Abstract Prototype optical microscopes, built to pursue developments in advanced imaging techniques, need specific opto‐mechanical constructions: preferably with high flexibility in the elements' arrangement, easy access to the optical paths, straightforward integration with external optical subsystems—light sources and detectors—as well as good mechanical stability. Typically they are either built around an adapted commercial microscope body or as a home‐brewed setups, based on standard opto‐mechanical elements, and neither solution delivers the desired characteristics. We developed a series of versatile microscope design for prototype optical microscopes in various configurations that use folding mirror(s) to maintain the optical paths horizontal throughout most of the setup. All prototypes use many standard opto‐mechanics in the excitation and detection paths, which simplifies the construction and maintenance of the microscopes. The proposed opto‐mechanical arrangement proved to be useful in building an upright as well as inverted microscopes, in particular Raman microscopes in various configurations. Horizontal arrangement simplified greatly the optical alignment and enabled for fast modifications in the setup—both key advantages at the prototyping stage. Last but not least, the laser safety of the optical system increased. The versatile microscope platform, based around the idea of the horizontal beam arrangement, can easily be adopted to many microscope configurations and to a variety of components that potential users might want to incorporate into them. Research Highlights We design, fabricate, and test a compact, versatile opto‐mechanics for prototyping optical microscopes in various configurations. Horizontal layout along most of the optical paths provides excellent access to the light beams, allows for using standard components and increases the laser safety.

Versatile, open‐access opto‐mechanics design for optical microscopes prototyping