A dynamic trapping of Lamb modes with a frequency cut-off was achieved through local heating of an elastic plate using a continuous-wave (CW) laser. The relatively small variations in material stiffness resulting from the temperature rise proved effective at capturing waves within the heated region, which behaved like a potential well for specific Lamb modes. These trapped modes corresponded precisely to discrete frequencies predicted by the time-independent Schrdinger equation (TISE), reminiscent of the principle quantum number. The number of trapped modes hinges on both the width and depth of the laser-induced thermal potential well, with these variables interrelated via Heisenberg’s uncertainty principle. Furthermore, we observed a high quality factor (Q-factor of approximately 50) attributed to the trapped wave motion within the potential well, offering significant promise for highly precise non-destructive evaluation of thermal and mechanical properties of materials.