Two-Axis High-Speed Beam-Steering Mirror Design


University of Nevada, Reno researchers Nelson Publicover and John Sutko in the Department of Electrical and Biomedical Engineering and the Department of Pharmacology, respectively, conduct research in the biomedical and medical fields. Their novel design relates to a light-beam steering device whose support platform can be simultaneously rotated in two spatial directions to steer a reflected light beam.

Technology Summary 

Conventional methods of laser beam steering utilize physically separate mirrors mounted on two independent galvanometers (the most common beam-steering device in scanning optical systems), and are used to achieve both x- and y-direction scanning.  Because two separate mirrors are used, the device cannot place the axis of a primary deflection surface in a coupled image plane, and imposes optical limitations.  In some galvanometer systems, frequency response can be limited by factors including the extent of mechanical movement of the mirror(s), and the size/mass of the necessary reflective surface. The low level torque produced by current high-rate two-axis beams hinders the size of the reflective surface to typically less than 1mm.  Such a small clear aperture limits the achievable spatial resolution to much less than that of confocal systems currently available commercially, while placing important limitations on the properties of the optical system that can be used.  Increased mirror size results in a reduction in scan frequency, and an increase in the dynamic deformations of reflective surfaces that diminish the quality of the reflected light and the optical quality of acquired images.

The novel design is a two-axis beam-steering device with a single, large reflective surface.  The device can deflect laser beams, or other illumination beams, in two (x and y) dimensions with a frequency response in the kHz range.  Micro-machined and/or semiconductor structures can be used to form a reflector platform hybridized with closed-loop galvanometers to achieve rapid beam-steering movements.  This method optimizes the achievable spatial resolution and can be configured to generate dual-axis position-feedback signals usable for monitoring and further increasing beam-steering accuracy.

By utilizing two galvanometer attachments in each of the x- and y-dimensions, a more efficient translation of rotational torque is achieved, and allows for sufficient flex in each direction. An insert can be attached to a slot in the rotational shafts of the galvanometers to stabilize the platform, and would allow the platform to rotate completely 360°.  Increased mechanical stability of the support platform is also realized.

Potential Applications

  • Material processing (eg. Marking, scribing, engraving, cutting, and drilling)
  • Biomedical Systems (eg. Optical Coherence Tomography)
  • Microscopy
  • Laser Projection
  • Imaging and Printing
  • Semiconductor Processing
  • Biosensors and surveillance
  • Optical scanning and particle tracking

IP Status
UNR ID#: UNR04-001
Method and Apparatus for Two-Axis, High-Speed Beam Steering
US Patent No.: 7,796,314


Patent Information:
For Information, Contact:
Shannon Sheehan
Manager, Technology Commercialization
University of Nevada, Reno
John Sutko
Nelson Publicover