Gain competition in orthogonally linearly polarized Nd:YVO₄laser

Abstract

The gain competition is reported in an orthogonally linearly polarized (OLP) Nd:YVO4 laser. Two a–cut Nd:YVO4 crystals with their c–axes mutually orthogonal are employed as the gain medium. The wave equations for the gain-coupled polarized modes are derived and solved. A 32.7 W OLP laser was obtained and the output performances of the OLP laser are investigated experimentally and theoretically. The theoretical results agree well with the experimental ones, which indicates that the gain competition mechanism affects the output performance of this type of OLP laser significantly.

Amplitude and phase modulation of optical feedback in a-cut Nd:YVO4 laser with a birefringent external cavity

“…The Nd:YVO 4 laser can output stable polarized light [19] because its gain medium has a large natural birefringence and the gain coefficient differs greatly between the orthogonal polarization eigenstates. The dual effects of external interference and self-mixing interference with a WP in the external cavity of Nd:YVO 4 laser were studied [20].…”

Exploiting birefringent thermal lensing effect to manipulate polarization states of an Nd:YVO_4 self-mode-locked laser

“…Recently, much attention has been paid to study the orthogonally polarized dualwavelength mode-locked lasers for practical applications including asynchronous optical sampling, control of magnetization, laser spectroscopy, and optical communication [8][9][10][11][12]. To realize an orthogonally polarized dual-wavelength laser [13][14][15][16][17], it is prerequisite to balance the gain-to-loss conditions for the orthogonally polarized states. For a conventional acut Nd:YVO 4 crystal where the π-polarization (parallel to the crystallographic c axis) predominates the laser oscillation, an additional intracavity birefringent element [18][19][20] or a wedged gain crystal [21,22] is frequently required to balance the gain competition between the π-and σ-polarization (perpendicular to c axis) states.…”