Two-Dimensional 2D Microlenses

Figme 7.2 shows the images of the mold and the PDMS microlens fabricated from it. It should be noted that this design caimot modify the light beam along the Z direction. The efficiency of these lenses is then limited to a 2D plane defined by both the X axis and Y axis parallel to the glass substrate—the PDMS layer interface. 

Hsiung et al. did not use a PDMS layer. They utilized a hot embossing process to form microlenses [10]. The hot embossing technique is relatively simple and reliable [11]. The manufacturing process involved three major steps (1) fabrication of the glass-based master mold, (2) fabrication and bonding of the polymethylmethacrylate (PMMA) chips, and (3) insertion of the optic fibers. 

Experimental setup for 2D microlenses. Source Camou, S., Ff. Fujita, and T. Fujii. 2003. Lab on a Chip, 3(1), 40-45. With permission.) 

Fluorescence emission without micro focusing lens 

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