Influence of TESG layer viscoelasticity on the imaging properties of microlenses

Microlenses were produced by the irradiation of a layer of tot'hema and eosin sensitized gelatin (TESG) with laser light (second harmonic Nd:YAG, 532?nm). For this research, eight microlenses were written on a dog-bone-shaped TESG layer. After production, microlenses were uniaxially stretched on a tensile testing machine. Each microlens had different amounts of strain (0, 30, 60, 80, 120, 140, 180 and 240% strain). The influence of TESG layer extensibility on the imaging properties of microlenses was characterized by calculating the root mean square wavefront aberration, the modulation transfer function and the geometrical spot diagram. All microlenses had very good imaging properties and the microlens with 0% strain had diffraction-limited performance.