Its efficiency isn’t incredibly high in accordance with the above analysis [31]. One of the most renowned CW laser is the 50-watt FASOR at the Starfire Optical Variety [32]. On 30 May well 2006, the experimental typical worth from the return photons was about 1.eight 107 ph/m2 /s for the 40-watt FASOR, plus the zenith with the laser launch was 0 degrees. Additionally, the angle in the laser beam and geomagnetic field vector was about 28 degrees, comparable for the 30 degrees in Table 1. Additionally, the column density in the sodium layer is practically as a great deal as 4 1013 cm-2 , plus the atmospheric transmission is 0.91. In certain, the laser HBV| Linewidth is 1 104 Hz as an alternative of 0 MHz. Hence, the typical spontaneous emission prices are much more than that in the 0 MHz linewidth laser.For that reason, in Table 2, the calculated value in the return photons for the 0 MHz linewidth laser with 40 W is fundamentally in line with all the actual predicament. Figure 11 L depicts the typical 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, one particular can see that the typical spontaneous emission prices at vD = 0.01 MHz L = 1 MHz for a laser intensity far more than 25 W/m2 . When the linewidth will be the similar as half at vD on the CW laser in the Starfire Optical Range is broadened to be 1 MHz, the return photons will raise about one particular times. At Gemini North (Mauna Kea), the CW laser, which can be mono-mode, has a linewidth at ten MHz, and has a zenith of 45 degrees, the return photons are simulated to become 2.22 106 ph/m2/s by an around ten W laser [33]. The column density on the sodium layer is merely two 1013 cm-2 . If this parameter is taken as four 1013 cm-2 in Table 1, the calculated value is about 4.44 106 ph/m2 /s. This result is relatively close to 5.36 106 ph/m2 /s in Table two.five.3. Effects of Linewidth Broadening on Recoil of the Multi-Mode Laser The multi-mode CW laser which is utilized to excite the sodium laser guide star has the benefit of a wide bandwidth. Even so, its efficiency is not seemingly as great as a single-mode laser [33].This laser has various centers of frequency. The Atpenin A5 In Vivo expression of your laser intensity is [8] I (v D ) = I (0) exp -4 ln 2(vD /vb )2 +kj=-kexp -4 ln 2(vD – jv1 )two /v2 ,(22)exactly where j stands for the amount of modes, k is definitely an integer, v1 is definitely an interval of adjacent modes, v D would be the Doppler shift, I (v D ) = I (0) exp -4 ln two(v D /vb )two is the envelop curve, I (0) would be the peak energy, and vb is definitely the linewidth of envelop curve. v0 could be the mode linewidth.Atmosphere 2021, 12,14 ofTaking v1 = 150 MHz, k = 1, v0 = 104 Hz, and vb = 1 GHz benefits inside a laser spectrum with three modes as in Figure 12.Figure 12. A laser spectrum with 3 modes at v0 = 104 Hz. (The maximum value is normalized.)When the laser mode linewidth is broadened to be 60 MHz, the laser spectrum with 3 modes is shown as Figure 13. In light with the above simulated method, at I = 150 W/m2 , we simulate linewidth broadening influences on recoil in Figure 14. Benefits indicate that the linewidth broadening of 3 modes correctly weakens the recoil peaks from 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 typical 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.
