Abstract
The Talbot cavity is one passive phase-locking technique for array lasers whose study is attractive due to
its inherent simplicity. This paper describes the principle of the Talbot cavity and the obstacles that are
impeding its commercial success. This paper also introduces our research into it using waveguide lasers.
The Talbot cavity uses a compact, low-cost, high-gain waveguide laser array and successfully
synchronizes the phases of the laser array while maintaining high slope efficiency. We also proposed
and realized intra-Talbot-cavity frequency-doubling to convert an array of out-of-phase lasers into inphase
lasers because a conventional Talbot cavity produces an out-of-phase laser array. By placing a
nonlinear crystal in a Talbot cavity, the Talbot cavity generates an out-of-phased fundamental wave
array, which is converted into an in-phase-locked second harmonic wave array at the nonlinear crystal.
