We demonstrated phase-locking in a laser-diode-array-pumped Nd:YVO₄ laser array (15 emitters) using a Talbot cavity. The Nd:YVO₄ slab crystal was coated by dielectric material for claddings and formed a planar waveguide for the vertical mode. To stabilize the horizontal array mode, periodical thermal lenses were generated by controlling the heat flow. The phase-locked waveguide array generated 1.65-W output power, while 2.02 W was available in a standard cavity. Two-peak supermode was demonstrated with the Talbot cavity and was converted to a single peak with a spatial light modulator. We also experimentally and numerically analyzed the characteristics of Talbot phase-locking.