Single-mode ring laser of twin off-axially cut neodymium-doped yttrium örthovanadate crystals in a linear cavity

We analyzed a ring laser made with twin off-axially cut neodymium-doped yttrium örthovanadate (Nd:YVO₄) crystals in a compact linear cavity by using the Jones matrix, figured out its eigenstates including its eigenpolarizations and eigenfrequencies, and confirmed theoretically the single-longitudinal-mode operation of this laser. A spectral measurement of the output laser beam was performed with a scanning Fabry-Perot interferometer, which demonstrated single-mode operation of the ring laser as theoretical analyses had predicted. Experimental observation of the polarization states of the output laser clearly verified that ring circulation of polarized laser beams took place inside the twin off-axially cut Nd:YVO₄ crystals.