A reciprocating shaft assembly in a reciprocating saw moves in a reciprocal motion and drives a saw blade via a blade holder. The low resistance DBR may be used as a top output mirror of a tunnel junction VCSEL that reduces resistance and optical losses by reducing the amount of p-type material within the device. The AD converter has a ground pin voltage reference at least as negative as the most negative point of the input signal to be processed. In a second embodiment, a secondary substrate having conductive traces formed thereon is secured to the transparent substrate. The dielectric constant of a dielectric layer deposited by reaction of an organosilicon compound having three or more methyl groups is significantly reduced by further depositing an amorphous hydrogenated silicon carbide layer by reaction of an alkylsilane in a plasma of a relatively inert gas. The reflected light is directed by the lens back to the VIPA generator.