Key Problems Of Adaptive Optics In A Solid-state Laser Oscillator

Since the advent of laser diode pump,solid-stat laser has achieved great progress in terms of efficiency,geometry and weight.It has been widely applied in many fields such as scientific research,medical treatment,industry,national defense and so on,and has become one of the most promising directions in laser.The methods of power amplification in solid-state laser include amplifier and resonator.With imperious demands of higher beam quality and output power in some field,the scheme of resonator is highly concerned because of its simple and compact structure.However,the unavoidable waste heat in the pumping process leads to the wave-front distortion in the resonator,which makes the laser beam quality decrease with the increase of power.The solid state laser in this field is faced with great challenges.In order to explore the active suppression technique of the intracavity aberration,the key issues of the intracavity adaptive optics are studied in this paper.Firstly,two physical models including gain medium,resonator and intracavity adaptive optics system are established based on physical optics.The first one: after analyzing the limitations of traditional intracavity adaptive optics of wave-front sensor-less,the corresponding improvement idea has been proposed,and the physical model are established;second: through the analysis the physical nature of intracavity adaptive optics based on probe laser,a physical model of the system is established.In addition the control algorithm is deduced.The establishment of the above two models provides the necessary numerical analysis and simulation tools for solving the key problems of adaptive correction of intracavity aberration.Secondly,the key problem of intracavity tilt compensation is solved by using the model established before.The shortcomings of the existing intracavity tilt compensation methods are analyzed,the method of adaptive intracavity tilt compensation is proposed,and numerical simulation and experimental results demonstrate that the method is effective and feasible.Finally,The existing technology of the intracavity aberration compensation method is analyzed.It is pointed out that the key to understand the compensation problem of the resonator aberration is how to solve the non-conjugate correction within the standing wave unstable resonator.In addition,we proposed a scheme of the intracavity adaptive correction within a circular the negative branch unstable resonator.A solid-state slab laser with the negative-branch confocal unstable ring resonator is developed.The intracavity aberration correction is investigated with simulations.