Abstract: The building of systems on breadboards such as optomechanical systems using reference stop assemblies is presented. Each reference stop assembly has a threaded base engageable with the breadboard to removably mount the reference stop assembly thereto, a support shaft connected to the threaded base and a reference ball. The reference ball is captively mounted to the support shaft and has a translational play in a plane perpendicular to the support shaft. The reference stop assembly also includes a clamping member mounted to the support shaft over the reference ball. The reference stop assembly is configured such that, when the reference stop assembly is mounted to said breadboard, the support shaft projects normally to the mounting surface of the breadboard and the clamping member cooperates with the breadboard so as to apply a clamping force to clamp the reference ball against a circular seat of a mounting hole on the breadboard.

Abstract: An ultrasound transducer includes a first piezoelectric layer stacked on a second piezoelectric layer to form a stack. The first piezoelectric layer has one major face metallized to form a first array of electrodes and the other major face metallized to form a first ground electrode. The second piezoelectric layer has one major face metallized to form a second array of electrodes and the other major face metallized to form a second ground electrode, the second array of electrodes oriented at an angle to the first array of electrodes. The second piezoelectric layer has a thickness such that an overall thickness of the stack is equal to an uneven number of half-wavelengths of an acoustic wave to be generated when the first piezoelectric layer and the second piezoelectric layer are independently operated. The ultrasound transducer also includes an acoustic impedance adaptation layer, an acoustic damping layer, and a stiffener.