Ring photorefractive oscillator with linear cavity distortions

The spatial structure of the output beam from a ring photorefractive coherent oscillator with imperfectly aligned cavity mirrors is studied. Increasing the tilt angle of the cavity mirror gives rise to the appearance of additional modes, spatially separated from the ordinary phase conjugated one, including high-order transverse and axial modes of the cavity. A simple expression predicting the angular positions of the additional components, is derived from the phase condition of oscillation.<
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