Active phase mode locking in a cavity with a controllable Michelson interferometer

This paper presents an experimental and numerical study of the subnanosecond operating regime of a solid-state laser that uses active phase modulation for mode locking and Q-switching of the cavity. The output mirror of the laser cavity, which contains a solid-state quantron with continuous diode pumping, is made in the form of a controllable Michelson interferometer one of whose arms contains an electro-optic phase modulator that dynamically modulates the interferometer’s transmission. The modulation consists of a fast harmonic nanosecond component for mode locking and a slow component in the form of a frequency sequence of microsecond pulses that control the width of the envelope of a train of nanosecond pulses. The paper describes the features of this cavity, analyzes its advantages and disadvantages, and discusses the prospects of developing the given technology for efficient pulse compression, with the possibility of controlling the pulse width by varying the electrical parameters of the electro-optic-modulator driver.