Its efficiency is not really higher based on the above analysis [31]. By far the most renowned CW laser will be the 50-watt FASOR in the Starfire Optical Variety [32]. On 30 Might 2006, the experimental typical value of your return photons was about 1.eight 107 ph/m2 /s for the 40-watt FASOR, as well as the zenith from the laser launch was 0 degrees. Furthermore, the angle of the laser beam and geomagnetic field vector was about 28 degrees, comparable towards the 30 degrees in Table 1. Additionally, the Fusaric acid site column density from the sodium layer is practically as substantially as four 1013 cm-2 , plus the atmospheric transmission is 0.91. In particular, the laser linewidth is 1 104 Hz rather of 0 MHz. Hence, the typical spontaneous PbTx-2 Cancer emission prices are more than that of the 0 MHz linewidth laser.For that reason, in Table two, the calculated value on the return photons for the 0 MHz linewidth laser with 40 W is basically in line together with the actual circumstance. Figure 11 L depicts the average spontaneous emission rates for the laser linewidth at v D = 0, 0.01, 1 MHz.L Figure 11. Average spontaneous emission rates vs. intensity at v D = 0, 0.01, 1 MHz.L From Figure 11, a single can see that the average spontaneous emission rates at vD = 0.01 MHz L = 1 MHz for a laser intensity extra than 25 W/m2 . If the linewidth are the identical as half at vD in the CW laser in the Starfire Optical Range is broadened to become 1 MHz, the return photons will increase about one particular instances. At Gemini North (Mauna Kea), the CW laser, that is mono-mode, features a linewidth at ten MHz, and features a zenith of 45 degrees, the return photons are simulated to be two.22 106 ph/m2/s by an about 10 W laser [33]. The column density on the sodium layer is merely 2 1013 cm-2 . If this parameter is taken as 4 1013 cm-2 in Table 1, the calculated worth is about four.44 106 ph/m2 /s. This outcome is relatively close to 5.36 106 ph/m2 /s in Table 2.5.three. Effects of Linewidth Broadening on Recoil from the Multi-Mode Laser The multi-mode CW laser that is utilized to excite the sodium laser guide star has the advantage of a wide bandwidth. On the other hand, its efficiency is just not seemingly as good as a single-mode laser [33].This laser has many centers of frequency. The expression of the laser intensity is [8] I (v D ) = I (0) exp -4 ln two(vD /vb )two +kj=-kexp -4 ln 2(vD – jv1 )2 /v2 ,(22)exactly where j stands for the number of modes, k is definitely an integer, v1 is definitely an interval of adjacent modes, v D may be the Doppler shift, I (v D ) = I (0) exp -4 ln 2(v D /vb )two is definitely the envelop curve, I (0) would be the peak energy, and vb is the linewidth of envelop curve. v0 will be the mode linewidth.Atmosphere 2021, 12,14 ofTaking v1 = 150 MHz, k = 1, v0 = 104 Hz, and vb = 1 GHz results inside a laser spectrum with 3 modes as in Figure 12.Figure 12. A laser spectrum with 3 modes at v0 = 104 Hz. (The maximum worth is normalized.)When the laser mode linewidth is broadened to become 60 MHz, the laser spectrum with three modes is shown as Figure 13. In light in the above simulated strategy, at I = 150 W/m2 , we simulate linewidth broadening influences on recoil in Figure 14. Results indicate that the linewidth broadening of three modes efficiently weakens the recoil peaks with the distribution of sodium atoms.Figure 13. A laser spectrum with 3 modes at v0 = six 107 Hz. (The maximum worth is normalized.)Figure 15 depicts the average spontaneous emission rates for the laser intensity from L 0 to 200 W/m2 at v0 = 104 Hz and 60 MHz for the three-mode laser and at D = 0 MHz for the mono-mode laser.Atmosphere 2021, 12,15 of(a) Laser linewid.
