Single-mode oscillation of laser-diode-pumped Nd:YVO_4 microchip lasers

Abstract

Single-mode-oscillation output power of ~103 mW has been observed in 1.1-at.%-doped Nd:YVO(4) pumped with a 500-mW laser diode. Continuous-wave thresholds of ~5.3 mW have been observed with slope efficiencies of greater than 32.4%. The microchip laser can be tuned over 107 GHz, without mode hopping, by heating the laser crystal.

Polarized spectroscopic properties of Nd3+-doped KGd(WO4)2 single crystal

“…The absorption spectra show strong polarized dependence due to the anisotropy of the crystal. Although the peak absorptions of the 4 I 9/2 -4 F 5/2 + 2 H 9/2 transition were all located around 810 nm for all polarizations, which is within the emission wavelengths of the commercial laser diodes, the absorption cross section for the EJN m (26.75 Â 10 À20 cm 2 ) is larger than those for the EJN p (7.81 Â 10 À20 cm 2 ) and EJN g (3.43 Â 10 À20 cm 2 ), and similar to that of the Nd 3+ :YVO 4 crystal for p polarization (29.6 Â 10 À20 cm 2 ) [16,17], which is a wellknown gain medium for microchip lasers [18]. Generally, the thickness of the microchip gain medium is less than 1 mm for obtaining single longitudinal mode laser oscillation, so that crystals with high absorption coefficients should be employed.…”

Laser heated pedestal growth and optical characterization of CaTa2O6 single crystal fiber

“…Compact lasers are attractive because they allow for single mode oscillation without the need for introducing etalons in the laser cavity. By using small crystals or fibers, the cavity length can be shortened so that its mode spacing becomes greater than the gain bandwidth and that way, only one mode oscillates [17]. Moreover, they can be pumped by low cost and commercially available diode lasers, rather than expensive flash lamps, and it is easier to stabilize a short cavity to minimize thermal and mechanical perturbations [18].…”

Self Q-switching effect in a <inline-formula><math altimg="none" display="inline" overflow="scroll"><mrow><mi>Nd</mi><mo>:</mo><msub><mi>YVO</mi><mn>4</mn></msub><mo>∕</mo><mi>KTP</mi></mrow></math></inline-formula> lasing unit

“…8 Note that from observation in Ref. 9, at room temperature the Nd: YVO 4 reaches first the lasing threshold of its first longitudinal mode at 1063.4 nm and at approximately twice the threshold of the first mode a second longitudinal mode reaches its threshold with a wavelength of 1064.2 nm. We assume that a Gaussian inversion density is generated in the four-level laser system when it is pumped by Gaussian intensity profile.…”