Transverse mode locking is receiving renewed attention due to its combination with the formation of optical vortices. In previous investigations, transverse mode locking is focused only on the phase locking of modes in different orders to research the beam pattern dynamics or between frequency-degenerate transverse modes to form a spatially stationary beam pattern with optical vortices. It is experimentally shown that both phase and frequency locking between transverse modes in nonfrequency-degenerate families can be obtained by microchip cavities with high nonlinearity. It is also pointed out that, for a spatiotemporally stationary composed beam pattern formed by locking of transverse modes in different orders, not only should the frequency. but also the propagation parameters. of the beam be coupled.

• Received 26 September 2019
• Revised 30 December 2019
• Accepted 14 January 2020

DOI:https://doi.org/10.1103/PhysRevApplied.13.024010