With pumping by a Ti:sapphire laser, the cw laser characteristic of a 5.6\mathrm{at.}\text{\hspace{0.17em}\%} , 0.5\mathrm{mm}\mathrm{thick} {\mathrm{Nd}}^{3+}:{\mathrm{LaB}}_3{\mathrm{O}}_6 cleavage microchip in an end-pumped plano–plano resonator is researched. A slope efficiency of up to 49% and a maximum output power of 530\mathrm{mW} are obtained at an absorbed pump power of 1.16\mathrm{W} and an optimal output coupler transmission of 3.2%. Choppers with different duty cycles are used to change the thermal effects in the microchip, and the influences of thermal effects on the laser characteristics of the {\mathrm{Nd}}^{3+}:{\mathrm{LaB}}_3{\mathrm{O}}_6 cleavage microchip are investigated.