Lasers de frequência única de Nd:YIF e Nd:YVO4 na região do vermelho

Abstract

All solid-state continuous-wave (cw) narrow emission linewidth and tunable red lasers are convenient alternative sources to bulky and expensive dye-lasers for highprecision laser spectroscopy. Single-frequency operation of diode-pumped Nd:YLiF 4 and Nd:YVO 4 cw ring lasers were investigated in the 1.32 -1.34µm range, together with their intracavity second-harmonic generation (SHG) to the red spectral range (0.65 -0.67µm) using either BiB 3 O 6 (BiBO) or periodically-poled KTiOPO 4 (ppKTP) crystals.We report on such a single-end diode-pumped Nd:YVO 4 unidirectional red ring laser containing a type-I cut BiBO nonlinear crystal, yielding a record of 680 mW of single-longitudinal mode (SLM) red output power at 671.1nm without any intra-cavity etalon. For smooth SLM wavelength tuning over the full gain bandwidth (∼4 nm), a partially-coated (R = 40%) 100µm-thin etalon was found necessary, reducing the maximum SLM power (at 671.15 nm) to 380 mW. At 1342.5nm and with a T = 2% transmission output coupler, the laser provided an optimal 1.5W of single-frequency power.We demonstrate also optimal intracavity SHG of a Nd:YLF ring laser in the π-polarization (λ = 1321.5nm) using a ppKTP. The laser yielded 1.4 W of singlefrequency red power at 660.5 nm, as much as the maximum fundamental power that can be extracted from the resonator using an optimal output coupler. With a partiallycoated (R = 25%) thin etalon, the laser was tunable over ∆λ ∼ 1.6nm.