Lasing characteristics of laser-pumped Mg₂SiO₄:Cr crystals

Abstract

We consider a mechanism by which dyons (electrically charged magnetic monopoles) can produce both a T-and P-odd (i.e. time-reversal invariance and parity violating) mixed polarizability β (defined by E = −βE · B, where E is the energy change when electric (E) and magnetic (B) fields are applied to a system) and a T-and P-odd interaction between two particles:ψ 1 γ 5 ψ 1ψ2 ψ 2 , where the ψ i are electron and quark spinors. The latter can create atomic and neutron electric dipole moments. From experimental bounds on these we find limits on the properties of dyons. The contribution of dyons to CP violation in K-meson decays is also estimated.

Laser Characteristics of Chromium Doped Forsterite with Ti:Sapphire Laser Excitation

“…From figure 4, it can be seen that the overall conversion efficiency appears to be saturated for absorbed energies above 3 mJ . The same phenomenon was also noticed by Kimaev et al with 1064 nm laser excitation and was attributed to the induced absorption of the excited chromium ions [8] . From the energy level diagram shown in figure 2, it corresponds to the absorptive transition from 3 T 2 ( 3A 1 or 3 B 1 ) to higher levels 3T2 ( 3 P) or 1 T 1 .…”

“…Both pulsed and c .w . laser operation at room temperature have been obtained for Cr :forsterite with laser excitation at 532nm, 578 nm, 629 nm and 1064 nm wavelengths [1,[6][7][8] . Flashlamp pumped Cr :forsterite laser has also been reported [9] .…”

Low‐Temperature Crystallization of Forsterite and Orthoenstatite

“…Reactions (1)-(3), as shown previously, were expected to occur via these procedures. Despite the insolubility of Mg(OMe) 2 and Mg(OEt) 2 in methanol, precipitates were not formed. Liquid-state and solid-state 29 Si NMR measurements were performed to determine whether reactions (1)-(3) really occurred.…”

“…Both exhibited a main peak located at approximately −80 ppm. This peak might be identified as that which is located at −80.7 or −81.2 ppm in the liquid-state NMR spectrum, which corre- spond to silicon elements in double alkoxides such as Si(OMe) 3 (OMg−) or Si(OMe) 2 (OMg−) 2 . The spectrum of the as-prepared specimens with a starting TMOS:Mg compositions of 1.0 exhibited a very broad and weak peak located at approximately −90 ppm, on the shoulder of a main peak.…”

“…1 Recently, chromium-doped forsterite was shown to be a promising active medium for a tunable laser. 2 Consequently, these magnesium silicates were studied extensively. However, it is difficult to obtain homogeneous gels of alkaline-earth silicates, even when prepared by using sol-gel methods from the mixed solutions of silicon alkoxide and alkaline-earth salts.…”