Endomicroscopy - Biomedical Optical Imaging Technologies: Design and Applications - page 268

Fig. 8.7 Two general cases of the single-mode fiber scanning: ( a ) actuating a fiber at its first mode
resonant frequency resulting in large tip displacement and ( b ) second mode frequency resonance
causing small tip movement at large angular changes [ 19 ]
Fig. 8.8 MEMS scanner for an endoscopic applications. a SEM scanner image and b Electrical
schematic of the MEMS device [ 44 ]
one delivering illumination light and one for collection, which intersect at the object
plane [ 45 ]. This “dual-axes” or “theta confocal” configuration offers good optical
sectioning with well-matched resolution in axial and lateral directions; however, the
FOV, as determined by the available MEMS scanner range, remains limited.
MEMS mirror scanners are usually based on the application of electrostatic comb
drives (see example in Fig. 8.8 [ 44 ]). A change of potential between comb electrodes
can introduce both linear and angular movement of electrodes, with angles ranging