MEMS Based Mechanical Resonant Push-Pull Scanning Endoscope

Abstract

Here we present a microfabricated SU-8 cantilever scanner. Current SU-8 rib waveguide design improved the output beam diameter of our previous design from ~50μm to ~5.0μm, further improves our spatial resolution. The proposed rib waveguide design also allows a relatively large waveguide cross section (4μm in height and 55μm in width) and broader wavelength range in single-mode operation (λ= 0.7μm to 1.3μm) with a minimum transmission loss (85% output transmission efficiency with Gaussian beam profile input). Our design also provides a new means to create a 2-D raster scanning pattern using a microfabricated push-pull actuator, verified by a transient finite element analysis (FEA). The scanner's line resolution and field of view (FOV) have been optimized through a parametric study using modal and harmonic analyses. This optical scanner may find application in the area of endoscopy, where there is a need for a minimally invasive device that reduces patient discomfort.