Single-frequency YAG:Nd3+ laser stabilized by an active standard

An investigation was made of a YAG:Nd³⁺ laser with means for longitudinal and transverse mode selection and with frequency stabilization by an external standard. The longitudinal modes were selected by a Tshaped resonator and an inclined Fabry-Perot interferometer. The external standard was the resonator of an He–Ne laser stabilized at λ = 1.15 μ using the Lamb dip. The frequency stability achieved in this way was 10⁸ for an output power of 300 mW.