Hi.

Will a plastic linear fresnel lens focus a spot instead of a line if flexed across its line axis ?

 

Just as reference: ---->

 

Focus means deflect. By a different angle according to the distance to the axis and to the position around the axis, so that the deflected light converges to a point.

 

To deflect light, you need an angle between the entering and the exiting interfaces. If both faces are parallel, light will be deflected in the plastic but recover the initial direction as it exits.

 

When bending a part, you keep the faces roughly parallel, so light will be offset by passing through the plastic, but not deflected. It won't focus.