Polarization properties of laser-diode-pumped micro-grained Nd:YAG ceramic lasers

Abstract

Detailed polarization properties have been examined in laser-diode-pumped (LD-pumped) micro-grained ceramic Nd:YAG lasers in different microchip cavity configurations. Stable linearly-polarized single-frequency oscillations, whose polarization direction coincide with that of an LD pump light, were observed in an external cavity scheme. While, in the case of a thin-slice laser scheme with coated reflective ends, elliptically-polarized single-frequency operations took place in the low pump-power regime and dynamic instabilities appeared, featuring self-induced antiphase modulations among counter-rotating circularly-polarized components having slightly different lasing frequencies, with increasing the pump power. PACS: 42.55. Xi,42.55.Rz,42.25.Ja,42.60.Mi

Polarization properties of laser-diode-pumped microchip Nd:YAG ceramic lasers

“…In the framework of vector lasers (Kravtsov, 2004), the angular amplification inhomogeneity has been shown to depend on the orientation of the polarization plane of laser radiation from that of pump radiation, in the form of D(θ,Ψ) = 2A 0 cos 2 (θ -Ψ) as depicted in Fig. 22(b), and the polarization state is almost completely determined by the polarization of the pump radiation for an isotropic cavity with micro-grained Nd:YAG ceramic as described in section 3 Otsuka 2008). For azimuth LD pumping, the laser emission tends to occur such that its polarization direction follows the LD polarization direction within the pumped area.…”

Polarization Properties of Laser-Diode-Pumped Microchip Nd:YAG Ceramic Lasers

“…In the framework of vector lasers (Kravtsov, 2004), the angular amplification inhomogeneity has been shown to depend on the orientation of the polarization plane of laser radiation from that of pump radiation, in the form of D(θ,Ψ) = 2A 0 cos 2 (θ -Ψ) as depicted in Fig. 22(b), www.intechopen.com and the polarization state is almost completely determined by the polarization of the pump radiation for an isotropic cavity with micro-grained Nd:YAG ceramic as described in section 3 Otsuka 2008). For azimuth LD pumping, the laser emission tends to occur such that its polarization direction follows the LD polarization direction within the pumped area.…”

Spontaneous Mathieu-Gauss mode oscillation in micro-grained Nd:YAG ceramic lasers with azimuth laser-diode pumping

“…Weak orthogonal polarization components appeared for smaller off-axis pumping and dual-or ellipticalpolarization modes [4,5] were observed. An example of polarization-dependent oscillation spectra is shown in Fig.…”

“…The collimated linearly polarized LD beam was passed through an anamorphic prism pair and focused onto the sample by a microscope objective lens of NA = 0.25, where the focused beam diameter was about 60 μm. The laser exhibited a single-frequency TEM 00 -mode oscillation, which was linearly polarized along the LD pump-beam polarization direction as a result of the reduced thermal birefringence, for the mode- matched pumping condition, where the threshold pump power was 40 mW [4,5].…”

“…This paper presents the first description, to our best knowledge, of spontaneous non-diffractive beam generation from a microchip laser with azimuth laser-diode (LD) pumping by using micrograined Nd:YAG ceramics, in which thermal birefringence is substantially reduced as a result of the inherent strain relaxations at dense grain boundaries [4,5].…”