping, typically higher than 100 kW/cm<sup>2</sup>, is effective. However, the temperature increase and strong thermo-optic effects of the gain medium have been pointed out as obstacles to high efficiency in solid-state lasers. Therefore, the effect of high pump intensity on the laser mode tunability required for high efficiency is investigated by studying the dependence of the laser threshold on the cavity length using a continuous-wave hemispherical short-cavity laser. The results show that the laser mode can be tuned with sufficient range and precision for high efficiency under various loss conditions regardless of the high pump intensity and are in qualitative agreement with a simple theory. Furthermore, according to the heat transport theory, microchip Yb:YAG, the gain medium of this study, does not have a high cooling efficiency, but the maximum temperature increase is estimated to be only about 12 K despite the high pump intensity of about 110 kW/cm<sup>2</sup>. This is because it is the pump power, not the pump intensity, that is proportional to the temperature increase, as the maximum pump power is only 900 mW. These results indicate that high-intensity pumping is a promising approach to achieve efficient lasing at low cost.https://www.mdpi.com/2304-6732/10/11/1239thermal focusinghigh efficiencyhigh-gainhigh-intensity pumpinggain medium temperature increasemode tunability |
| spellingShingle | Sakae Kawato Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity Photonics thermal focusing high efficiency high-gain high-intensity pumping gain medium temperature increase mode tunability |
| title | Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity |
| title_full | Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity |
| title_fullStr | Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity |
| title_full_unstemmed | Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity |
| title_short | Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity |
| title_sort | influence of high intensity pumping on gain medium temperature increase and laser mode tunability in a hemispherical short cavity |
| topic | thermal focusing high efficiency high-gain high-intensity pumping gain medium temperature increase mode tunability |
| url | https://www.mdpi.com/2304-6732/10/11/1239 |
| work_keys_str_mv | AT sakaekawato influenceofhighintensitypumpingongainmediumtemperatureincreaseandlasermodetunabilityinahemisphericalshortcavity |