Low-noise Nd:LaMgAl11O19 laser for use in magnetometry

Abstract

A stable, low-noise, tunable, solid-state laser has been constructed for use in magnetometry. The system is designed specifically for applications in which a rugged, magnetically clean source is required. A La1−xNdxMgAl11O19 (LNA or LMA) laser crystal provides the 1083-nm radiation necessary for optical pumping of gaseous helium, the process on which our magnetometer design is based. Laser characteristics of the 0.5-W SDL 2432 laser-diode-pumped device consist of 112-mW free-running laser output near 1082 nm, a threshold of 35 mW, and an output power of up to 26 mW within a single longitudinal mode at the helium metastable resonance wavelengths, obtained by insertion of an intracavity solid étalon. The structure of the ‘‘hand-held’’ laser unit is presented with particular emphasis on the laser parameters required for low-noise operation of this source at the wavelengths of interest.

Growth and optical properties of Co,Nd:LaMgAl11O19

“…Nd 3 þ ions have been demonstrated to occupy three different sites, instead of one site, in an ideal magnetoplumbite structure. Moreover, the La 3 þ ions substituting for the Al 3 þ also distort the crystal field in the hexagonal structure, leading to large split in the energy levels of the dopants, which contributes to broadening the emission spectra of the Nd 3 þ [24,25,35]. The emission at 1082 nm can be exploited in lasers for tuning to the resonant spectral lines of 3 He and 4 He atoms for use in magnetometry [24,27].…”

“…Nd:LMA has already been utilized as the microchip lasers [25,26] and the He magnetometers with low noise [24,27,28] in modern society due to its special optical merits. In the LMA, the absorption band (1.2-1.6 mm) of the Co 2 þ caused by the substitution of Mg 2 þ sites with tetrahedral symmetry, as well as the emission of the Nd 3 þ ( 4 F 3/2 -4 I 13/2 at 1.3 mm) may enable the Co and Nd co-doped LMA to be a potential self-Q-switched laser material.…”

“…On the other hand, Nd 3 þ -doped LaMgAl 11 O 19 (abbreviated as Nd:LMA) also has been demonstrated to be as a very useful laser gain medium with unique optical and laser properties [22], such as the high quenching concentrations of Nd 3 þ , broad absorption bands of Nd 3 þ in the vicinity of the GaAs laser diode [23,24], long lifetime of the Nd 3 þ ( 4 F 3/2 ), and so on. Nd:LMA has already been utilized as the microchip lasers [25,26] and the He magnetometers with low noise [24,27,28] in modern society due to its special optical merits.…”

Discrete multi-wavelength tuning of a continuous wave diode-pumped Nd:GdVO4laser

“…We believe that further power scaling is possible owing to the good thermo-optical properties of the Nd:GdVO 4 crystal and low quantum defect pumping employed in this work. Such multi-wavelength lasers can have potential applications in optical pumping of helium [7,8] or similar molecular and atomic studies [3][4][5][6], and are attractive for mode locking [27,35,36] and nonlinear frequency conversion through second harmonic, Raman or optical parametric generation [37][38][39][40][41][42][43]. a Observed only at one specific pump power level.…”

“…Apart from the main emission wavelength at 1063 nm, the emission spectrum of Nd:GdVO 4 includes several other emission bands at 1071 nm, 1083 nm, and 1086 nm as shown in figure 1(a). These lines or their frequency doubled versions (535-543 nm) have numerous applications in various areas of molecular and atomic studies [3][4][5][6][7][8] as well as medicine [9,10]. Therefore, development of high power and efficient lasers at these wavelengths is important.…”