Analysis of piezoceramics by using optical systems usually requires reflective surfaces. The usual solution to mirror the piezoceramic surface are the optical polishing with gold deposition, or sticking small rigid mirrors. The former solution is difficult to apply in surface with complex shapes. In the latter solution, by sticking a 200um mirror to the piezoceramic surface, it was detected that when piezoceramic are excited in the kHz range, it behaves as unilaminar actuator. In addition, usually not to much attention is paid to the way the piezoceramic is held in the laser interferometer. However, it was noticed that the measured displacements are also highly affected by the mechanical boundary conditions defined by the piezoceramic holder design. Therefore, in this work, both influences are analyzed by combining experimental and computational techniques, and it is discussed how these problems can be solved by using simple solutions. The experimental results are obtained by using laser interferometer and electrical admittance analysis techniques. These results are compared with computational simulations done by using finite element method in ANSYS software. This comparison was very important since it allowed us not only to detect these problems but also to check and evaluate the experimental set up during tests. Simulations and tests are conducted by considering piezoceramics with and without mirror. These problems are isolated, and separately simulated and studied. Experimental measurements are conducted by considering static and transient (one 10kHz sine cycle) piezoceramic excitation. Experimental and simulated data comparison shows a good agreement, and the effect of the mirror and mechanical holder are successfully understood.