Microlens arrays in special glass type produced by silver ion exchange

The fabrication of gradient-index (GRIN-) lenses and GRIN lens arrays by silver ion exchange is discussed. Thermal and field-assisted exchange processes in a special developed glass type are investigated. Slab-like cylindrical and rod lenses with numerical apertures N.A. up to 0.60 are realized. For applications requiring a low number of high N.A. lenses arrays are formed by assembling single lenses in appropriate sub-mounts. Arrays of low numerical aperture (N.A.<= 0.20) with lenses of down to 32 mu m diameter and diffraction limited performance are formed by field assisted ion exchange using photolithographically patterned glass substates