Microfabrication of fiber optic scanners

A cantilevered optical fiber is micromachined to function as a miniature resonant opto-mechanical scanner. By driving the base of the cantilevered fiber at a resonance frequency using a piezoelectric actuator, the free end of the cantilever beam becomes a scanned light source. The fiber scanners are designed to achieve wide field-of-view (FOV) and high scan frequency. We employ a non-linearly tapered profile fiber to achieve scan amplitudes of 1 mm at scan frequencies above 20 KHz. Scan angles of over 120 degree(s) (full angle) have been achieved. Higher order modes are also employed for scanning applications that require compactness while maintaining large angular FOV. Etching techniques are used to create the non-linearly tapered sections in single mode optical fiber. Additionally, micro-lenses are fabricated on the tips of the etched fibers, with lens diameters as small as 15 microns. Such lenses are capable of reducing the divergence angle of the emitted light to 5 degree(s) (full angle), with greater reduction expected by employing novel lens shaping techniques. Microfabricated optical fiber scanners have display applications ranging from micro-optical displays to larger panoramic displays. Applications for micro-image acquisition include small barcode readers to medical endoscopes.