Efficient multiwavelength operation of a diode-pumped Nd:YAlO₃ laser at 1064, 1072 and 1079 nm

Abstract

Polarization investigation of the emission spectrum of Nd ions at the 4 F 3/2 → 4 I 11/2 transition in the b-cut Nd 3+ :YAlO 3 crystal showed that this gain medium is promising for multiwavelength laser operation. A diode-pumped continuous-wave Nd 3+ :YAlO 3 laser with an intracavity retardation plate and a dichroic output coupler demonstrated dual-wavelengths operation at 1064.5 & 1072.6 nm and 1072.6 & 1079.5 nm, as well as triple-wavelengths lasing at 1064.5 & 1072.6 &1079.5 nm. Low intra-cavity losses in the retardation plate allowed achieving a high laser efficiency close to that of a single-wavelength laser. The output power of the triple-wavelength laser reached 1.75 W under a pump power of 6.7 W with a slope conversion efficiency of 32.3 %.

Controlled multiwavelength operation of diode-pumped Nd:YAG laser at 1318, 1338 and 1356 nm with intracavity etalon

“…Multiwavelength generation can occur if the round-trip gain in the laser cavity, which determines the pump threshold condition for several spectral components is identical. Dualwavelength lasers usually utilize specially designed dichroic output couplers and/or a spectrally selective Brewster plate, a phase plate, a Lio filter, or a Fabri-Perot etalon [16][17][18][19][20][21][22][27][28][29]. By varying the reflectivity of the output coupler and fine alignment of spectrally selective elements, it is possible to introduce active, passive or polarization losses at the certain wavelength and, thus, equalize the gain in the laser cavity.…”

A 2 μm Dual-Wavelength Laser at Cryogenic Temperature with Balanced Simultaneous Emission

“…Under fixed resonant cavity parameters, by altering the stimulated emission crosssections, it is possible to control the threshold pump power at different wavelengths and thus achieve dual-wavelength laser emission. One approach to modifying the stimulated emission cross-sections is to change the angle between the laser propagation direction and the crystal axis, or to adjust the cooling temperature of the crystal [23][24][25]. The technique of achieving dual-wavelength lasers through cryogenic temperature tuning exploits the Stark splitting of the laser's upper and lower levels, which is induced by the unique lattice structure of the crystal.…”

An approach for the measurement of focal lengths of a weak thermally-induced negative lens

“…Due to the medium absorption and non-radiation transition, the temperature of the laser medium will therewith increase, resulting in the formation of complex temperature gradients [16][17][18][19][20] . Such temperature gradients will further affect the mechanical and optical features of laser crystals, and lead to the variation of the refractive index, forming the wellknown thermal-induced effects such as the thermal-induced lens and thermal-induced birefringence.…”

“…Such temperature gradients will further affect the mechanical and optical features of laser crystals, and lead to the variation of the refractive index, forming the wellknown thermal-induced effects such as the thermal-induced lens and thermal-induced birefringence. The decrease of outputted laser power and the deterioration of beam quality resulting from the thermal effects greatly limit the application prospect of DPSSLs [20][21][22][23][24][25][26][27].…”