Polygon mirror scanners in biomedical imaging: A review

We review briefly the different applications of polygonal mirror (PM) scanning heads in biomedical imaging, with a focus on Optical Coherence Tomography (OCT). This overview of biomedical optical systems that employ PMs include: (i) TD (Time Domain) OCT setups, where PM may be utilized for generating the modulation function of the system without separate translation stages; (ii) FD (Fourier Domain) OCT delay line systems, with PM arrays; (iii) broadband laser sources scanned in frequency, for SS (Swept Source) OCT, with the PM placed in various optical configurations; (iv) OCM (Optical Coherence Microscopy) system with double PMs; (v) 2D PM plus galvanometer-based scanner (GS) for fast lateral scanning (not only in OCT, but also in confocal microscopy). We discuss SSs, for which the various PMbased setups used are compared, in their evolution - from on-axis to off-axis polygons - and in the race to obtain higher scan speeds to achieve real-time in vivomedical imaging. The parameters, advantages and drawbacks of these different configurations are pointed out. A necessary comparison is also made with the much faster Fabry-Perot (FP) based SSs. Our approach on PM-based broadband laser sources scanned in frequency, based on a simple off-axis polygon configuration, is also presented. Some of its characteristic mathematical functions are inferred and evaluated. © 2013 Copyright SPIE.