One crucial component of digital minilabs for photofinishing is the exposure unit using a modulated RGB laser source. We built a miniaturized source based on frequency-doubled solid state lasers from LASOS, a red laser diode and modulators from LINOS. Because waist size tolerances of the sources exceed the writing spot specs, the anamorphic imaging optics compensates for these tolerances using zoomable micro-optical beam expanders. One element of such a two-lens beam expanders is a lenslet of an array with chirped focal width. Thus, beam expansion is adjusted by selecting the proper lenslet.
Further important features of the RGB source are active pointing stabilization of the solid state lasers by piezo-driven beam steering and power control for each channel to exploit the full dynamic range of the modulators.
The chirped lens arrays are manufactured by replication of circular and cylindrical reflow lens arrays. The micro-optical components together with the stock lenses and the active components are mounted on a stainless steel motherboard, which is shaped to fit into the laser scanning unit of an existing minilab.
- Design of complex optomechanical systems using micro-optical components together with standard lenses
- Manufacturing of chirped micro-lens arrays for beam shaping
- Manufacturing of prototype systems