Ultrahigh speed z-scanning optics for 3-D and high depth of field imaging and processing

The ability to rapidly change the focal plane of an optical system or rapidly change the intensity distribution in a given focal plane has many important applications in real-world systems ranging from high powered laser processing to detailed high-resolution microscopy. For all these practical uses, a fast, tunable focus element with a low distortion and high transmission coefficient is necessary yet few viable systems exist. Here we present an overview of the existing technologies to achieve highspeed z-scanning in optical beam delivery systems.
Benefits and disadvantages of the different technologies will be discussed with particular emphasis on the tunable acoustic gradient index of refraction (TAG) Lens. The TAG lens is capable of varying focal length with sub-microsecond temporal resolution and is fast enough to create an effective line-focus without sacrificing optical power.
Fundamental characterization of the TAG lens is presented including the performance metrics such as scanning speed, wavefront aberration, and
optical throughput. Finally, recent application examples in laser
processing, advanced microscopy, and machine vision for process control will be discussed.