An apparatus for coupling light between input and output waveguides includes a substrate, an input waveguide disposed on the substrate and comprising a first optical axis, and an output waveguide disposed on the substrate and comprising a second optical axis vertically offset from the first optical axis. Each of the angle adjusting devices includes a connecting member formed with a locking pawl, and a pivot member pivotally mounted on the connecting member and formed with locking grooves. The instructions of the instruction loop are fetched from a program memory. The muntin clip to be used with muntin bars and spacer frames having a range of different dimensions and configurations. The stand can generally be removed and repositioned, or affixed to another object to be displayed.