Role of aberration effects in dispersive cavities

An investigation is reported of narrowing of the spectrum in dispersive cavities when the aperture size is reduced. Wavelength tuning as a result of displacement of the axis of an optical system is also considered. These effects are explained without invoking the aberrations associated with an asymmetry of the dispersive components of the system. An analysis is made of the main factors governing the laser frequency tuning as a result of displacement and misalignment of complex systems.